VEGETATION AND NOISE ABATEMENT

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VEGETATION AND

NOISE ABATEMENT

Disarikan oleh: soemarno, pdklp-ppsub-2012

1. Kebisingan adalah bunyi yang tidak diinginkan dari usaha atau kegiatan

dalam tingkat dan waktu tertentu yang dapat menimbulkan gangguan

kesehatan manusia dan kenyamanan lingkungan;2. Tingkat kebisingan adalah ukuran energi bunyi

yang dinyatakan dalamsatuan Desibel disingkat dB;

3. Baku tingkat kebisingan adalah batas maksimal tingkat kebisingan yang

diperbolehkan dibuang ke lingkungan dari usaha atau kegiatan sehingga

tidak menimbulkan gangguan kesehatan manusia dan kenyamanan

lingkungan;

Keputusan Menteri Negara Lingkungan HidupNo. 48 Tahun 1996

Tentang : Baku Tingkat Kebisingan

BAKU TINGKAT KEBISINGAN

The Federal Highway Administration (FHWA) prescribes a three-part approach for addressing roadway noise including:

1) source controls and quiet vehicles, 2) reduction measures within highway construction, and 3) developing land adjacent to highways in a way that is

compatible with highway noise.

Jalur hijau sepanjang jalan kampus UB

Foto smno-kampus.ub.-Mei 2012

KEPUTUSAN MENTERI NEGARA LINGKUNGAN HIDUPNO. 48 TAHUN 1996 TANGGAL 25 NOPEMBER 1996

BAKU TINGKAT KEBISINGAN

KEPUTUSAN MENTERI NEGARA LINGKUNGAN HIDUPNO. 48 TAHUN 1996 TANGGAL 25 NOPEMBER 1996

METODA PENGUKURAN, PERHITUNGAN DAN EVALUASI TINGKAT KEBISINGAN LINGKUNGAN

1. Metoda PengukuranPengukuran tingkat kebisingan dapat diiakukan dengan dua cara :1) Cara SederhanaDengan sebuah sound level meter biasa diukur tingkat tekanan bunyi db (A)selama 10 (sepuluh) menit untuk tiap pengukuran. Pembacaan dilakukansetiap 5 (lima) detik.2) Cara LangsungDengan sebuah integrating sound level meter yang mempunyai fasilitaspengukuran LTMS, yaitu Leq dengan waktu ukur setiap 5 detik, dilakukanpengukuran selama 10 (sepuluh) menit.Waktu pengukuran dilakukan selama aktifitas 24 jam (LSM) dencan cara pada sianghari tingkat aktifitas yang paling tinggi selama 10 jam (LS) pada selang waktu06.00 - 22. 00 dan aktifitas dalam hari selama 8 jam (LM) pada selang 22.00 -06.00.Setiap pengukuran harus dapat mewakili selang waktu tertentu denganmenetapkan paling sedikit 4 waktu pengukuran pada siang hari dan pada malamhari paling sedikit 3 waktu pengukuran, sebagai contoh :- L1 diambil pada jam 7.00 mewakli jam 06.00 - 09.00- L2 diambil pada jam 10.00 mewakili jam 09.00 - 11.00- L3 diambil pada jam 15.00 mewakili jam 14.00 - 17.00- L4 diambil pada jam 20.00 mewakili jam 17.00.- 22.00- L5 diambil pada jam 23.00 mewakili jam 22.00 - 24.00- L6 diambil pada jam 01.00 mewakili jam 24.00 - 03.00- L7 diambil pada jam 04.00 mewakili jam 03.00 - 06.00

Keterangan :

- Leq : Equivalent Continuous Noise Level atau Tingkat Kebisingan SinambungSetara ialah nilai tertentu kebisingan dari kebisingan yang berubah-ubah(fluktuatif selama waktu tertentu, yang setara dengan tingkat kebisingan darikebisingan yang ajeg (steady) pada selang waktu yang sama.Satuannya adalah dB (A).- LTMS = Leq dengan waktu sampling tiap 5 detik- LS = Leq selama siang hari- LM = Leq selama malam hari- LSM = Leq selama siang dan

malam hari.

2. Metode perhitungan:(dari contoh)

LS dihitung sebagai berikut :LS = 10 log 1/16 ( T1.10 01L5 +.... +T4.1001L5) dB (A)LM dihitung sebagai berikut :LM = 10 log 1/8 ( T5.10 01L5 +.... +T7.1001L5) dB (A)

Untuk mengetahui apakah tingkat kebisingan sudah melampaui tingkat kebisinganmaka perlu dicari nilai LSM dari pengukuran lapangan. LSM dihitung dari rumus :LSM = 10 log 1/24 ( 16.10 01L5 +.... +8.1001L5) dB (A)

3. Metode EvaluasiNilai LSM yang dihitung dibandingkan dengan nilai baku tingkat kebisingan yangditetapkan dengan toleransi +3 dB(A)

Jalur hijau sepanjang jalan kebun teh Wonosari

Foto: smno-malang-sept 2010

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Kebisingan didefinisikan sebagai "suara yang tak

dikehendaki, misalnya yang merintangi terdengarnya

suara-suara, musik dsb, atau yang menyebabkan rasa sakit atau yang menghalangi gaya

hidup.

Diantara pencemaran lingkungan yang lain,

pencemaran/polusi kebisingan dianggap istimewa dalam hal:

[1] Penilaian pribadi dan penilaian subyektif sangat

menentukan untuk mengenali suara sebagai pencemaran kebisingan atau tidak, dan

[2] Kerusakannya setempat dan sporadis dibandingkan dengan pencemaran air dan pencemaran udara (Bising pesawat udara merupakan

pengecualian). vancouver.ca/.../cclerk/970513/citynoisereport/

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Keluhan-keluhan tentang pencemaran di Jepang menurut jenisnya

Keluhan-keluhan tentang endapan tanah dihilangkan dari Tabel karena

sulit untuk menggambarkann

ya.

Sumber: Komisi Koordinasi Sengketa

Lingkungan

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Tiga Unsur dari Suara

Apabila keyboard dari piano ditekan, seseorang

menangkap "nyaringnya", "tingginya" dan "nada" suara yang dipancarkan. Ini adalah tolak ukur yang menyatakan

mutu sensorial dari suara dan dikenal sebagai "tiga unsur

dari suara".

Sebagai ukuran fisik dari "kenyaringan", ada amplitude

dan tingkat tekanan suara. Untuk "tingginya" suara

adalah frekwensi.

Tentang nada, ada sejumlah besar ukuran fisik,

kecenderungan jaman sekarang adalah

menggabungkan segala yang merupakan sifat dari suara,

termasuk tingginya, nyaringnya dan distribusi spektral sebagai "nada".

www.dosits.org/science/whatis/2.htm

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Frekwensi dan Panjang gelombang

Udara terdiri atas partikel-partikel yang beragam dimensinya. Semakit rapat partikel-partikel ini , tekanan udara semakin

bertambah; semakin jarang partikel-partikel , semakin rendah tekanan udara.

Gejala yang muncul akibat perubahan tekanan ini disebut sebagai gelombang suara. Suatu gelombang suara memancar dengan kecepatan suara dengan gerakan seperti gelombang.

Jarak antara dua titik geografis (yaitu dua titik di antara tekanan suara maksimum dan suara murni ) yang dipisahkan hanya oleh satu periode dan yang menunjukkan tekanan suara yang sama dinamakan "gelombang suara", yang dinyatakan sebagai (m).

Apabila tekanan suara pada suatu titik berubah secara periodik, jumlah berapa kali naik-turunnya periodik ini berulang dalam satu detik dinamakan "frekwensi", yang dinyatakan sebagai f

(Hz). Suara-suara ber-frekwensi tinggi adalah suara tinggi, sedangkan

yang ber-frekwensi rendah adalah suara rendah. Hubungan antara kecepatan suara c (m/s), gelombang dan

frekwensi f dinyatakan :

c = f x

Panjang gelombang dari suara yang dapat didengar adalah beberapa sentimeter dan sekitar 20 m. Mutu suara, yang dipengaruhi oleh kasarnya permukaan-permukaan yang

memantulkan suara, tingginya pagar-pagar dan faktor-faktor lainnya, akan berbeda sebagai perbandingan dari panjang

gelombang terhadap dimensi obyek, karena itu masalahnya menjadi lebih rumit.

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Gelombang sinusoidal

How do you characterize sounds? If you had to describe a specific sound to a friend, what words

would you use? If you can't think of any words, close your eyes and

listen to the people around you talk. Are you able to tell who is talking without opening your

eyes? How? What are the differences between the sounds

that different people make?Perhaps you thought of describing

a sound with the words loud or soft; high-pitched or low-pitched.

These words describe, or characterize, how we perceive

sounds. Scientists, on the other hand, describe sounds with characteristics that can be

measured using instruments. We can relate characteristics that

scientists measure to the words we use to describe the sounds we hear. When we talk about loud or

soft, scientists talk about the intensity, or amplitude, of the

sound. When we talk about the pitch of a sound, scientists use the

word frequency.


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Garis bentuk Kenyaringan

Intensity or Loudness Sound travels in a wave. The wave's amplitude is the change in pressure

as the sound wave passes by. If you

increase the amplitude of a sound, you are

making it louder, just as you do when you turn up

the volume on your radio. If you decrease the amplitude, you are

making the sound softer (turning down the

volume). Characteristics that

scientists use to describe sound, such as

amplitude, can be related to a picture of a

wave.


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Garis bentuk Kenyaringan

Dikatakan bahwa batas perbedaan suara yang bisa terdengar oleh rata-rata orang adalah 20 - 20,000 Hz, tetapi

bisa terdengarnya tersebut tergantung pada frekwensi. Tes-tes (hearing) psikiatris menghasilkan Garis bentuk

Kenyaringan .

Kurva menggunakan 1000 Hz dan 40 dB sebagai referensi untuk suara murni dan mem-plot suara referensi ini

dengan tingkat-tingkat yang bisa terdengar dari kenyaringan yang sama pada berbagai frekwensi.

Kenyaringan suara yang diterima oleh telinga manusia bervariasi karena dua sifat-sifat fisik yaitu tingkat tekanan

suara dan frekwensi. Bahkan dalam lingkup yang bisa terdengar, frekwensi-frekwensi rendah dan tinggi sulit

untuk ditangkap. Dibutuhkan kepekaan tinggi pada lingkup 1 - 5 kHz.

Apabila tingkat kenyaringan dari suatu suara dikurangi, pada suatu titik tertentu, suara tidak lagi terdengar. Tingkat

ini juga berbeda sesuai dengan frekwensi. Tingkat ini diindikasikan sebagai tingkat minimum yang bisa

terdengar (garis titik-titik) .

Tingkat minimum yang bisa terdengar pada 20 dB atau lebih dipandang sebagai kesulitan pendengaran.

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Pengaruh / Akibat-akibat dari Kebisingan

Apabila suatu suara mengganggu orang yang

sedang membaca atau mendengarkan musik, maka suara itu adalah kebisingan

bagi orang itu meskipun orang-orang lain mungkin tidak terganggu oleh suara

tersebut.

Meskipun pengaruh suara banyak kaitannya dengan

faktor-faktor psikologis dan emosional, ada kasus-kasus di mana akibat-akibat serius

seperti kehilangan pendengaran terjadi karena

tingginya tingkat kenyaringan suara pada

tingkat tekanan suara berbobot A atau karena

lamanya telinga terpasang terhadap kebisingan tsb.

Noise health effects are the health consequences of elevated sound levels.

Elevated workplace or other noise can cause hearing

impairment, hypertension, ischemic heart disease,

annoyance, sleep disturbance, and decreased

school performance.

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Jenis-jenis dari Akibat-akibat kebisingan

Tipe Uraian

Akibat-akibat badaniah

Kehilangan pendengaran

Perubahan ambang batas sementara akibat kebisingan, Perubahan ambang batas permanen akibat kebisingan.

Akibat-akibat fisiologis

Rasa tidak nyaman atau stres meningkat, tekanan darah meningkat, sakit kepala, bunyi dering

Akibat-akibat psikologis

Gangguan emosiona

Kejengkelan, kebingungan

Gangguan gaya hidup

Gangguan tidur atau istirahat, hilang konsentrasi waktu bekerja, membaca dsb.

Gangguan pendengaran

Merintangi kemampuan mendengarkann TV, radio, percakapan, telpon dsb.

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Tipe-Tipe Kebisingan

Jumlah kebisingan

Semua kebisingan di suatu tempat tertentu dan suatu waktu tertentu.

Kebisingan spesifik

Kebisingan di antara jumlah kebisingan yang dapat dengan jelas dibedakan untuk alasan-alasan akustik. Seringkali sumber kebisingan dapat diidentifikasikan.

Kebisingan residua

Kebisingan yang tertinggal sesudah penghapusan seluruh kebisingan spesifik dari jumlah kebisingan di suatu tempat tertentu dan suatu waktu tertentu.

Kebisingan latar belakang

Semua kebisingan lainnya ketika memusatkan perhatian pada suatu kebisingan tertentu. Penting untuk membedakan antara kebisingan residual dengan kebisingan latar belakang.

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Suara adalah gejala di mana partikel-partikel di udara bergetar dan menyebabkan perubahan-

perubahan dalam tekanan udara, karena itu intensitasnya dinyatakan sebagai tekanan suara. (Pascal adalah suatu unit [Pa]) dan energi yang

diperlukan untuk getaran (juga dinamakan "tenaga suara dari sumber ", unit-unit watt [W]). Bila

dinyatakan dalam Pascal, intensitas dari suara dinamakan "tekanan suara" dan menggunakan suatu unit referensi dari 20 Pa. Ini hampir sama dengan tekanan suara dari suara minimum yang

ditangkap oleh telinga manusia. Tingkat tekanan suara didefinisikan sebagai 10x

logaritma rasio dari tekanan suara efektif pangkat dua terhadap tekanan suara referensi efektif (20

Pa), dan dinyatakan dengan formula di bawah ini. Pendekatan ini diterima demi mudahnya anotasi, seperti - misalnya - suatu suara dengan 100 dB

akan mempunyai tekanan suara sebesar 100.000 kali tekanan suara referensi dengan seterusnya

menjadi terdiri dari banyak digit. Unit-unit itu adalah decibel (dB).

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www.co.san-juan.wa.us/.../scenicrdmanual.aspx

When planting the roadside, it is

important to relate the arrangement and location of plants to the natural patterns

of existing vegetation. The

following guides will be helpful to achieve

compatible relationships:

1. Plants should not be planted in

geometric or uniform patterns, nor

randomly scattered in a meaningless

pattern.

2. Plants should be informally grouped in masses and clumps, with attention given

to combinations which will provide

diversity and contrast.

3. Space trees so when mature they will

be proportional in size with surrounding

vegetation.

4. Arrange plants so their edge is uneven

and closer to the roadside in some

locations and further away in others.

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Demikian pula, intensitas suara didefinisikan secara kwantitatif sebagai tingkat kekuatan suara karena kekuatan suara dari unit-unit sumber (10 -

12 W). Seperti halnya dengan tingkat tekanan suara, unit-unit di sini menggunakan decibel.

Dalam menilai kenyaringan suara, perlu mempertimbangkan perbedaan cara bagaimana

suara ditangkap karena frekwensi, seperti dijelaskan dalam 1.4.

Untuk itu, alat-alat ukur tingkat kebisingan menggunakan rangkaian penyesuaian frekwensi

yang meng-asimilasikan kepekaan telinga manusia terhadap kenyaringan.

Karakteristik penyesuaian frekwensi umumnya digunakan karakteristik A.

Tingkat kenyaringan yang didapat sesudah penyesuaian frekwensi ini dinamakan "Tingkat

tekanan suara berbobot A (tingkat kebisingan)".

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Karakteristik frekwensi dari alat-alat ukur tingkat Kebisingan

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Tingkat percentile (LAN, T)

Kenyaringan kebisingan fluktuasi dengan waktu, karena itu perlu mempertimbangkan fluktuasi selama satu periode waktu ketika menilai tingkat tekanan suara

berbobot A. Dua indeks populer adalah tingkat percentile dan tingkat tekanan suara berbobot A yang

sepadan dan kontinyu.

Tingkat kebisingan yang, untuk N% periode dari waktu yang diukur, sama atau lebih besar dari tingkat tertentu,

dinamakan "Tingkat percentile N-persen". Variabel ini dinyatakan sebagai LAN dan suatu tingkat 50% (LA50)

diambil sebagai titik tengah, 5% (LA5) sebagai batas atas dari lingkup 90% dan 95% (LA95) sebagai batas bawah

dari lingkup 90% yang sama.

Dalam pengukuran yang menggunakan faktor waktu aktual, praktek pada umumnya adalah mengambil

contoh tingkat tekanan suara berbobot A pada interval waktu yang konstan, peroleh distribusi frekwensi

kumulatifnya, kemudian mendapatkan tingkat percentile spesifik. Pada umumnya, dalam penilaian kebisingan

lingkungan, sebaiknya mengambil 50 atau lebih contoh pada interval 5 detik atau kurang.

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Tingkat tekanan suara berbobot A yang sepadan dan kontinyu-(LAeq)

Tingkat tekanan suara berbobot A yang sepadan dan kontinyu banyak dipakai di seputar dunia sebagai indeks

untuk kebisingan. Itu didefinisikan sebagai "tingkat tekanan suara berbobot A dari kebisingan yang fluktuasi selama suatu periode waktu T, yang dinyatakan sebagai

jumlah energi rata-rata".

Itu dinyatakan dengan formula di bawah ini

P0: Tekanan suara referensi (20 Pa) PA: Tekanan suara berbobot A (untuk waktu A) dari

kebisingan target (Pa)Periode waktu adalah dari waktu t1 sampai waktu t2,

sedangkan jumlah contoh-contoh tingkat tekanan suara berbobot A adalah n.

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Tingkat tekanan suara berbobot A yang sepadan dan kontinyu

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Tingkat Ekspos Terhadap Suara (LAE)

Tingkat ekspos terhadap suara digunakan untuk menyatakan kebisingan satu kali atau kebisingan

sebentar-sebentar dalam jangka waktu pendek dan kontinyu. Variabel mengubah jumlah energi dari

kebisingan satu kali menjadi tingkat tekanan suara berbobot A dari kebisingan tetap 1-detik yang kontinyu

dari energi sepadan.Karena kebisingan kereta api dapat dianggap sebentar-sebentar, "kebijakan untuk mengatasi kebisingan dalam penambahan atau penyempurnaan jalur kereta api dalam

skala besar (Jawatan Lingkungan Jepang, Des. 1995)" adalah dengan mengukur tingkat ekspos terhadap suara

dari setiap kereta api yang lewat dan mendapatkan tingkat tekanan suara berbobot A yang sepadan dan

kontinyu .

T0: Waktu referensi (1 detik) t1 - t2: Waktu yang diperlukan untuk lewatnya satu

kereta api

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Tingkat Ekspos Terhadap Suara

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Formula untuk mendapatkan tingkat tekanan suara berbobot A yang sepadan dan kontinyu - dari tingkat

peng-eksposan suara dari setiap kereta api yang lewat adalah sbb:

T: Waktu (detik) yang ditargetkan untuk LAeq. Dari jam 07:00 sampai dengan 22:00 adalah 54,000 detik. Dari jam

22:00 sampai dengan 07:00 adalah 32,400 detik.

Tingkat kekuatan sepadan juga dapat dicapai dengan menggunakan kekuatan rata-rata dari suatu tingkat

ekspos terhadap suara (LAE) dan jumlah n kereta api sebagai berikut:

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Tingkat Kebisingan Terbobot yang Diterima secara Sepadan dan Kontinyu

(WECPNL, Jepang)

Tingkat Kebisingan Terbobot yang Diterima secara Sepadan dan Kontinyu (WECPNL) adalah suatu ukuran

yang diusulkan oleh organisasi penerbangan sipil Internasional (ICAO)untuk menilai ekspos yang kontinyu

terhadap kebisingan jangka panjang dari berbagai pesawat terbang. Perhitungannya rumit, tetapi WECPNL

yang digunakan untuk peraturan lingkungan hidup di Jepang didefinisikan dengan formula yang

disederhanakan sbb:

LA: Kekuatan rata-rata dari tingkat-tingkat tinggi kebisingan pesawat 10 dB atau jauh lebih besar dari

kebisingan latar belakang.N: Jumlah pesawat yang berangkat tiap jam.

N1: 24:00 - 07:00, N2: 07:00 - 19:00, N3: 19:00 - 22:00, N4: 22:00 - 24:00

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Propagasi Suara (Rambatan Suara)Kekuatan suara dari sumber dan Tingkat Kekuatan

Suara

Suara dipancarkan apabila suatu sumber bergetar, tetapi kenyaringan dari suara yang dipancarkan

berubah tergantung pada intensitas dari sumber. Intensitas ini didefinisikan sebagai energi suara yang dipancarkan dari sumber dalam 1 detik dan

dinamakan "kekuatan suara dari sumber (P)" (unit-unit dari watts [W]).

Tingkat indikasi untuk intensitas dari kekuatan suara ini dinamakan "tingkat kekuatan suara

(PWL)". Seperti terpampang dalam 2.1, tingkat kekuatan suara sama dengan tingkat tekanan suara. Tetapi, di mana tingkat tekanan suara

mengekspresikan kenyaringan suara yng dimonitor dalam suatu titik sembarangan, tingkat kekuatan suara mengekspresikan intensitas dari kekuatan akustik yang dipancarkan oleh suatu

sumber.

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Propagasi Suara

Pada suatu titik berjarak r meter dari sumber suara sederhana, hubungan antara tingkat kekuatan suara

(dB), tingkat intensitas suara IL (dB) dan tingkat tekanan suara SPL (dB) adalah sbb.

SPL=IL=PWL - 20log r- 11 (Lapangan bebas)SPL=IL=PWL - 20log r- 8 (Lapangan setengah bebas)

Yang dimaksudkan disini ialah bahwa, apabila tingkat kekuatan suara tidak dapat diukur secara langsung,

tingkat kekuatan suara dari sumber dapat diperkirakan dari tingkat tekanan suara yang diukur pada suatu titik

yang jauh dari sumber.

Itu juga merupakan formula dasar yang digunakan secara terbalik untuk meramalkan kenyaringan dari

suara yang menyebar ke dalam lingkungan, dari tingkat kekuatan suara.

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PENGARUH DAN AKIBAT DARI KEBISINGANMeskipun pengaruh suara banyak kaitannya dengan

faktor-faktor psikologis dan emosional, ada kasus-kasus dimana akibat-akibat serius seperti kehilangan pendengaran terjadi karena tingginya tingkat

kenyaringan suara pada tingkat tekanan suara berbobot A dan karena lamanya telinga terpajan terhadap

kebisingan itu. Berikut jenis dari akibat kebisingan :

Tipe Uraian

Akibat

lahiriah

Kehilangan

pendengaran

Perubahan ambang batas sementara

akibat kebisingan, perubahan ambang

batas permanen akibat kebisingan

Akibat fisiologi

s

Rasa tidak nyaman atau stress meningkat,

tekanan darah meningkat, sakit

kepala, bunyi dering

Akibat

psikologis

Gangguan

emosional

Kejengkelan, kebingungan

Gangguan

gaya hidup

Gangguan tidur atau istirahat,

hilang konsentrasi waktu bekerja, membaca dan sebagainya.

Gangguan

pendengaran

Merintangi kemampuan

mendengarkan TV, radio, percakapan,

telpon dan sebagainya.

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Decibels

Decibel (dB) adalah kwantitas logaritmis yang dipakai sebagai unit-unit

tingkat tekanan suara berbobot A. Ini dilakukan

untuk dua alasan: pertama untuk menyederhanakan plot-plot multipel , ke dua

untuk secara kira-kira menyebandingkan

kwantitas logaritmik dari stimulus untuk stimulus

akustik yang diterima telinga manusia dari luar.

Untuk menilai kebisingan, perlu untuk menghitung

tambahnya atau kurangnya tingkat tekanan suara

berbobot A rata-ratanya dan sebagainya.

Ini memerlukan pengetahuan dasar tentang perhitungan

logaritma.

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Highway Traffic Noise

In recent years, highway traffic noise -

the unpleasant, unwanted sounds generated on our

nation's streets and highways - has been of

increasing concern both to the public and to local, National and regional officials. At the same time,

modern acoustical technology has been

providing better ways to lessen the adverse impacts of highway

traffic noise. Some of acoustical techniques are now being employed by

government agencies, highway planners and

designers, construction engineers, and private

developers.

www.wsdot.wa.gov/.../commonquestion

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NOISE REDUCTION

www.nonoise.org/.../highway/traffic/traffic.htm

Vegetation, if it is high enough, wide enough, and dense enough that

it cannot be seen through, can decrease highway traffic noise.

A 200-foot width of dense vegetation can

reduce noise by 10 decibels, which cuts in

half the loudness of traffic noise.

It is often impractical, however, to plant

enough vegetation along a road to achieve such

reductions. But, if dense vegetation

already exists, it could be saved. If it does not

exist, roadside vegetation can be planted to create a

psychological relief, if not an actual

lessening of traffic noise levels.

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Sound and NoiseAs we all know, sound is created when an object

moves: the rustling of leaves as the wind blows, the air passing through our vocal chords, the almost

invisible movement of the speakers on a stereo. The movements cause vibrations of the molecules in air in waves like ripples on water. When the vibrations

reach our ears, we hear what we call sound.

Sound is quantified by a meter which measures units called decibels (dB). For highway traffic noise, an

adjustment, or weighting, of the high- and low-pitched sounds is made to approximate the way that

an average person hears sounds. The adjusted sounds are called "A-weighted levels"(dBA).

The A-weighted decibel scale begins at zero. This represents the faintest sound that can be heard by humans with very good hearing. The loudness of sounds (that is, how loud they seem to humans)

varies from person to person, so there is no precise definition of loudness. However, based on many tests

of large numbers of people, a sound level of 70 is twice as loud to the listener as a level of 60.

35

www.csc.noaa.gov/.../gulfmex/html/rsdetail.htm

36

To achieve a reduction in noise emissions the

Agency is:

Ensuring that when a road needs a new surface, the most appropriate noise

reducing surfaces are used where noise is a particular concern.

Specifying quieter surfaces as a matter of

course where new roads are to be built or existing

roads improved.

Identifying sites for the provision of noise

mitigation such as noise barriers and double-glazing. Researching

tyre/road noise in partnership with vehicle standard authorities and

the tyre industry.

Working towards improved performance in

noise control during construction/maintenanc

e activities. www.highways.gov.uk/aboutus/10850.htm

37

Causes of Traffic NoiseThe level of highway traffic noise depends on three things: (1) the volume of the traffic, (2) the speed of

the traffic, and (3) the number of trucks in the flow of the traffic. Generally, the loudness of traffic noise is increased by heavier traffic volumes, higher speeds,

and greater numbers of trucks.

Vehicle noise is a combination of the noises produced by the engine, exhaust, and tires. The

loudness of traffic noise can also be increased by defective mufflers or other faulty equipment on

vehicles. Any condition (such as a steep incline) that causes heavy laboring of motor vehicle engines will also increase traffic noise levels. In addition, there are other more complicated factors that affect the

loudness of traffic noise.

For example, as a person moves away from a highway, traffic noise levels are reduced by distance,

terrain, vegetation, and natural and manmade obstacles. Traffic noise is not usually a serious

problem for people who live more the.500 feet from heavily traveled freeways or more than l00 to 200 feet

from lightly traveled roads.

38

How Traffic Volume Affects Noise

A

2000 vehicles per hour

B

200 vehicles per hourA sounds twice as loud as B.

How Speed Affects Traffic NoiseA

55 miles per hour

B

15 miles per hour

A sounds twice as loud as B.

Aneka kendaraan bermotor jalan raya

Determining noise Impact

Highway traffic noise is never constant. The noise level is always changing with the number, type, and speed of the

vehicles which produce the noise. Traffic noise variations can be plotted, as shown by the

graph below. It is usually inconvenient and cumbersome to use such a graph to represent traffic noise in this manner. A more practical method is to convert the noise data to a

single representative number.Statistical descriptors are almost always used as a single

number to describe varying traffic noise levels. The two most common statistical descriptors used for traffic noise are L10 and Leq. L10 is the sound level that is exceeded 10 percent

of the time.

41

www.earthworksaction.org/noiseresources.cfm

How Sound TravelsSound is caused by changes in air pressure. For example, when a mallet strikes a drum the drumhead begins to move back and forth (vibrate). As the drumhead moves down, air is pulled toward it, and

as the head bounces back up it pushes air away. This creates changes in air pressure that move (or propagate) away from the

drum, eventually striking our eardrum. These changes in pressure are known as sound waves.

There are a number of factors that affect the propagation of sound. The most important include: distance from source; obstacles such as barriers and buildings; atmospheric absorption;wind direction

and speed; temperature and temperature gradient; humidity; precipitation;reflections; and ground absorption.

It is important to understand that noise does not always decrease as one moves away from a noise source. The above factors can work to increase or decrease noise levels. For example, at short distances (up to 160 feet) the wind has a minor influence on the

measured sound level.

At distances greater than 1,000 feet from a noise source, noise can become louder on the downwind side by as much as 20 dB, while on the upwind side levels can drop by 20 dB (depending on wind

speed and distance).

Other things to consider include the fact that while barriers may act to reduce high frequency sounds, low frequency sounds are

difficult to reduce using obstacles or barriers. Additionally, while soft ground surfaces and the atmosphere are effective at absorbing mid-frequency and high frequency noise, these factors do not tend to reduce low frequency noise to the same degree. This means that as one moves away from the source, low frequencies often become

much more prominent.

43

Noise Compatible Reduction Techniques - Physical Responses Topography

Sound waves are affected by the terrain - whether hilly or flat - between the source and the receiver. A berm or hill will block sound and diminish its intensity. A ditch or gulley deflects the sound and

depending on its depth and dimension will diminish the sound and/or cause a change in its path. Where hills are available, constructing

noise sensitive uses behind the hills helps reduce sound problems.

www.fhwa.dot.gov/.../noise/ncp/ncp_curr.htm

Taman untuk meredam kebisingan

The Surface"Propagation medium" describes the area between the sound source and the receiver, including the type of ground surface

(Exhibit 2). For instance, a fence reflects or deflects sound according to its height, thickness and material. Sound is affected

by the type of surface, as well. Porous surfaces, like dirt or grass, absorb some sound; surfaces not so porous, like asphalt or concrete, will reflect some sound affecting how it's heard by

the human ear.

45

www.avtreefarm.com/files/sound-barrier.htm

Planting a Sound Barrier

Vegetation can be used to barrier the

effects many problems including

noise pollution.

As with plantings for wind or visual barriers, the

selection and arrangement of the plant material is key

to a successful outcome.

46

Planting a Sound Barrier

Noise reduction is achieved by either deflection or absorption of the noise or a combination of the two. Most hardscape barriers work by deflecting sound

(example 1in pic.).

To be effective they should be close to the source of the noise as safety allows. With these barriers vegetation

serves to soften the visual effect of the barrier and reduce the reverberation of sound. Earthen berms are

often used in combination with trees and shrubs to deflect and absorb sound when the available space is

limited.

Vegetation alone can be used where adequate space is available. To be effective the planting must be multiple

rows to about 40‑75' in depth. Care also must be taken to plant the first row at 50' from a roadway or any area‑ that

should not be subject to extra snow deposits.

Conifers or evergreen broadleaf plants will naturally provide the best year around noise reduction.

Deciduous trees and shrubs can be added to the planting for variety and added summer noise reduction

47

PEMILIHAN VEGETASI

Vegetation should be selected for site conditions with special attention to plant selection guidelines section. It is also important to incorporate fast growing plants and long

lived plants for a quick and long lasting barrier. Shrubs: Plant in rows closest to the sound.

Chose dense or thicket forming shrubs that tolerate salt or deicing chemicals and air pollutants.

Caragana arborescens ; Philadelphus spp.; Potentilla fruticosa; Symphoricarpos spp.

Conifers: Trees that retain lower branches will be most effective.

Abies concolor; Juniperus spp.

Barisan pepohonan di sepanjang jalan yang sunyi

Foto: smno-malang-okt 2010

Deciduous trees: Taller trees should be selected for the center of the vegetative barrier. Fast growth rate can be considered to provide a more effective barrier more quickly. Smaller trees especially those

with attractive flowering and form work well on the inside of the barrier for both visual and sound effect.

Acer platanoides Acer saccharinum

Aesculus hippocastanum Eleagnus angustifolium

Fraxinus americana Gleditsia triacanthos and its varieties

Juglans nigra

Malus species (for inside rows as flowering sensitive to high levels of air pollutants)

Populus spp.Prunus spp.

Robinia pseudoacacia Salix spp.

www.for.gov.bc.ca/.../HEALTH/GFHS0004.HTM

www.syllent.com/media.html

www.daviddarling.info/encyclopedia/N/noise.html

Concrete barriers and vegetation

The engineering of these walls acoustic absorbents basa composción in the walls of two modules in which concrete is introduced along with the vegetation and

topsoil must retainer of water to provide moisture

Between the two there is an air chamber which further contributes to the sound insulation required.

www.metrolight-es.com/eng_catalogo-barreras-a...

Wooden barriers

Protective barrier against the noise produced in Nordic wood Thanks to the perfect acoustic isolation enclosure for tight

joints

Extensive range of finishes as the final position of the front panels There is also another kind of anti screens

manufactured in wood (logs) This is a double-walled enclosures housing land in the interior.

www.metrolight-es.com/eng_catalogo-barreras-a...

Purpose of Noise Compatible Land Use Planning (NCP)

Commercial, Office, Retail, or Industrial UsesCommercial, office, retail or industrial uses next to highways

experience improved accessibility and appreciate easy access to transportation arteries. Visibility is better for

customers and deliveries, as well. These land uses are not negatively affected by the noise and they can serve to buffer residential or other sensitive uses from roadway generated

sound. Vegetation may be planted to further buffer commercial uses from residential areas. Exhibits 1 and 2

show examples of commercial and other uses next to roadways.


Open Space

Community planners should actively seek opportunities to reserve undeveloped land and open space in locations where

future roadways may be constructed.

Open space allows sound to diminish before reaching sensitive receivers. Open space strategies may be used in

combination with other strategies including commercial uses or noise reducing construction methods for buildings.

Walking and bike paths and other recreational activities are options in the open space.


DistanceThe greater the distance between the source of the sound and the receiver, the lower the noise level.

Distance can be achieved by providing open space, as with recreational uses or publicly owned property that

creates a buffer (such as state right-of-way). Local ordinances can require "setbacks," which

mandate the locations for the front line of buildings. Setbacks reduce the impact of traffic noise if they are

sited so as to allow enough space between the roadway and the receiver for sound to dissipate to

acceptable levels


55

Effect of roadside vegetation on the reduction of

traffic noise levelsC.M. Kalansuriya1, A.S. Pannila1, D.U.J Sonnadara2

1Electro Technology Laboratory, Industrial Technology Institute2Centre for Instrument Development, Department of Physics, University

of Colombo

A study was carried out to determine the effect of roadside vegetation on the reduction of road traffic noise

levels under varying traffic conditions. Roadside vegetation which have the potential to act as noise

barriers were selected for this study. The road traffic noise was measured together with the parameters that control the vegetation. Several noise level descriptors

were recorded together with the A-weighted continuous noise level.

The results show that higher frequency noise (above 4 kHz) is heavily attenuated by the vegetation barriers with virtually no attenuation for low frequency noise (below 100 Hz). The width of the vegetation barrier is linearly

proportional to the amount of sound absorption. Without the vegetation barrier, the observed maximum and minimum noise levels were 72 dB(A) and 64 dB(A)

respectively. On average, vegetation barriers were able to reduce the noise by 4 dB(A) which corresponds to an

approximately 40% acoustic energy reduction. Thus, with careful planning and growing of roadside vegetation, the

effect of road noise can be reduced.

BARIER VEGETASIVegetation barriers were able to reduce the noise by 4 dB(A) which corresponds to an approximately 58% acoustic energy reduction.

The measurements clearly show that higher frequency noise is heavily attenuated by the vegetation barrier and virtually no

attenuation of low frequency noise. The noise absorption is linearly proportional to the width of the

vegetation barrier. In order to achieve higher absorption of 5 dBA or better, width of the vegetation barrier must be at least 1.5 meters

thick. No clear dependency on the height of the vegetation barrier. Data shows that most of the high noise values are in the mid

frequency range where 4 dB(A) or above absorption rates due to vegetation barriers were observed.

Vegetasi pepohonan rindang untuk meredam kebisingan

NATURAL VEGETATION

Natural vegetation, if high enough, wide enough, and dense enough, can decrease

roadway traffic noise. Vegetation plant noise barrier are environmental friendly,

having natural appearance and often pleasant in visually inspection. The effectiveness in

screening depends on the thicknesses of vegetation belts along the roadways and density of leaves (type of vegetation). Effective

noise barriers can reduce noise levels by 10 to 15 decibels. However, the degree of difficulty increases with the level of

reduction .

Proceedings of the Technical Sessions, 25 (2009) 1-6. Institute of Physics – Sri Lanka

JALUR VEGETASI JALAN RAYA.

Noise absorption for range of frequencies.

www.ecy.wa.gov/programs/sea/pubs/93-31/faq.html

Variation of noise absorption with the vegetation barrier width.

speclab.cr.usgs.gov/PAPERS.calibration.tutorial/

Noise absorption with vegetation barrier height

www.ecy.wa.gov/programs/sea/pubs/93-31/faq.html

62

Road noise with and without vegetation barrier

www.ciesin.org/docs/005-477/005-477.html

63

Mitigation of Traffic Noise

“A traffic noise impact occurs when the predicted levels approach or exceed the noise abatement criteria (NAC)

or when predicated traffic noise levels substantially exceed the existing noise level, even though the

predicted levels may not exceed the NAC.”

Federal Rule – Highway Traffic Noise Analysis & Abatement Policy & GuidanceFHWA – June 1996 (23 CFR 772)

64

The Use of Vegetation for Noise Reduction

The following excerpt from the federal regulation cited above and drawing explain the limitations of

using vegetation for noise mitigation:

Vegetation

Vegetation, if it is high enough, wide enough, and dense enough that it cannot be seen through, can

decrease highway traffic noise. A 61‑meter width of dense vegetation can reduce noise by 10 decibels, which cuts in half the loudness of traffic noise. It is

usually impossible, however, to plant enough vegetation along a road to achieve such

reductions.

Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz

JALUR HIJAU JALAN RAYA

Roadside vegetation can be planted to create a psychological relief, if not an actual lessening of traffic

noise levels. Since a substantial noise reduction cannot be obtained for an extended period of time, the FHWA does not consider the planting of vegetation to

be a noise abatement measure.

The planting of trees and shrubs provides only psychological benefits and may be provided for visual, privacy, or aesthetic treatment, not noise abatement.


KEBISINGAN LALU-LINTASTraffic noises produced by trucks, cars, and city buses were

recorded on magnetic tape to provide the sound source. These prerecorded sounds were played back through tree

and shrub barriers, and the sound level was measured behind the barriers at varying distances.

This procedure was repeated at nearby locations, but without the trees, to evaluate the effectiveness of trees in reducing

the noise level.


www.burnley.gov.uk/site/scripts/documents_inf...

The potential value of vegetation as noise abaters, as determined by the study, was deemed very good.

Findings showed that reduction of sound values in the order of 5 to 10 decibels are not unusual for wide belts of tall, dense trees.

Species did not appear to differ greatly in their ability to reduce noise levels, provided the deciduous varieties were in full leaf. However,

evergreens are favored for year-round noise screening. A supplementary study of various surfaces indicated that, from a noise-reduction standpoint, surfaces covered with trees were the

best.

www.highways.gov.uk/roads/projects/11064.htm

Screening of urban residential property was effective with a single row of dense shrubs backed by a row of

taller trees, totaling a depth of 20 feet.

Screening for rural areas or freeways where truck traffic is heavy requires wider belts consisting of

several rows of tall trees in dense plantings.

Distances of 100 feet or more between the noise source and the area to be protected were found

desirable.


egov.cityofchicago.org/chicagotrees/forest.html

69

Recommendations arising from the study that may be applied to some current noise problems include:

—To reduce noise from high-speed car and truck traffic in rural areas, plant 65- to 100-foot-wide belts of trees and shrubs, with

the edge of the belt within 50 to 80 feet of the center of the nearest traffic lane. Center trees should be at least 45 feet tall.

Consult local nurserymen and landscape architects for specific varieties at a given locality.

—To reduce noise from moderate-speed car traffic in urban areas where the interaction of tires and roadway is the principal

cause of noise, plant 20- to 50-foot-wide belts of trees and shrubs, with the edge of the belt from 20 to 50 feet from the

center of the nearest traffic lane. Use shrubs 6 to 8 feet tall next to the traffic lane, with backup rows of trees 15 to 30 feet tall.

—For best results, trees and shrubs should be planted close to the noise source rather than to the area that needs protection. —Where possible, use taller varieties of trees that have dense foliage and relatively uniform vertical foliage distribution, or combinations of shorter shrubs and taller trees to give this

effect. Where the use of tall trees is restricted, use combinations of shorter shrubs and tall grass or similar soft ground cover in preference to paved, crushed rock, or gravel

surfaces. —Trees and shrubs should be planted as close together as practical to form a continuous, dense barrier. The spacing should conform to the established local practices for each

species. —Where year-round noise screening is desired, evergreens or deciduous varieties that retain their leaves throughout most of

the year are recommended. —The planted belt should be approximately twice as long as the distance from the noise source to the receiver. When used as a

noise screen parallel to a roadway, it should extend equal distances along the roadway on both sides of the protected

area.

Screening is most effective when trees and shrubs are combined with soft rather than hard surfaces, such as pavement or gravel. This can result in a 50

percent or more reduction in the apparent noise.

Certain natural and practical considerations limit the use of trees and shrubs as noise screens. Due to the physical nature of sound and the extreme

sensitivity of the human ear, sound cannot be brought below the threshold of hearing, no matter how extensive the natural vegetation. Very thinly planted trees, or trees in poor condition as a result of neglect or of an unfavorable

growth environment, offer little resistance to the passage of sound. Ground forms are frequently limiting, as when elevated highways are above the

treetops so that there is relatively minor sound absorption from below. Also, a right-of-way or land use requirements may prevent an effective noise

screening, especially where belts of 75- to 100-foot widths are needed.


www.travel-images.com/photo-lord-howe7.html

General requirements for developments that include sensitive receiving environments :

Buildings are designed and constructed to reduce the intrusion of noise,

by locating rooms most sensitive to noise such as those for sleeping, relaxation or study,

furthest from existing and potential noise sources.

www.earthworksaction.org/noiseresources.cfm

Noise Control in the Built Environment

The most intensive exploration of new technologies for transportation noise control is in sound barrier. The effective noise

barriers can reduce noise levels by 10 to 15 decibels, cutting the loudness of traffic noise in half.

This is often true initially. However, a common problem arises when

the abatement effect "wears off" over time, leading to renewed community complaints. The noise barriers seldom achieve 10 dB of

noise reduction, and typically achieve about one-half that much. The barriers are designed for ground floors only; upper floors

receive little or no benefit. The reduction is heard only by the residents closest to the wall. The

benefits are variable .

74


Current techniques in use include:

Noise and Sound Walls:

Built of wood, stucco, concrete, masonry, metal and other materials, these walls have limitations.

They must be high enough and long enough to block the view of a road (although not generally higher than 25 feet, for structural and aesthetic

reasons); and they often do little for hillside homes above the road.

Openings for driveways or intersecting streets will destroy the effectiveness of a sound wall.

75


Earth Berms: Formed from earth mounds and walls (and more

attractive than sound walls) earth berms can require considerable land to build, especially when

they are high.

Freeway Lids: Noise mitigation can be a tremendous secondary

benefit of freeway lids. This solution is very expensive, however, and may

not compete well with other needs for scarce transportation funding.

Low-Noise Pavement: Still in experimental use, low-noise pavement is

currently being researched. (A test patch was in place on I-5, between Seattle

and Tacoma).

Because the pavement has a tendency to break up under heavy use and can lose its special ability

over time, its applications may be limited.

ArtCrete screen walls, perimeter fences, buffers and sound barriers. It provides total solutions for your specific sound barrier wall and decorative fencing

requirements. It is a multi-source company offering products from worldwide leaders in ornamental pre-

cast concrete systems. It offers a full line of products and services from site evaluation, initial design and

engineering through installation and customer support.

The ArtCrete Collection offers two different systems. LW The light weight, pre-engineered modular wall

system that uses interlocking panels and posts made of high performance glass fiber and steel reinforced pre-colored concrete panels and post. HD The heavy

duty, customized modular sound and sight wall system that is well suited for "Design-build."

77

Manajemen Kebisingan

78

Noise Management

In addressing land use and development, the location of and relationship between various land uses and the effects of land

use and development, including noise management issues, are required to be

considered.

The qualities of the acoustic environment are conducive to:

(a) the wellbeing of the community or a part of the community, including

its social and economic amenity;

(b) the wellbeing of an individual, including the individual opportunity to

have sleep, relaxation and conversation without unreasonable interference from intrusive noise.


The policy is to enhance or protect acoustic environmental values of through :

(a) incorporating noise levels for the local area;

(b) ensuring appropriate acoustic information is obtained at the

development assessment stage to assess impacts on the acoustic environmental

values.


General

This policy also seeks to provide clear guidance to those seeking development approval, regarding the assessment provisions for projects which either emit noise or introduce a sensitive receiving environment with the potential to be affected by a noise emitter.


Manajement Kebisingan

Noise can be defined as unwanted sound that unreasonably intrudes into our daily activities and can cause varying degrees of nuisance and annoyance.

Many sources of noise are often associated with urban development including road, air and rail transport,

industrial operations, neighbourhood and recreational pursuits, and agricultural activities.

Noise can affect human health and well-being. This can occur in a number of ways, including

annoyance reaction, sleep disturbance, interference with communication, performance effects, effects on

social behaviour, and hearing loss. If it is allowed to continue it may cause severe mental

stress. It can also cause very real physical problems such as

chronic exhaustion, high blood pressure and heart disease.

Noise that occurs at night is more likely to disturb a community than noise that occurs during the day.

Noise may contain annoying characteristics, such as : (a) tonality - humming and whining;

(b) modulation - regular changes in level or pitch such as a siren;

(c) impulsiveness - hammering.


A proposed development should not result in

significant deterioration of the existing acoustic environment.

The development of a sensitive receiving environment should not occur where existing noise sources would

result in the acoustic environment of this new development being unreasonably compromised.


Prior to lodging an application for a development an evaluation of the suitability of the proposal is conducted,

including a review of the constraints and opportunities for that development.

In doing this, at least the following is considered prior to finalising the proposal:

(a) location; (b) interaction with the surrounding environment, both

internal and external to the development.


In particular, the various types of land uses such as nearest noise emitters and/or sensitive receiving environments are

identified in the planning process. Prior to making an assessment an initial scoping

assessment is considered to determine the background noise levels of the surrounding environment.

This assessment should be representative of the operation of existing or proposed noise generating activities.

Information from this assessment would be valuable in determining the appropriateness of the development for that

location.


When considering the likely impact of a proposed development and the times when noise will be emitted

or received, it is also important to note whether the noise emissions are likely to contain annoying

characteristics. The different types of noise generating activities that need to be considered include : 1. Noise during construction phase; 2. Noise from normal plant operation; 3. Transport and traffic noise, including increased

traffic 4. Movements; 5. Behavioural noise; 6. Music and entertainment, both live and recorded; 7. Public address systems; 8. Noises normally associated with the conduct of a 9. Particular industrial or commercial use.


87

Other noise generating activities arising from within the development site should also be taken into

consideration at the planning phase. For example, locating residential backyards with pools and lounge rooms with sound systems away from bedrooms of

neighbouring houses.

Developments with mixed uses need to consider noise impacts on residential components or other noise sensitive environments of the development. When

considering noise attenuation measures, applicants should evaluate a range of acoustic treatments

available to achieve the required noise criteria.

Acoustic fencing is the least preferred noise attenuation measure and should only be used where

all other measures have been explored, or where necessary to supplement other measures.


88

It should be noted that, depending on the issues, officers from different areas within

council may need to be involved in the assessment of the noise component of a

development application. For example the range of issues for a noise assessment that are likely to require input from different areas within council are -

1. Acoustic performance issues; 2. Wildlife and vegetation issues; 3. Landscaping and safety issues; 4. Amenity issues; 5. Road access; 6. Structural requirements, design and

proposal layout issues; 7. Maintenance issues.


Noise control strategy : A clear and concise statement is required which sets out the proposed strategy or strategies to deal with each of the identified noise issues. This may include a combination of: a. Source control - such as plant selection; b. Source modification – such as acoustical treatments or management measures; c. Propagation control – such as buffers and barriers; d. Receptor modification – such as a dwelling upgrade.


(f) Control at the source: 1. Use of low-noise equipment such as refrigeration

condensers, packaged low-noise air compressors or generator sets;

2. Use of alternative, quieter technology, for example replacing sirens with flashing lights, using electric cranes in preference to diesel-powered cranes and using mobile phones or personal pagers instead of telephone extension bells;

3. Use of more appropriate control technologies such as variable speed drives on cooling tower fans or two-speed fans on air-cooled condensers in order to avoid stop/start operations and to reduce noise emission levels at night;

4. Use of carbon monoxide monitors to control fan operations in carpark exhaust systems, again matching fan performance to demand to effectively reduce noise emissions at night;

5. Use of solid-state switching in preference to relays; 6. Use of soft-start electric motors on drives which

require cyclic operation; 7. The report describes any recommended or proposed

low-noise plant. Where the make and model of specific plant selections can be identified, their noise performance is detailed in terms of their sound power levels or sound pressure levels at nominated distances. Where schematic or conceptual designs only are available, the typical performance and improvements are stated;


(g) Source modification:

This may include technical treatments such as acoustical enclosures around plant, or may rely on staff implementing appropriate procedures to minimise noise:

1. There are a number of firms specialising in noise control, offering both off the shelf and purpose-designed acoustical treatments. Such treatments have the potential to interfere with the performance and/or efficiency of plant operation. It is therefore recommended that specialist advice be sought in the planning and design of these measures;

2. The report describes the intended noise reduction measures and their anticipated performance;

3. Management measures include all noise control actions which rely on people to behave in a particular way. This may require delivery drivers to use a specific route or curtail particular activities such as the use of exhaust brakes. It may require staff to restrict certain activities to certain times or to intervene by closing doors or re-directing activities;

4. If management measures are proposed, a site-specific noise management plan is required. This plan should include at least one contingency action in the event that the primary noise plan fails to achieve or maintain the nominated outcome;


Propagation control includes the use of buffer zones and/or noise barriers to achieve noise

attenuation. The report shall include plans showing the

locations and heights of all noise sources, and the locations and heights of any proposed noise

barriers. Where buildings are relied on to provide barrier

screening, the elevations and locations of openings such as doors and windows are also

provided.


93

(i) Information on noise monitoring and/or noise predictions, modelling and results including:

(1) A description of the existing noise climate including :

a. Ambient noise levels during day, evening and night

b. Periods on both weekdays and weekends;

c. Prevailing atmospheric conditions.

(2) Location of monitoring sites and rationale for its Selection;

(3) Noise prediction results for when attenuation measures are provided and where no attenuation measures are provided;

(4) Details and assumptions used in the model for predictions;

(5) Criteria established for assessment purposes.


94

When including details of attenuation measures identified to achieve compliance with noise criteria, also provide the

methods used to calculate this attenuation.

For development of sensitive receiving environments adjacent to roads and railways, as identified in the Road and Rail Noise

Overlay :

(a) Describe the noise attenuation measures to be implemented to reduce traffic noise affecting the proposed

adjoining development. Noise nuisance should be ameliorated in the first instance through the design, orientation and layout of

the site. As stated earlier, to achieve the design level noise criteria it should be demonstrated that a range of acoustic

treatments available for application at the site were evaluated.


95

Design and layout for rooms sensitive to noise

96

Noise Management

For developments including a sensitive receiving environment adjacent to

roads and railways, the noise report should also include a suitably scaled

plan indicating the following :

(i) for road noise :

a. predicted 60 (or 63) dB(A) LA10 (18 hour or less)

contour with and without noise attenuation measures;

b. predicted 55 dB(A) LAeq (1hr) contour with and without

noise attenuation measures; c. the noise contours are plotted for

both lowset and two- storey dwellings. For dwellings, the

receptor height is taken to be 1.5 metres above each

finished floor level.

97

Noise Management

For developments including a sensitive receiving environment adjacent to roads and railways, the noise report should also include a suitably scaled plan indicating the following :

(ii) for rail noise :

a. predicted 87dBA LA max contour with and without noise attenuation measures; b. predicted 65 dB(A) LAeq (24 hour) contour with and without noise attenuation measures; c. predicted 55 dB(A) LAeq (1hr) contour with and without noise attenuation measures; d. the noise contours are plotted for both lowset and two- storey dwellings. For dwellings the receptor height is taken to be 1.5 metres above each finished floor level.

98

Noise Management

(iii) location of proposed barriers indicating heights of barriers and portion of land required to accommodate mounds, where applicable;

(iv) floor plan / layout of proposed development, where applicable;

(v) the noise measurement location and its rationale for selection;

(vi) calculations must indicate the attenuation provided by each alternative through distance, barrier, building and angle of exposure;

(vii) show cross sections of the design and proposed location of the acoustic barriers where not in compliance with the policy;

(viii) the option for the use of acoustic barriers is supported by an assessment of the public safety and visual amenity of the structures; (ix) provide indicative elevations of cross sections and plans to indicate that the barriers will fit on the site and that adequate park dedication is provided to fit the barrier.


1. Buildings are designed and constructed to reduce the intrusion of noise, by locating rooms most sensitive to noise such as those for sleeping, relaxation or study, furthest from existing and potential noise sources.

2. Buildings are constructed using materials including insulation and glazing materials with a high noise transmission loss.

3. Reduce the area covered by openings such as windows and doors that face existing and potential noise sources.

4. Provide mechanical ventilation to rooms most sensitive to noise such as those for sleeping, relaxation or study.


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Noise Management


Provide adequate setback or buffer distances between noise sources and the sensitive receiving environment :

(i) in providing setback or buffer distances between noise sources and sensitive receiving environments, site specific distances are calculated by a suitably qualified acoustic consultant. Issues including topography, climate and all current and predicted impacts from incompatible adjacent land uses, during day and night time periods, are considered in determining these buffer distances;

(ii) where buffer distances are incorporated within the lot or premises, sensitive receiving environments are indicated on proposal plans and are not located within the buffer.

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Noise Management


(f) Design, orientate and construct buildings to effectively screen external private open space areas from the noise source. (g) Use appropriate buffer distances between the noise source and external private open space areas. (h) Provide suitable noise attenuation barriers where needed. (i) Where requested, also provide noise monitoring information and/or noise prediction and modelling including noise assessment results, as previously outlined.

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Noise Reduction

Details are provided about the proposed noise control measures to be applied at the site, including the expected noise

reduction where the earlier assessment of predicted levels shows adverse local and

remote noise impact.

The scale of the improvements to be provided by the noise control measures is predicted to confirm compliance with the

appropriate criteria. For example, this could be demonstrated by providing

contour predictions on a site plan for each of the attenuation options.

If acceptable noise levels cannot be achieved, additional information is provided to justify approval of the

development.

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Noise Attenuation Barriers

The use of barriers for noise attenuation is the least preferred option, however, the following should be considered during the design of the development where noise attenuation measures in the form of barriers, fences and vegetated buffers are required.

The design of these noise attenuation measures should not:

(a) compromise the ability to protect property from crime and vandalism; (b) obstruct or reduce passage by pedestrians to public transport nor contribute to deterioration of accessibility to public transport; (c) create sterile areas that are unusable, unsafe and negatively affect the streetscape; (d) result in continuous barrier fencing along roadways which has both visual impacts and also impacts on people and wildlife movement; (e) obstruct the overland flow of stormwater or cause increased flooding or ponding of stormwater;

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Noise attenuation measures for dwellings or building should be designed as architectural features including the stepping of buildings, angling wall alignments, and roof line variation to add interest to the form and enhance the appearance to the street frontage.

Noise attenuation measures are designed to facilitate wildlife movement while maintaining noise attenuation effectiveness by ensuring:

(a) vegetated earth mounds are considered in preference to fences or barriers; (b) suitable vegetation is provided adjacent to noise attenuation mounds, barriers and fences to facilitate wildlife movement; (c) attenuation barriers and fencing incorporate wildlife movement measures that are suitable to the species expected to use the area; (d) vegetation species selected are locally native species.


Continuous barrier fencing is avoided along trunk collector and sub-arterial roads so as to not create sterile traffic

corridors.

Views are retained where possible by using appropriate buffer distances, height, orientation and materials.

Where fencing is used it is articulated, landscaped and incorporates multiple access points for pedestrians and

cyclists. Acoustic fencing is of low maintenance design.

When using measures such as earth mounds, fences or a combination of these.

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It should be noted that a covenant may also be applied where an acoustic barrier is

required to be maintained on land to protect the amenity of the greater neighbourhood for example an acoustic fence which runs along the boundary of several individual

properties.

As stated earlier, it should be demonstrated that other attenuation measures have been considered first as alternatives to structural

barriers. For example, at the design phase of a development, consideration should be

given to the use of land between the source and receiver which can increase buffers

and assist in attenuation. Such land uses could be minor roads and/or parks.

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Methods to Minimise Impacts from Noise Emissions

(1) This is not an exclusive list but merely provides a range of examples for minimising noise emission

impacts.

(2) Siting and design - (a) Select an appropriate site for the use

considering the proximity to sensitive receiving environments and the local meteorological

conditions; (b) Design site layout to ensure building

openings, roads, parking areas and other major activities and operational areas are located away

from current or future sensitive receiving environments;

(c) Where possible use the layout of the buildings, site infrastructure and natural

topography as noise barriers; (d) Where possible confine noisy processes to

areas protected by enclosures or barriers; (e) Locate noisy processes such as loading bays and entrances/exits away from sensitive

receiving environments; (f) Locate noise sources such as air

compressors, pumps and similar in areas furthest from sensitive receiving environments, provide effective noise barriers or enclosures,

and keep doors on enclosures closed when operating.

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(3) Construction standards -

(a) Vehicle traffic areas are paved, have low gradients and are maintained

in good condition; (b) Install double-glazing to windows

and sound locks to doors facing sensitive receiving environments;

(c) Buildings housing noisy operations, activities or equipment are

constructed of suitable materials to reduce noise transmission such as ceilings and walls lined with sound

absorbing material; (d) Reduce structure-borne noise

and vibration by mounting equipment on appropriate isolation systems

designed by a specialist in this field.

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(4) Operation standards - (a) Install noise suppression devices to equipment

according to the manufacturerâ€™s specifications and ensure the efficiency of these devices is maintained;

(b) Design and maintain adequate noise buffers between noise sources and sensitive receiving

environments. In particular, install noise barriers such as screens around noisy equipment, operations and

activities; (c) Fit all diesel engines and noisy vehicles with

efficient exhaust mufflers; (d) Avoid installing machinery that may have

humming or whirring components or impulses, or annoying tonal or hammering noises. If such

machinery is installed, noise suppression devices are applied to mitigate potential nuisance;

(e) Fit effective inlet and exhaust silencers to air compressors and ensure that air pressure operated

controls and air operated valves on silos and hoppers are equipped with silencers;

(f) Where possible, substitute equipment with an equivalent quieter/lower sound power level piece of

equipment, for example, electric rather than diesel or air powered;

(g) Where possible replace alarms, horns and telephone bells with visual signs, mobile phones or

pagers; (h) Where blasting of rock or hard ground is

involved, use technologies that minimise airblast overpressure and ground vibration.

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(5) Noise management measures - (a) Ensure that openings including windows

and roller-doors facing sensitive receiving environments are kept closed and all

unnecessary openings are sealed. Install signage to alert staff and/or visitors to their

responsibilities to minimise the generation and propagation of unnecessary noise;

(b) Limit noisy routine operations to standard working hours of 7am to 6pm Monday to Friday, and 7am to 1pm Saturday. Noisy work should

not be carried out on Sundays or public holidays, except where approved as part of the

land use or another approval such as an activity under the Environmental Protection Act 1994;

(c) Conduct noisy activities at times when the likelihood for nuisance is minimised, for

example, the middle of the day; (d) Work outside of standard working hours is

limited to quiet â€œfinishing offâ€ work and �generally conducted within buildings;

(e) Limit vehicle movements, especially deliveries and truck movements, to standard

working hours;

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(5) Noise management measures - (f) Where possible, activities such as concrete pours are restricted to standard working hours. If activities are required to occur outside of these

hours, affected premises are notified of the duration and times in advance of the event;

(g) Employ regular inspection and maintenance programs to ensure noise control fittings such as

seals, doors and exhaust systems are in good working order and prompt attention is given to

loose or rattling covers, worn bearings and broken equipment;

(h) Develop and implement an Environmental Management Plan including procedures for -

(i) noise management; (ii) pollution prevention;

(iii) staff training; (iv) customer education where applicable; (v) definition of roles and responsibilities;

(vi) monitoring of performance; (vii) contingency actions.

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Fence and Planted Buffer

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Earth Mounding - Landscaped

Earth Mounding - Landscape and Barrier Fencing

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Specifications for Noise Attenuation Measures (Barriers, fences and mounds)

Type of Measure

Specifications

Earth Mounding - Landscaped

1. Area required from property boundary to pavement kerb is a minimum of 11.6 metres - buffer zone plus road reserve/ verge.

2. Mound set at 3.6 metres from back of kerb. 3. Standard street tree planting to apply in 3.6

metre zone. 4. Mound width at base equal to 8 metres. 5. Maximum mound height at apex ranges from 1

metre to 2 metres. 6. Mound batters do not exceed 1:2 (V:H) slope. 7. Earth mound is clean, compacted fill with

topsoil capping to minimum 300mm depth and minimum 100mm mulch layer over mound.

8. Mound is planted with a mixed range of local native species including large shrub/ small tree species and an under-storey of small shrub and groundcover species.

9. Mature height of - 1. large shrub/ small trees is 6 metres; 2. under-storey shrubs is 1 metre.

10.Density of planting is one plant per square metre with ratio one large shrub/ small tree to six under-storey shrubs.

11. All mounding is designed to avoid localised ponding with run-off directed towards suitable areas.

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Type of

Measure

Specifications

Earth Mounding - Landscape and Barrier Fencing

Minimum area required from property boundary to back of kerb is 7.6 metres - buffer zone and road reserve / verge. Minimum mound set at 3.6 metres from back of kerb / road edge. Standard street tree planting to apply in 3.6 metre zone. Mound width at base equal to 8 metres with 4 metres to extend within property boundary2. Mound height at apex ranges from 1 metre to 2 metres maximum. Mound batters do not exceed a 1:2 slope (V:H) slope. Earth mound is clean, compacted fill with topsoil capping to minimum 300mm depth and minimum 100mm mulch layer over mound. Mound is planted with a mixed range of local native species including large shrub/ small tree species and an under-storey of small shrub species and groundcover species. Mature height of -

large shrub/ small trees of 6 metres; under-storey shrubs of 1 metre.

Planting density is one per square metre with a ratio of one large shrub/ small tree to six under-storey shrubs. Fence is of timber materials or other approved materials with height between 1.2 metres to 2 metres. All mounding is designed to avoid localised ponding with run-off directed towards suitable areas.

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Type of Measure

Specifications

Fence and Planted Buffer

Area required from property boundary to back of kerb is a minimum 5.5 metres - buffer zone and road reserve / verge. Dedicated land for planting buffer is a minimum of 2 metres wide. Standard street tree planting to apply in 3.6 metre zone. Planted buffer is clean, cultivated top soil to minimum 300mm depth with minimum 100mm mulch layer over ground. Irrigation system satisfies the local governmentâ€™s standard specifications. Buffer is planted with a mixed range of locally native species including large shrub/ small tree species and an under-storey of small shrub and groundcover species. Mature height of -

large shrub / small trees is 4 metres; under-storey shrubs is 1 metre.

Planting density is one plant per square metre with a ratio of one large shrub / small tree to eight under-storey shrubs. Fence is of timber construction or other approved fencing products with a maximum height of 2 metres. Fence colour enhances visual amenity.

VEGETATION AND NOISE ABATEMENT

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