Arabic Fricative consonants: acousticcues of Arabic native speakers

By Maryam ALzyood

JUST University

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Abstract

The purpose of the present study is to investigate theacoustic characteristics of Arabic fricatives as well asfinding invariant cues that classify fricatives intotheir place of articulation across males and femalesspeakers. Thirteen fricatives of Modern Standard Arabic(MSA) (/f, T, D, Ð ðˤ, s, sQ, z, S, X, K, è, Q, h) wereelicited from 4 male and female adult speakers in 6 vowelcontexts (/i, i:, a, a:, u, u:/)within CVC words. Theacoustic cues investigated include the duration for eachsegment production, formant frequencies at fricativevowel transitions, amplitude measurements and spectralmeasurements in related to the spectral peak location.It was found that acoustics cues for fricatives in Arabichad patterns similar to those reported for fricatives inEnglish as well as in which the measurement of these cuesare different according to the place of articulation,voicing and vowel context among the male and femalespeakers.

Keywords: fricatives, acoustics cues, Arabic speaker.

1- Introduction

Arabic consonants have been studied by many linguistsbecause of their prominent importance in understandingArabic particularly and Arabic phonology (6) the fricativesare identified by the formation of a narrow construction maintainedsomewhere in the vocal tract, by development of turbulent airflow andby generation of a turbulence noise (1).). There are fivepositions of articulation of Arabic consonants, and ineach position there are different places for the

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articulation of these consonants (8). The five positionsof articulation are the larynx which has one place ofarticulation, the pharynx which has three places ofarticulation, the tongue which has ten places whereconsonants are articulated, the lips which has two placesfor articulation, and the nose which has one place ofarticulation (4, 5, 8, 10), these five positions for thearticulation are known as the general positions ofarticulation in Arabic.Arabic and English are relatively rich in the fricative sounds, however, Arabic has two less common fricatives, the uvular [X, ʁ] and two highly marked fricatives, the pharyngeal [ʕ, ħ] located in the posterior of the vocal tract(8). The acoustic characteristics of fricatives wereinvestigated with the aim of finding invariant cues that classify fricatives into their place of articulation. Many studies investigated the properties of the acoustic signal through which sound is transmitted from speaker tohearer and the phonological differences between male and female speakers are generally considered in terms of the static acoustic and perceptual consequences of different articulatory dimensions (5, 7, and 3). The very few studies dealing with acoustic characteristicof Arabic fricatives (3) have been predominantly concerned with a single acoustic feature and not with theway multiple cues can be integrated in order to distinguish the fricative according to the place of articulation. While some of the cues seem to be distinguished clearly in English fricatives, the same cues were used to classify Arabic fricatives (1). For example, unlike English, Arabic utilizes durational differences of both vowels and consonants for phonemic distinctions. In a study of fricatives in Cairo Arabic, Norlin(1983) found that /s, Q, z, zQ/ are characterized by a sharp peak in higher frequencies, and that the peak of /sQ, zQ/ are broader than /s, z/. The perceptual salience of F1onset was also demonstrated by Alwan(1989),who used synthetic speech to test the discrimination between voiced pharyngeal fricative /Q/ and voiced uvular fricative /X/. The author found that the higher F1onsetfor the pharyngeal was essential to make the distinction.

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As a result, the researchers, who studied the Arabicfricative consonants, provided a description of theseconsonants to show how they are articulated and produceddepending mainly on the acoustics cues for Englishfricatives to classify Arabic fricatives. In the presentstudy, the researcher attempt to examine how each of theacoustic cues found to be effective in fricativeclassification and will be served alone to distinguishthe production of fricative or will be affected by thevowel length differences in relation to the production offricatives by male and female.

2. The Arabic Fricative Consonants

The present study aims to investigate the Arabic fricative consonants. To deal with Arabic fricatives, researchers must first know how each consonant is distinguished and the characteristics of each Arabic fricative consonant; this section provides the main articulation characteristics for each sound. Voiceless Fricatives1. the Arabic / f / is a voiceless labio-dental fricativeconsonant. Example: fool (beat)2. the Arabic / θ / is a voiceless interdentally fricative consonantExample: thawam(garlic)3. the Arabic / s / is a voiceless alveolar fricative consonant Example: sarr(walk)4. the Arabic / sˤ / is a voiceless alveo - larvelarized fricative consonant. Example:saar(become) 5. The Arabic /ʃ / is a voiceless palato-alveolar fricative consonant. Example:shaal (cloth)6. The Arabic / x/ is a voiceless velarfricativeconsonant. Example: khawkh( peach)7. The Arabic / ħ/ is a voiceless pharyngeal fricative consonant. Examples: haar( hot)8. The / h / is a voiceless glottal fricative consonant .Example: haal(cardamom)

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9. The Arabic / ð/ is a voice interdental fricative consonant. Example: thawq( taste)

10 .The Arabic / ðˤ / is a voiced interdental velarized fricative consonant. Example: thaym(unjust)11. The Arabic / z / is a voiced alveolar fricative consonant. Example: zar (visited)12. the Arabic / ɣ / is a voiced velar fricative consonant. Example: ghab( absent)13. The Arabic / ʕ/ is a voiced pharyngeal fricative consonant. Example: aaj ( ivory)

Table (1) Place of articulation of Arabic fricatives

Voiced VoicelessLabio-dental fDental Ð ðˤ θAlveolar z S Post-Aleolar ʃuvular ɣ xPharyngeal ʕħGlottal h

2- Research Questions:Elicited samples taken from four subjects (2 males, 2females) were examined to answer the following specificquestions: (1) How much each of the acoustics characteristicsmentioned above, amplitude, duration, spectralmeasurements and formant frequency would serve alone andcollectively to distinguish between place of articulationof Arabic fricatives?(2) Does the acoustics cues measurement differ from maleand female? The articulation of the samples was analyzed by measuringthese cues during fricative productions in CVC words bymales and females.

3- Experiment

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The current study investigates Arabic fricatives to findthe main acoustic cues; the samples words were examinedto study fricatives in Arabic in comparison theproduction of fricatives by native speakers (male,female).

4- Participants

A group of four adult speakers (2 males, 2females) ofModern Standard Arabic (MSA), the participants are also afluent speaker of MSA; the participants are students atHashemite University. The mean age of participants is 21years, they did not have any idea about the words theywill record.

5- StimuliThe stimuli consisted of thirteen words (fool, thawp,thaym, thaweq, sayf, sayed, zain, shaal, khawkh, ghaal,harr, ayn, haal) produced in CVC syllables. where theinitial consonant is a MSA fricative /f, θ, ð, ðˤ,s, sˤ,z, ʃ, h,X, ɣ, ħ, ʕ/followed by each of the six vowels /i,i:, a, a:, u, u:/. The final segment is a consonant. Eachresulting word was repeated twice to yield a total of 104audio prompts (13 fricatives × 4 participants×2repetitions). The recorded prompts were then edited to beof equal length (18 seconds). The participants wereinstructed to repeat the word presented individually,participants read the list of words at a normal speakingrate, and were asked to repeat all of the words twice.The recording was carried out in the language laboratoryat English department of the Hashemite University byusing the ICM program. Each word lasted for two to threeseconds on the screen and then the following word wasrecorded .there were repeated word in case a participantdid not produce the word correctly or mispronounce it andfinally the recordings were analyzed by using PRAATsoftware.

6- Measurements

The following measurements were taken for each fricativesound. All measurements described using audio file

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analyzed by the PRAAT program. The resulting sound fileswere then transferred into PRAAT for segmentation andfurther analysis for each fricative segment; four pointswere taken into consideration: duration, spectralmeasurements, amplitude and the second, third and fourformant frequencies. Fricative duration was measured in related to thebeginning of frication, the offset of fricative/beginningof the vowel and the end of the vowel in seconds (Ms.),the three basic formant frequencies were expressed inHertz (Hz) and finally the amplitude in (Db). So wedetermine the mean average for each word, the ratio ofthe males articulation to the females articulation wascomputed for each word to compare the variation inspeaker and speaking rate.

7- Results

By basing the analysis on percent of duration,frequencies and intensity of the frication production, itwill be possible to confirm whether the difference in theproduction of males and females results have asignificant relation in producing the Arabic fricativewith regards to acoustics cues for each word.

7.1 DurationIt’s risky to assign a particular duration to fricativesnoise segment, because the duration is influenced bynumerous contextual factors (11). As shown in chart 1,the duration of noise segment varies with place ofarticulation, voicing sound and vowel context, so therewas no significant interaction between fricativesdurations and speaker (male and female). As shownpharyngeal- dental /ðˤ/ and glottal fricative /h/ had theshortest duration with a mean of .20 ms and .13ms. Thisaveraged across voicing and vowel context followed thesegment, as compared to alveolar and post alveolar; bothhave the longest duration with a mean of.50ms. but wehave different distinction between voiced and voiceless,the voiced alveolar /z/ with mean 55 ms has longerduration than voiceless alveolar/s/ with mean 50ms,nosignificant differences were found among voiceless

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labiodentals, voiced dental fricatives(.39ms) or betweenpost alveolar and uvular fricatives( 50 ms) and theirplain counterparts between alveolar (.55ms) and glottal(.13ms).finally, the sum of duration for men was 8.88msto female was in contrast 9.04ms both male and femalemake similar distinctions in durations among fricativesin CVC syllables and the one observed with absolutefriction noise duration, considering the differences ofplace of articulation, voicing and vowel context.

0

0.1

0.2

0.3

0.4

0.5

0.6

Voice Column1

Chart1.Mean duration of frication noise as a function of place of articulation and voicing vowel context are presented in CVC syllable.

7.2 Formant frequency The means and standard deviations for formant frequenciesare shown in Table 2.The effect of vowel length on F2frequency was significant relation with /i-i:/contrast /a-a:, u-u:/F2 frequencies. For both voicedand voiceless fricatives dental and voiceless uvular hada significant lowest frequency because the followedvowels was (u:), in contrast to the alveolar which hadthe highest frequency because followed with vowels (i:),additionally, no significant differences was obtainedbetween uvular and alveolar. There was also a main effectof Vowel context; As expected, F2 (measured at the onset

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of high front vowels /i,i:/ with mean frequency of 2240and 2411 Hz were significantly higher than all othervowels Also, the F2 frequencies of back vowels (/u, u:/.In addition, alveolar fricatives (/T - s/) have a highestF2 about (2279, 2244Hz for men, 2324, 2411 Hz for women)additionally, no significant difference was obtainedbetween uvular and pharyngeal (/X - è/), the F2frequencies of both dental and labio-dental werestatistically similar (means are reported in Table 2). Sothe effect of vowel length on F2 frequency was notsignificant except for the /i -i:/ contrast, for whichlong vowels introduced higherF2 frequencies.

Moreover, women have a higher frequency in differentrange of F2, F3, F4 frequencies, this difference relateprimarily to the length of the vocal folds(6).There aresignificant differences between fricative voiceless andvoiced; in all averages voiced sounds have a higherfrequency than voiceless for both men and women as shownin the table 2. As a result of F4 pharyngeal and glottal had asignificantly lowest F4 and the higher frequency withpharyngeal dental for women and alveolar for men, ingeneral the alveolar sound[s] had a higher frequencyfollowed with (i:).

Place of articulation

F2/Male F3/Male F4/Male F2/Female F3/Female F4/Female

Labio dental

voiceless 1457 3175 4199 1608 3195 4180

Dental voice 1403 3329 4182 2093 2983 4606voiceless 1679 3382 4352 1755 3013 4112

Alveolar voice 2279 3381 4466 2324 2998 4532voiceless 2244 3551 4683 2411 3145 4333

Post-Aleolar 1971 3602 4437 2214 3345 4226uvular voice 2022 3501 4441 2307 3116 4521

voiceless 1382 3502 4250 1794 3312 4332

Pharyngeal

voice1991 2892 3842 1987 2770 3913

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voiceless 1579 3073 3952 1898 2787 3897

Pharyngeal-alvelor

voiceless

1971 3602 4437 2214 3345 4226Pharyngeal-dental

voice

1688 2952 4028 1664 3611 5997

Glottalvoiceless 1913 3563 3563 1886 2854 3964

Table 2 the mean of the formant frequencies for both male and female

7.3 Spectral peak location Specifically, three main acoustic features have beenexamined in research aimed to distinguish Arabicfricatives: the spectral properties of the fricationnoise, the relation between the frequency characteristicsof frication noise versus the vowel, and duration offrication noise.spectral peak location information is very important forspeech recognition system, particularly, the fricativesound, it’s very clear from comparing the spectrograms infigures 1 and figure 2 that the spectra for alveolarfricatives contain relatively higher frequency energythan the spectra for palatal. As a rule of thumb foradult male talkers(7), the major region noise energy forthe alveolar fricatives lies above 4 kHz. In contrast,the palatal fricatives have significant noise energyextending down to about 3 kHz..

Time (s)0.775 2.5450

5000

Freq

uenc

y (Hz

)

Time (s)0.775 2.5450

5000

Freq

uenc

y (Hz

)

Time (s)0.775 2.5450

5000

Freq

uenc

y (Hz

)

Figure 1 waveforms and spectrogram for isolated production of fricatives /s/ and/ ʃ/

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Figure 1 waveforms and spectrogram for isolated production of fricatives /s/ and/ ʃ/

/s / /ʃ/Figure 2 waveforms and spectrogram for isolated production of fricatives in CVC /s/ and/ Figure ʃ/

As we notes Figure 2from spectra the alveolar fricatives has more energy at higher frequency compared to palatal.

Figure 3 FFT and LPC spectra for fricatives / ʃ /, /S/

Figure 4 Wave form and spectrogram for isolated production of the fricatives /v/ and / θ/

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Finally the spectrum is primary because the noise energy for strident is intense and phonologically distinctive. However it also the transition interval could aid the identification of fricatives and the relative values of the noise or transition interval varied with vowel context. For example the noise segment [s] was not effected a cue in the [i] context as it was [a] or [u] .it may conclude that Arabic fricatives like English fricatives identified by noise segment as in strident as well as formant transition as in nonstrident(3, 12). As well there is a significant difference between male and female in the mean of F4 frequency (12).

7.4 Intensity The amplitudes of formants have significant relation interaction between male and female. However, it is knownthat formant amplitudes are affected by the intensity of the source and formant frequencies, when formant frequencies are close together, they boost each other, resulting in higher formant amplitudes (3, 12), If the second formant amplitude is high, then the other formant amplitudes will be higher.

Figure 5 frication noise normalized RMS amplitude

(dB)for /s /Table 3 contains the average of amplitude for both males and females, we found the alveolar and pharyngeal dental have a highest amplitude (77Db) also there is no

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differences within dental and uvular, but glottal has the

lowest amplitude.Table 3 The mean of the amplitude for Arabic

Place of articulation

MaleFemale

Labio dentalvoiceless7673Dental voice7974

voiceless7774Alveolarvoice7777

voiceless7476Post-Aleolar8378uvularvoice6161

voiceless7673Pharyngealvoice6077

voiceless5876Pharyngeal-alvelor

voiceless7776

Pharyngeal-dental

voice8477

Glottalvoiceless5954

In chart 2(show the average of amplitude for both malesand females ). In general men have a higher intensitythan women because the differences in size and shape ofthe vocal tract, also the voiced fricatives have a higheramplitude that voiceless need more muscular effort thanthe voiced fricative ones and a powerful exhalation thanthat in the articulation of the Arabic voicedconsonants(6)

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0102030405060708090

MaleFemale

8 Conclusion The main purpose of the present study is to investigatethe acoustic characteristics of Arabic fricativesproduced by Arabic speakers (males, and females). Theresults obtained from the cues investigated in the samplewords were: amplitude measurements (normalized andrelative frication noise amplitude), spectralmeasurements (spectral peak location and spectralmoments), formant frequency for fricatives (F2, F3, F4information at CVC) and duration for fricative noisesegment. Depending on the results obtained in perviousresearch for fricatives in English, spectral measureswere the most efficient in distinguishing among thedifferent places of fricative articulation. In regardswith gender effects the perceptually of Arabic fricative,the result consistently showed that females would havehigher formant frequencies than same aged males, and thatfemales would have reduced formant amplitudes as comparedto males.

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9 References

1- Aid, Mushira,(1990)Perspectives on Arabic linguistics, John Benjamins Publishing

2- Al-Ani, S. H. (1970). Arabic Phonology. Paris: Mouton, The Hague.

3- Al-Khairy, Mohamed. Ali. (2005). Acoustics characteristics of Arabic fricatives. A dissertationpresented to the graduate school of the University of Florida in partial fulfillment of the requirements for the degree of doctor of philosophy .University of Florida.

4- Al-Nahda Al9arabiyya. Beirut. Lebanon.5- Al-Qudah , Muhammad and et al . 1998. Al-Wadeh Fi

Ahkam Al- Tajweed. (Third Edition). Dar Al- Nafai's ,Amman . Jordan

6- Al-S9raan, Mahmood .(no date ) . 9lm Al-Lugh :MuqaddemaLilqare' Al9rabi. Dar

7- Alwan, A. (1989). Perceptual cues for place of articulation for the voiced pharyngeal and uvular consonants. J Acoust Soc Am 86

8- Bawazeer, Ameen . 1988. Al-Mukhtar Al-Mufeed Fi AhkamAl-Tajweed. Dar Al9alyan lilnashrwa Altawzee9.Jedda, Saudi

9- Fant, G. ~1973!. ‘‘Acoustic description and classification of phonetic units,’’in Speech Sounds and Features ~MIT, Cambridge! ~reprinted from Ericsson Technics

10-Jarrah, Mufleh,(2013), Arabic Fricative Consonants, International Journal of Humanities and Social Science Vol. 3 No. 21 [Special Issue – December 2013]

11-Katz F William and Bharadwajcsneha,(2001) Coarticulation in fricative-vowel syllables produced by children and adults: preliminary report. Clinical Linguistics &Phonetics, ISSN 0269-9206 print/ISSN 1464-5076 online Ñ 2001 Taylor & Francis Ltdhttp://www.tandf.co.uk/journals

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12-Kent, R. D., and Read, C. ~1992!. The Acoustic Analysis of Speech ~Singular, San Diego, CA

.13-Norlin, K. (1983). Acoustic analysis of fricatives

in cairo Arabic. Working Papers, Phonetics Laboratory, Lund University 25, 113–137.

14-Odisho, Edward Y. Gorgias Press LLC, 2005

15-Verónica Rivas, María, August 2006, Does the perception of fricatives correspond to their production? The case of Italian vs. Dutch, General Linguistics Faculty of Humanities, University of Amsterdam August 2006

10 Appendix

AALIADF0F2F3F4intisi

ty

fool0.30215320803256442380Thawem0.22715718853176422083thaym0.15415813773118389282

thaweq0.30315320873168419184sayf0.52118723583521436081

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sayed0.44118518872431343182zain0.55417222703423418579

shaal0.50716322153205401383khawak

h0.43217416963363416483ghaal0.50915517313102378480haar0.21916415672865371683haal0.11616220593019389377ayn0.25216416702911376680

RANADF0F2F3F4intisi

tyfool0.23414573175419980

Thawem0.31215716793382435277thaym0.41215816882952402865thaweq0.31315314033329418278sayf0.53118722443551468376

sayed0.44118519713602443777zain0.58417222793381446677

shaal0.53716322933612444683khawak

h0.47217413823502425076ghaal0.50715520223501444173haar0.24916415793073395278haal0.12216219133563356377ayn0.27216419912892384274

HANIDF0F2F3F4intisity

fool0.38814522513397425076Thawem0.25516320983347440277thaym0.26316014123002398684

thaweq0.51215621513120436979sayf0.45316922423314437884

sayed0.30917320132433335677zain0.55517022123365438770

shaal0.51521623143126395483khawak0.30515721673200453961

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hghaal0.48715019562923397876haar0.30116420763347444858haal0.43216017382397379159ayn0.32215719052933436060

OMARDF0F2F3F4intisity

fool0.21914516083195418079Thawem0.35516317553013411274thaym0.36316016643611599777

thaweq0.56215620932983460674sayf0.48316922193145433376

sayed0.31617322143345422676zain0.57517021642998453277

shaal0.54521623073116344478khawak

h0.38515717943312433261ghaal0.48915017673303387673haar0.36116418982787389777haal0.43616018862854396472ayn0.35215719872770391377

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