Does the speech of Turkish-speaking phonologicallydisordered children differ from that of children speaking

other languages?

SEYHUN TOPBAS

Anadolu University, Turkey

(Received 10 July 2004; accepted 10 November 2004)

AbstractHow phonological disorders should be categorized in Turkish children remained vague for a longperiod of time due to a lack of normative studies. This paper reports the phonological systems of 70phonologically disordered children, aged 4;0–8;0, in comparison with the results of a normative studyof 665 Turkish-speaking children, aged 1;3–8;0. The current focus is on two aspects of development,mainly the differences between disordered and normal consonant acquisition and phonological errorpatterns from both longitudinal and cross-sectional data. The second concern of the paper is to sub-classify phonological disorders as proposed in the existing literature by examining the applicability ofthese proposals to Turkish, a typologically different language. It has been indicated that similardevelopmental trends occur across languages but consonant acquisition is more rapid anddevelopmental errors are more predictable in Turkish. There is evidence for ambient languageinfluence. Mostly, the sub-classifications of phonological disorders are valid for Turkish-speakingchildren with apparent saliency to language.

Keywords: Phonological disorders, phonological acquisition, classification, cross-linguistic, Turkish

Introduction

Phonological development and disorders is still an intriguing area for cross-linguistic

comparisons. Cross-phonologic studies on language acquisition suggest that there are only

broad developmental patterns that can be described as universal. So the idea that children

are sensitive to the ambient language is not new. Children’s phonological inventories are

not similar within and across languages, rather the similarity is observed on core features

(Ingram, 2004). These findings are important for less researched languages as in the case of

Turkish, in which assessments for impaired language are compared according to children

acquiring other languages.

Some cross-phonologic studies of English, German, Potunghua, and Cantonese implied

that children learning languages other than English may well use similar strategies of

structural and systemic simplifications, but the way in which those strategies were

Correspondence: Seyhun Topbas, Anadolu University, Centre for Speech and Language Disorders, Yunusemre Campus, 26470

Eskisehir, Turkey. Tel/Fax: +90 222 335 2337. E-mail: stopbas@anadolu.edu.tr

Clinical Linguistics & Phonetics, Sept–Oct 2006; 20(7–8): 509–522

ISSN 0269-9206 print/ISSN 1464-5076 online # 2006 Informa UK Ltd.

DOI: 10.1080/02699200500266331

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

implemented in terms of realization rules might vary according to the phonetic and

phonological structure of the language being learned (Dodd, 1995; Fox and Dodd, 2001;

So and Dodd, 1995; Hua and Dodd; 2000). However, such studies are few and there is a

need for descriptions in other languages. This will eventually allow the evaluation of

universal classification systems of phonological disorders, and which measures should be

taken into account as the effect of the ambient phonology on disorders.

Classifying sub-groups of children, although widely recognized (Shriberg &

Kwiatkowski, 1982), is controversial. In reviewing the literature Fox and Dodd (2001)

discussed the issue of classifying speech disorders. They summarized that basically medical-

etiological, clinical-inferential/linguistic perspective and psycholinguistic approaches are

widely used in evaluations. Taking into account the advantages and disadvantages of such

approaches, Bradford and Dodd (1996) combined clinical-inferential/linguistic perspective

and psycholinguistic approaches and proposed a four-way classification system based on

the surface error patterns: articulation disorder, delayed phonological development,

deviant-consistent phonological disorder, and deviant-inconsistent phonological disorder.

Using this sub-classification, Goldstein (1996) analysed 20 phonologically disordered

Spanish-speaking Puerto-Rican children; So and Dodd (1995) analysed 17 phonologically

disordered Cantonese-speaking children; Topbas and Konrot (1998) analysed ten

phonologically disordered Turkish-speaking children, Hua and Dodd (2000) analysed 33

phonologically disordered Potunghua-speaking children; and Fox and Dodd (2001)

analysed 110 phonologically disordered German-speaking children, and they all found

support for the proposed sub-classification, although there were minor differences. All

these studies have concluded that although the sub-classification may fit different

languages, which error patterns should be considered unusual or inconsistent and used

as criteria for assessment varies from one language to another.

Bearing in the mind that whether a child should be considered disordered or non-

disordered should be assessed in relation to the normal patterns of the ambient language,

there was a need for normative studies in Turkish. Turkish is one of those languages in

which some aspects of universal and language specific variability have been demonstrated

by applying either a process based (Topbas, 1997; Topbas & Konrot, 1998) or relational

based approach (Topbas & Dincer, 2002). However, only a small number of subjects have

been presented. So, due to lack of normative studies, it remained vague for a long period of

time which error patterns should be considered unusual (and used as criteria for

assessment), and how phonological disorders should be categorized in Turkish children.

It is basically this question that the author would like to answer with data from a large

scale normative study in comparison with phonologically disordered children. Special

emphasis will be given to sub-classifying the disorders as a preliminary analysis to aid

further studies in Turkish. By doing so, evidence will be presented about specific and

universal aspects of variability, and concerning the validity of classification systems for

speech disorders, thereby enabling the results to be compared with existing literature in

other languages.

Brief review of Turkish phonology

Turkish belongs to the Altaic group of language families, and the basic word order is

subject-object-verb (SOV). Its agglutinating nature allows both derivational and inflec-

tional suffixes added to roots leading to long strings of words. The orthography assigns

letters to 21 consonants /p, b, m, n, t, d, ts, dz, k, g, X, f, v, h, s, z, s, z, l, , j/ and eight

510 S. Topbas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

vowels /i, Y, y, (O), 2 (a), E, %, 3/ and word-final clusters are restricted to sonorant/

fricative+non-continuant (stop, affricate) i.e., /rk, rt, rp, nk, nt, nc, sk, st, lk, lp/. Word-

initial liquids are borrowings. The allophonic variations of /k, g/ are ruled phonologically

where before back vowels [k, g] occur and before front vowels [c, ]. The controversial ‘‘g’’

or ‘‘soft-g’’, the voiced velar fricative, [X], gave way to lengthening of the previous vowel in

syllable-final position and post-vocalically; in syllable-initial position it does not occur. /v/

has an allophone in intervocalic and final positions: a frictionless continuant [u]. /l/ is

velarized [ ], when it occurs with a tautosyllabic back vowel and palatalized [l] when it

occurs with a tautosyllabic front vowel. The alveolar flap / / is treated as a liquid in general

as its allophonic variations are not context dependent in Turkish: [ , , ]. One main

phonological constraint is the word-final devoicing of voiced non-continuants /b, d, g, dz/where they alternate to /p, t, k, ts/. Other allophonic variations are vowel and consonant

harmony. It is a syllable-timed language, having almost equal duration on syllables. Stress

appears to be on the final syllable although there are exceptions.

Phonological acquisition in Turkish

Although there have not been many studies, different aspects of acquisition have been

studied in normal and disordered Turkish children recently by Topbas, 1988, 1994, 1996,

1997, 2004a; Acarlar & Ege, 1996; Ketrez, 1997; Topbas & Konrot, 1998; Topbas &

Kopkallı-Yavuz, 1998; Kopkallı-Yavuz & Topbas, 2000; Topbas & Dincer, 2002; Yavas &

Topbas, 2004. (For detailed information reader can refer to Topbas and Yavas, 2006.)

According to this research, Turkish children tend to acquire the phonology of their

language very rapidly, with the exception of / / and clusters, following similar paths

observed in other languages (Ingram, 2004). Evidence for language specific aspects has also

been derived from error patterns and from the early suppression of unique phonological

rules of Turkish. Table I and Table II present summaries of acquisition of Turkish

phonology from the normative sample (Topbas & Yavas, 2006).

As can be seen from Table I, by age 3;6 all the sounds seemed to be established at syllable

initial and syllable final positions. Among the very early sounds established by 90% of

children between the ages 13–15 months were labial plosives, alveolar plosives, velar

plosive, nasals and the glide /j/. The order of acquisition can be summarized as

stops.nasals.affricates.glides/liquids.fricatives.flap. The voiced fricative /z/, the glottal

fricative /h/ and the flap / / and its allophonic variations emerged at around 2;6 but only

stabilized at around 4;0 years of age. Among the clusters nasal+stops /nk/ appeared earlier

than flap+stops / t, k/ and liquid+stops /lp/. Although the liquids seemed to occur in

children’s speech much earlier they were subject to deletion when they occurred in clusters.

Table II shows the percentage of children in each age group who used these processes in

at least four words. The most frequently observed processes are summarized in the table.

Most of the processes were suppressed between the ages of 3;6, and 4;0 at the latest. If 10%

of the children used the same error pattern, it was considered as a process. The error

patterns were high around two years of age, which might be due to the increased vocabulary

use at this age. Reduplication, SI voicing, and fronting are among the earliest to be

suppressed. Word final devoicing was observed for /z/ only. Assimilatory substitutions,

although observed with high frequency, both progressively and regressively, disappear

early. The few error patterns observed after age four were liquid deviation and cluster

reduction.

Phonological disorder in Turkish speakers 511

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

Table I. Age of stabilization of phonemes at four word positions (n5665).

Age group

by 75% of children by 90% of children

SIW I SIWW SFWW SFWF SIWI SIWW SFWW SFWF

1;6–1;11 b, d, k, t, m,

n, p, j,

b, d, t, m,

p, k, g, n

m, n, ,

p, k, l,

p, k, c, t,

m, n, j

b, d, k, t, m, b, d, t, m, m, n, , p, k, t,

m, n, j

2;0–2;5 g, , ts, dz,

l, s, s,

ts, dz, j, l, ł,

s, s,

u, ts, s, ts, u, s, s, l, p, g, t, n, ,

ts, dz, j, l,

p, k, g, n,

ts, dz, j,

p, k, l, u c, ts, u,

2;6–2;11 f, v, z, z, h, u, s, ł, f, z, s, s, s, s, l, ł, s, s, ts, ł s, s, l,

3;0–3;5 f, z, h z, f, h z, h, f, v, z, z, h f, z, z, v z, f f, z, z, h

3;6–3;11 All clusters h h,

4;0–4;5 All X All X All r, X r X, clusters

4;6–4;11 All All All All All All All clusters

Table II. Summary of percentage of phonological processes by age by 90% of children (n5665).

Structural simplifications 1;6 2;0 2;6 3;0 3;6 4;0 4;6 5;0 6;0.

Reduplication 41 9 1 – – – – – –

Syllable deletion (stressed/non-stressed) 37 30 22 13 2 – – – –

Consonant deletion (SI, SF) 19 21 11 6 2 – – – –

WF Cluster reduction 56 98 71 48 30 4 3 1

Assimilation /consonant harmony 15 22 17 3 1

Systemic simplifications

Liquid deviation 76 90 55 42 24 8 3 1

Fronting of velars 28 46 10 2

Stopping of fricatives/affricates 44 58 36 16 5 1

Deaffrication 7 13 5 0.5

Affrication 8 19 6 1

Voicing (SIWI and SIWW) 38 11 3

WF Devoicing /z/ 21 45 17 1

Metathesis 9 11 2

Backing to palatals and velars 3 6 2

512

S.

Top

bas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

Method

Participants

Seventy monolingual Turkish-speaking children, aged 4;0–8;0 years, participated. They

were diagnosed either at faculty hospitals or other clinics as speech disordered and referred

to Anadolu University, DILKOM (Education, Research and Training Centre for Speech

and Language Disorders) for detailed assessment and therapy. The author, who is a

speech-language pathologist, had assessed them as phonologically and/or articulation

disordered. A laryngologist and a paediatric neurologist also examined the children. No

definable audiological or specific cognitive problems were found. Children with articulation

disorders due to organic etiologies such as cleft palate were not included in the study. The

receptive and expressive language of the children was tested as age appropriate on the

Peabody Picture Vocabulary test (Turkish version). Children with mild expressive delay

were also included since phonological disorders often co-exist with developmental language

delay. None of the children had had any phonological intervention at the time of the

assessment.

The normative (ND) data comes from 665 children aged 1;3–8;0 years, which were

collected both longitudinally and cross-sectionally, for the standardization of an

articulation and phonology test. For comparison with the phonologically disordered

(PD) children in the present study, the children were combined into yearly age bands. The

characteristics of the participants and age groupings were given in Table III.

Data collection procedure and materials

The data used in this study were obtained during the assessment phase. Thus, data

collection was based only on elicited speech samples using the Turkish Articulation and

Phonology Test–SST (Topbas, 2004b). SST is the first detailed standardized phonology

test for Turkish children including the following two subtests:

Assessment of Articulation (SET). This sub-test contains 93 pictures based on a picture-

naming task to examine the child’s articulatory competence with speech sounds. Pictures

Table III. Subject information and means and standard deviations by age on PCC and PCE.

Group Age N Girls Boys

Mean age.

year

(month) SD

PCC PCE

X SD X SD

1 1;3–2;0 41 19 22 1;5 (17) 0.27 42.80 12.42 52.82 11.20

2 2;1–3;0 47 22 25 2;5 (29) 0.19 71.42 11.05 26.80 10.51

3 3;1–4;0 41 27 14 3;4 (38) 0.38 94.85 4.44 7.12 5.84

4 4;1–5;0 57 25 32 4;4 (52) 0.27 98.19 2.44 2.85 3.48

5 5;1–6;0 63 33 30 5;3 (66) 0.26 97.92 2.85 3.28 3.66

6 6;1–7;0 159 78 81 6;3 (78) 0.41 98.66 2.35 2.19 3.28

7 7;1–8;0 128 75 53 7;0 (88) 0.44 99.42 1.51 0.97 2.28

8 8;0. 129 66 63 8;1 (92) 0.38 99.47 1.25 1.00 2.31

Total ND 665 345 320 5;4 2.15 93.25 15.47 7.05 14.27

9 Phonologically

Disordered (PD)

70 38 32 6;4 1.76 62.74 18.43 34.95 16.91

Grand Total 735 383 352 6;2 3.12 87.90 22.78 12.35 21.99

Phonological disorder in Turkish speakers 513

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

were mostly nouns, and basic colour terms known by young children. The children were

asked to say the target word pictured. If the child failed to produce the item, an imitated

response was expected.

Phonological Analysis Sub-test (SAT). This test is based on phonological process analysis. It

contains 13 pictures of thematic compositions to elicit expressive language sample in

continuous speech. The pictures were appropriate culturally for spontaneous data

collection based on narration, dialogues and conversation. The children were asked to

describe the picture. They were prompted as ‘‘Can you describe what is happening here?

What happened? What do you see in this picture?’’ A conversation was maintained by

questions in relation to the pictures such as ‘‘When is your birthday? Do you also give

parties? Who/what is this? Where does the ambulance go? Did you see an accident?’’ The

words in the test were chosen to provide a representative sample of Turkish phonology.

In SST each phoneme occurred in the following positions:

Syllable-initial word-initial (SIWI) pil (battery)

Syllable-initial within-word (SIWW) intervocalic ka-pı (door)

-C, C- post-consonantal kar-puz (watermelon)

Syllable-final within-word (SFWW)

-C, C- pre-consonantal sap-ka (hat)

Syllable-final word-final (SFWF) top (ball)

Word-final Clusters Turk (Turkish)

The assessments lasted about 1 hour. The recordings were done by speech-language

pathology trainees in a specially designed phoniatrics speech laboratory and recorded on

Sony MZ-R70 Mini-disc digital recorders with a Shure SM48 microphone.

Data analysis procedure

Transcription reliability. The transcriptions of the data were first transcribed by consensus

using IPA and PRDS symbols by MSc students in speech pathology and then by four

speech pathology graduate research assistants who were well trained in phonetic and

phonological analysis. Lastly the reliability analysis was computed by inter-rater reliability

analysis of the first author with the four assistants (91%). This was done on random

sampling of 10 mini-discs. In each disc there were four children’s data. So a total of 40

children’s speech was used for transcription reliability. Then inter-transcribers reliability

correlation coefficient measure was computed among all by Cronbach Alpha as

alpha5.8293 (Hotelling’s T-squared5252.21, F5124.27, sig .000).

Analysis measures. Overall data analysis was done through the forms that were developed

for the SST test. For the present research the transcription of each child’s data were

scanned for the following measures:

Percentage of consonants correct (PCC). In the articulation sub test of the SST test each

phoneme occurred at least four times (except /b, d, g, dz/ since they do not occur word

finally) and in the phonological analysis subtest several times. A phoneme was accepted as

stable if it occurred correctly in at least two different syllable positions of three different

words of the four opportunities. Imitated responses were not analysed. The formula

514 S. Topbas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

proposed by Shriberg and Kwiatkowski (1982) was used to compute the production

percentages: correct production of consonants divided by target attempts X 100.

Percentage of consonants in error (PCE). PCE was calculated from the phonology subtest

based on spontaneous speech in order to show the variability found in continuous speech. It

is the number of times consonants (deletions and substitutions) were produced in error

divided by the total number of consonants X 100.

Error patterns as percentage of phonological processes (PPP). A detailed analysis was done

through the assessment forms of the phonology sub-test in spontaneous language sampling.

For each child, a process had to be used in at least three different words and used by at least

10% of the children. The percentage of occurrence of processes was computed by the

adapting the formula above. Then, the data were classified according to normative data as

persisting, unusual and variable/inconsistent patterns. For the disordered data a sub-

classification of errors due to severity levels was added to the analysis. Besides descriptive

statistics, a MANOVA, multiple regression and discriminant analysis were used to verify

the age, and gender effects in comparison with disordered development as well as sub-

classifying the error patterns.

Results

Quantitative analysis of performance in phonemic accuracy by age and gender

The means and standard deviations of phonologically disordered children (PD) compared

to normally developing children (ND) according to age, gender and on two measures, per

cent consonants correct (PCC) and consonants in error (PCE) scores can be seen in

Table III. As can be noted, the performance of the PD group was considerably lower on

PCC measures compared to the ND children at all ages and was high in PCE as expected.

Comparison of age and gender effect by MANOVA showed significant age effect in two

measures (PCC F8, 7265827.083, p,.000, R25.994; PCE F8, 7265738.697, p,.000,

R25.918), and post-hoc Tukey HSD analysis showed differences between Group 1, 2 and

all the other groups but no significant differences were found between Group 3 and 4, 5, 6,

7, 8 and 9. This might mean that consonants are produced correctly at around 3;0 years of

age, and that there is not much change after that. No significant difference was found

between the first and second ND group and PD group, which might be interpreted that PD

children’s performance is similar to that of 2;0–3;0 year olds.

As for gender, there seemed no differences between the two gender groups of PD and

ND children at all age groups, on PCC and PCE measures as shown by MANOVA results

(gender: boys vs. girls X conditions: nine groups: PCC F7, 7175.224 p..636; PCE F7,

7175.423 p..516). The gender effect for phonologically disordered children was further

analysed separately by independent samples t-test for PCC and PCE measures but no

significant gender difference was found (PCC t51.345 p..183 and PCE521.355

p..181). A summary of regression analysis by age groups of ND and PD children

suggested that the PCC scores of the PD children were significantly lower than the ND

children (r25.922 F56608.46 p,.000). Figure 1 gives a summary of the PCC of ND and

PD children on each phoneme by age. The most difficult and missing sounds for PD

children were fricatives and liquids, and flap / / which are the latest sounds acquired by the

ND children. Moreover, although the velars were acquired early in ND children they were

subject to error in PD children.

Phonological disorder in Turkish speakers 515

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

Phonological production accuracy

Phonological error patterns. The normative data showed that although almost all the

phonemes were acquired earlier and articulated correctly in the picture-naming task, error

patterns were observed in the spontaneous speech of the ND children. In the normative

study, these error patterns were defined as structural and systemic phonological processes

by descriptive statistics. These error patterns were obvious in the PD children’s speech as

well. General overview of the results suggests that most of the PD children behave as

younger ND children.

Sub-classification of phonological disorders. The error patterns of PD children were very

variable compared to ND children, some of which were identified as delayed error patterns

typical of ND but were used with high frequency and were not suppressed at the expected

age. The error patterns used by PD children are subdivided into the following categories as

illustrated in Figure 2.

1. The processes that are commonly used among ND children, but which were not

suppressed at around the expected age and which were still used after the age of 5;0,

were grouped under persisting normal processes as described by Grunwell (1985)

and Dodd (1993).

2. The processes that are rarely used or not used among ND children and that were

somehow consistent were grouped as unusual processes. This group showed a

disordered development (Leonard, 1985; Dodd, 1993). Consistency in this study

means that the error patterns can be explained or interpreted systematically by rules.

3. The processes that were not used among ND children, or that were found to be very

idiosyncratic and variable were grouped as inconsistent/variable processes. This

group showed a disordered development as well and the error patterns were very

inconsistent. Inconsistency in this study means that the error patterns cannot be

explained or interpreted systematically by rules but defined in someway and which

cause high unintelligibility. For example, a phoneme can be substituted for different

targets elsewhere.

The delayed error patterns were the ones used by 90% of ND children. They were much

more predictable when compared with children’s error patterns that use unusual and

idiosyncratic patterns. When compared with the normative data, liquid deviation is high in

both ND and PD groups. Consonant deletion was high with respect to SI and SF within

Figure 1. PCC for each consonant by the normative and phonologically disordered group (n5735).

516 S. Topbas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

word positions in both groups. Specifically, in WW positions since the liquids were

acquired late, they were subject to deletion. However, in SFWW positions a vowel

lengthening process was observed which might imply that the children are somehow aware

of the position of the liquid/flap but cannot produce it. Other than liquids/flap, SI and SF

consonant deletion occurred for /h/, most frequently at WI and WF positions. /n/ was

subject to deletion as well at WF positions. Backing to velars was observed in both groups

of children, not frequently though in ND and suppressed at early ages; however palatalising

to [s] was more frequent.

Severity measures

In order to find out any relation between severity levels on PCC scores and sub-groups of

processes used, the scores were grouped into four levels as proposed by Shriberg and

Kwiatkowski (1982). The PCC scores were then compared by discriminant analysis

according to severity levels on PCC (Table IV) and post-hoc analysis showed significant

differences between the severity levels (F3, 665120.502, p,.000). Two of the nine children

who had scored 85%.correct, were defined at the mild-level 1, who presented errors in

Figure 2. Percentage of persisting, unusual and inconsistent phonological error patterns used by phonologically

disordered children.

Table IV. Discriminant analysis for severity levels on PCC.

Severity

level PCC N Mean SD Function Eigenvalue

Wilks’

Lambda Sig. p

Canonical

correlation

1.00 85.mild 9 88.77 2.04 4.035

2.00 71–84 moderate 17 76.58 4.01 2.30

3.00 51–70 severe 19 59.84 4.46 26.076 6.951 .126 ,.000 .935

4.00 50, very severe 25 39.24 10.49 22.977

Total 70 60.2714 19.48

Phonological disorder in Turkish speakers 517

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

fronting palato-alveolars /s/ and /ts/ to [s] and the liquid deviation of / / only. The 17 (24%)

children who scored 71% to 84% correct were defined as moderately impaired at level 2,

and showed error patterns in liquid deviation, assimilation, cluster reduction, stopping of

fricatives and affricates, fronting of velars and palato-alveolars, SI and SF consonant

deletion, metathesis, SI voicing (prevocalic), WF devoicing, and deaffrication. Five of these

PD children used backing as well. However, only three children within this group had used

gliding of fricatives, which is a non-developmental pattern with low frequency as well as

persisting ones. 19 children who scored 51% to 70% correct were defined as severely

disordered at level 3, and they used unusual processes as well as delayed processes with a

high frequency. Thus, 27% of these children used stopping of liquids, stopping of nasals,

gliding of fricatives and nasalization of fricatives. Twenty-five children (37%) who scored

below 50%,correct were defined as very severely disordered at level 4, and they showed

error patterns which were unusual and inconsistent/variable as well as delayed processes. In

this group only three children used idiosyncratic velarization (/k/-ization), one child used

/h/-ization, but with high frequency. These children used /k/ and /h/ elsewhere in their

speech. Systematic sound preference was used by three children, who used /t, d/ for a lot of

target phonemes.

Discussion

This study reported comparative data from normally developing and phonologically

disordered Turkish children. The results indicated that developmentally consonant

acquisition seems more rapid and error patterns are more predictable. However, no

gender difference was found in both the ND and PD data. The disordered data showed

significant deviation from the ND data. The phonetic inventories of children were very

restricted. The per cent correct consonants and the error patterns used differed

considerably from those of the ND children. The more the severe the children’s PCC

scores the more unintelligible they were. The error patterns of the PD children could

further be analysed in three sub-groups. These are delayed developmental errors, unusual-

consistent patterns and inconsistent-variable patterns.

How does the speech of Turkish speaking phonologically disordered children differ from that of

children speaking other languages?

The PD children’s error patterns can be sub-classified as proposed in the literature for

other languages as shown in Table V. The present study presents evidence concerning

universal patterns of development as well as speech disorders. The results of the Turkish

normative data suggests that the order of acquisition is stops.nasals.affricates.glides/

liquids.fricatives.flap. Although acquisition of stops and nasals follows a similar path

universally, in English fricatives are acquired earlier than affricates. However, in Turkish

and Cantonese affricates are acquired earlier than fricatives. Similarly, one of the more

common developmental patterns for English is stopping of affricates but for Turkish

stopping of fricatives especially for /s/ and /z/ was common. /s/ is acquired earlier than /s/,

i.e., palato-alveolar fricatives were acquired earlier than alveolar fricatives. So, it is not

surprising that the most problematic sound classes for PD children were the flap, fricatives,

affricates, and velars in that order. The results suggest that late acquired sounds were likely

518 S. Topbas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

Table V. Crosslinguistic comparison of the error patterns of the sub-groups of phonologically disordered children.

Turkish German English Cantonese Putonghua Puerto-Rican Spanish

Most frequent

developmental

error patterns

Liquid deviation Interdentally Final consonant Stopping Stopping Velar fronting

WF cluster reduction Fronting of plosives Deletion Deaspiration Gliding Stopping

Assimilation Fronting of sibilants Cluster reduction Final consonant Fronting of

sibilants

Palatal fronting

Metathesis Cluster reduction Weak syllable deletion Deletion Affrication Liquid simplification

Fronting Fronting of / / Reduplication Final glide deletion Assimilation

Voicing (SIWI andSIWW) Cluster assimilation Fronting of velars Cluster reduction Cluster reduction

Stopping Stopping Unstressed syllable

deletion

Consonant deletion Final consonant

deletion

Devoicing Initial consonant

deletion

Affrication

Syllable deletion

Backing

Most frequent unusual/

consistent and

inconsistent error

patterns

Stopping of liquids Backing of alveolar

/f/R/s/ or /h/

Backing Backing Backing and

stopping

Backing

Stopping of nasals Metathesis Initial consonant Vowel rule Final consonant Deaffrication

Nasalization of fricatives Intrusive Deletion Addition

Gliding of fricatives Consonants Medial consonant

deletion

Vowel change

Unusual metathesis Consonant Intrusive

(Least frequent) Deletion Consonants

Glottal stop insertion Allaphonic fricatives Medial consonant

Inconsistent velarization Favourite sound Substitution

Sound preference Cluster changes Denasalization

Lateralization Favourite sound

Inconsistent /h/ use

Adapted from Fox & Dodd, 2001; Bradford & Dodd, 1996; So & Dodd, 1994; Hua & Dodd, 2000.

Phon

ological

disord

erin

Turk

ishsp

eakers

519

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

to be problematic, whereas the highest mastery level was for stops, nasals, the glide and the

liquid /l/ and a moderate level for affricates.

When the severity levels are taken into account, it can be inferred that the children falling

into severity level 1 can be considered as showing delayed developmental processes. The

children in the second level also used delayed developmental processes but their frequency

was much higher and the children’s phonetic inventories were greatly restricted. Thus, a

total of 26 children, 37% in this study might be labelled as belonging to a delayed group.

Nineteen children who scored between 50–75% correct used unusual but consistent

processes as well as persisting ones. These children were labelled as being in the unusual

sub-group. Thirty-five per cent of children who scored below 50% showed error patterns

including delayed, unusual and variable, and were very unintelligible. These results are

compatible with the results of Fox and Dodd’s (2001) study of German, Bradford and

Dodd’s (1996) investigation of English, So and Dodd’s (1994) work in Cantonese, Hua

and Dodd’s (2000) and Hua’s (2002) research in Potunghua, and Goldstein’s (1996) study

of Spanish. Yavas and Lamprecht (1988) reported that two of the four phonologically

disordered children they analysed used unusual rules, whereas the other two used persisting

ones. Although there are shared error patterns among languages, there are differences as

well. For example, backing or metathesis is reported as a non-developmental process for

languages other than Turkish. While final consonant deletion is reported for other

languages, in Turkish deletions both post- and pre-consonantal within word were more

frequent. The liquids and the flap were subject to deletion in these positions in both ND

and PD children. Delayed error patterns were typical of normal children but were used with

high frequency, and support the literature that the difference between these groups was

quantitative in nature rather than qualitative (Hua & Dodd, 2000). In this study, children

who fell into this category also used persisting patterns more frequently than ND. Thus, we

can infer that the delayed PD children are sensitive to the structure of their native language

just as the ND children. The analysis covered the general descriptive aspects of the above

categories, to show the necessity of such sub-classifications, which have been reported for

ten subjects in a preliminary analysis as well (Kopkallı-Yavuz & Topbas, 1998). Further

analysis of qualitative aspects may capture more information regarding the similarities and

differences among languages, in a detailed future study. Nevertheless, it can be inferred

that the most frequent error patterns are dependent on the phonological structure of the

language. Although universal tendencies exist, the ambient language effect is apparent in all

languages. Some error types are observed as being very unusual and inconsistent for

Turkish. This might be reflected in the severity of speech errors. Any hypothesis underlying

deficits in these children will be vague for the present aim of this study, and will thus need

further research. However, since the age of the PD children was older than the ND,

classifying the error patterns in terms of surface errors has implications for clinical

treatment provision.

Acknowledgement

The author expresses her gratitude to our research assistants Bulent Togram and Barıs

Dincer and our graduate MSc Speech-Language Pathology students for their assistance in

data collection and transcription. This research has been aided by a grant from Anadolu

University Research Foundation project no. 006 and the Turkish Ministry of Education,

Department of Speech Disorders. Special thanks are due to the anonymous reviewer.

520 S. Topbas

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

References

Acarlar, F., & Ege, P. (1996). Turkce kazanımda kullanılan fonolojik sureclerin incelenmesi. (Phonological

processes in the acquisition of Turkish). Turk Psikoloji Dergisi, 38, 35–43.

Bradford, & Dodd, B. J. (1996). Do all speech disordered children have motor deficits? Clinical Linguistics and

Phonetics, 10, 77–101.

Dodd, B. (1993). Speech disordered children. In G. Blanken, H. Dittmann, H. Grimm, J. Marshall, & C. W.

Wallesch (Eds.), Linguistic disorders and pathologies (pp. 825–834). Berlin: De Gruyter.

Fox, A. V., & Dodd, B. (2001). Phonologically disordered German-speaking children. American Journal of Speech-

Language Pathology, 10, 291–304.

Goldstein, B. (1996). Error groups in Spanish-speaking children with phonological disorders. In T. W. Powell

(Ed.), Pathologies of speech and language: Contributions of clinical phonetics and linguistics (pp. 171–177). New

Orleans, LA: ICPLA.

Grunwell, P. (1985). Phonological assessment of child speech (PACS). Dorset: NFER-Nelson.

Hua, Z. (2002). Phonological Development in Specific Contexts: Studies of Chinese-speaking Children (pp. 106–120).

Clevedon: Multilingual Matters.

Hua, Z., & Dodd, B. J. (2000). Putonghua (modern Standard Chinese)-speaking children with speech disorders.

Clinical Linguistics and Phonetics, 14, 165–191.

Ingram, D. (2004). Phonological acquisition from a cross-linguistic perspective. Paper presented at ICPLA10, 26–

29 February, University of Louisiana, Lafayette.

Ketrez, F. N. (1997). Bir cocugun dil edinimi surecinde ses aktarımı. (The process of metathesis in the phonology

of a child acquiring Turkish) XIth Linguistics Symposium, 22–23 May, Middle East Technical University,

Ankara.

Kopkall1-Yavuz, H., & Topbas, S. (1998). Phonological processes of Turkish phonologically disordered children:

Language specific or universal? In W. Ziegler, & K. Deger (Eds.), Clinical Phonetics and Linguistics (pp. 88–97).

London: Whurr Publishers.

Kopkall1-Yavuz, H., & Topbas, S. (2000). Children’s preferences in early phonological acquisition: How does it

reflect sensitivity to the ambient language? In A. Goksel, & C. Kerslake (Eds.), Studies on Turkish and Turkic

languages. Harrassowitz Verlag: Wiesbaden.

Leonard, L. B. (1985). Unusual and subtle phonological behaviour in the speech of phonologically disordered

children. Journal of Speech and Hearing Disorders, 50, 4–13.

Shriberg, L. D., & Kwiatkowski, J. (1982). Phonological disorders I: A diagnostic classifiction system. Journal of

Speech and Hearing Disorders, 4, 226–241.

So, L. K. H., & Dodd, B. J. (1994). Phonologically disordered Cantonese-speaking children. Clinical Linguistics

and Phonetics, 8, 235–255.

So, L. K. H., & Dodd, B. J. (1995). The acquisition of phonology by Cantonese-speaking children. Journal of Child

Language, 22, 473–495.

Topbas, S. (1988). The frequency effect and the acquisition of /k, t, ts/ sounds in Turkish. Unpublished thesis,

City University, London.

Topbas, S. (1994). Konusma sorunlu cocukların sesbilgisel cozumleme yontemi ile degerlendirilmesi.

(Phonological analysis of speech disordered children). Unpublished doctoral thesis (pp. 150–250), Anadolu

Universitesi, Eskisehir.

Topbas, S. (1996). Sesbilgisi acısından dil edinimi (Language acquisition. A phonological approach). Dilbilim

Arastırmaları, 4, 118–128. Ankara: Hitit Yay.

Topbas, S. (1997). Turkish children’s phonological acquisition: Implications for phonological disorders. European

Journal of Disorders of Communication, 32, 377–397.

Topbas, S. (2004a). Does the phonology of Turkish-speaking children differ from children learning other

languages. Paper presented at ICPLA 10, 26–29 February, University of Louisiana, Lafayette.

Topbas, S. (2004b). Turkce Sesletim-Sesbilgisi Testi (Turkish Articulation and Phonology Test). Ankara: Milli

Egitim Yayınevi.

Topbas, S. (in press). A Turkish Perspective on communicative disorders. Logopedics Phoniatrics Vocology.

Topbas, S., & Dincer, B. (2002). Universal and language specific aspects of variability in phonological patterns.

IASCL-SRCLD Conference, 16–21 July, University of Wisconsin, Madison.

Topbas, S., & Konrot, A. (1998). Variability in phonological disorders: Can we search for systematicity? Evidence

from Turkish-speaking children. In W. Ziegler, & K. Deger (Eds.), Clinical Phonetics and Linguistics (pp. 79–87).

London: Whurr Publishers.

Topbas, S., & Kopkall1-Yavuz, H. (1998). The onset of a linguistic system: Is there evidence from the acquisition

of final devoicing in Turkish? In A. Sorace, C. Heycock, & R. Shillcock (Eds.), Proceedings of the GALA

Phonological disorder in Turkish speakers 521

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.

Congress (Generative Approaches to Language Acquisition Conference) (pp. 284–289). Edinburgh:

Edinburgh University Press.

Topbas, S., & Yavas, M. (2006). Phonological acquisition and disorders in Turkish. In Z. Hua, & B. Dodd (Eds.),

Phonological development and disorders in Turkish: A multilingual perspective (pp. 233–264). Clevedon: Multi-

lingual Matters.

Yavas, M., & Lamprecht, R. (1988). Processes and intelligibility in disordered phonology. Clinical Linguistics and

Phonetics, 2, 329–345.

Yavas, M., & Topbas, S. (2004). Liquid development in Turkish: Salience vs. frequency. Journal of Multilingual

Communication Disorders, 2, 110–123.

522 Phonological disorder in Turkish speakers

Clin

Lin

guis

t Pho

n D

ownl

oade

d fr

om in

form

ahea

lthca

re.c

om b

y A

nado

lu U

niv.

on

09/2

4/12

For

pers

onal

use

onl

y.