Strategies used by children with typical and atypical phonological development during the blocked syllable acquisition

Purpose: to study the use of repair strategies by children with typical and atypical speech development through an analysis guided by the syllable from a target with simple coda. Methods: speech data from 24 children with typical speech development and from 12 children with atypical speech development were analyzed. The children’s ages were between 1:0 and 4:0 and between 4:1 and 7:0, respectively. The analyzed dependant variable included the following syllabic variants: syllable omission, coda omission, epenthesis, metathesis, and coalescence. The statistical analysis was accomplished through the use of the Statistical Program VARBRUL. Results: it was possible to verify the use of repair strategies such as coda omission, coalescence, epenthesis, and metathesis in the children with speech disorders. The group with typical speech development presented higher occurrence of syllable omission. The variable age was significant for coda omission. When observing the variable sex, the girls with atypical speech development seem to use repair strategies more frequently, while the boys omit coda more often. Both groups tend to preserve the word final position. The extrametrical positions were more favorable for coda omission in the group with atypical speech acquisition. The post-stressed position is more favorable for coda omission and the stressed position is favorable for syllable omission in the group with typical development. Conclusion: the groups used different repair strategies during the blocked syllable acquisition. The group with typical acquisition prefers to omit the syllable, while the group with phonological disorders used the other analyzed repair strategies.

neurological, psychological or cognitive alterations.Besides, the parents and/or responsible for the children authorized, through Informed Consent term, the use of the speech samples of their children in researches about language and speech acquisition and development.
For both groups, it was performed speechlanguage screening, including language, voice, orofacial motricity evaluation and auditory screening 12 .To collect the data, the used instrument was the Children Phonological Assessment -CPA, through which it was possible to observe and to evaluate all present phonemes and syllables of Brazilian Portuguese 8 .
In this study, it will be referred data about the repair strategies, not the correct production of the blocked syllable.
The considered intervenient variables were: • Age: age group from 1:0 to 3:11;29 for typical data and from 4:0 to 6:11;29 for the atypical data, with intervals of six months.
• Gender: female and male.
The blocked syllabic structure, formed by consonants, is one of the last structures to be acquired during the period of language acquisition.It occurs because of its level of complexity.Based on performed studies, in Brazilian Portuguese, the acquisition of syllabic structures happens in the following order: V, CV > CVV à CVC à CCV [5][6][7] .
Regarding the acquisition of syllable structures, the theoretical perspective from the natural phonology recognizes the following repair strategies: cluster reduction, omission of non-stressed syllable, omission of final fricative, omission of final liquid, omission of liquid between vowels, omission of initial liquid, metathesis and epenthesis 8 .
Several researches had the purpose of verifying the intervenient variables during the acquisition of the segment which is in the coda position, by children with typical phonological development 4,9,10 .Considering the syllabic complexity of the blocked structure, it is believed that intervenient factors may influence the hold of this structure 1,11 .Those intervenient factors, which are detailed and exemplified in the method may be linguistic (tonicity, number of syllables, precedent phonological context, following phonological context, word position, complexity of the syllable onset, segmental complexity of the coda element, position of the (C)VC syllable in relation to the metrical foot, type of phonological development) and extralinguistic (gender and age).
However, such aspects were not investigated yet, because researches focus mainly the study of segmental acquisition, not syllabic acquisition.Because of this, it is important to perform this study, which has the purpose of studying and comparing how children with typical and atypical phonological development use repair strategies through a syllable guided analysis (phonology and acquisition basic unit) in targets with simple coda.

METHODS
The speech data of the sample were selected from two data bases of a university.The research projects were approved by the Research Ethics Committee, n. 052/2004 and 064/2004.
To perform this study, the sample consisted of two groups, the first with children with typical phonological acquisition (24 children) and the other group with phonological disorder (12 children), with ages from 1:0 to 4:0 and 4:1 to 7:0, respectively.This age difference between the groups occurred because it is only possible to diagnose the phonological disorder in children with more than four years old 3 .
As inclusion criterion, the children who participated in this study could not receive or be receiving speech-language therapy; neither present atypical development.These words are related to the blocked syllable production, which were categorized through a form at Microsoft Access.Then, it was performed an analysis through the Statistical program VARBRUL in Windows environment -Varbwin, with 5% margin of error.The VARBRUL performs probabilistic analysis in binary way, designating relative weighs (probability).The relative weighs or probabilities of repair strategies occurrence regarding blocked syllables come from statistical interaction.Values with relative weigh under .50ware considered as unfavorable to the analyzed item, probability numbers from .50 to .59 were considered as neutral and values equal or above .60were considered as favorable.

RESULTS
The results obtained through this study showed that there is higher frequency of use of repair strategies such as coda omission, metathesis and syllable omission by children with phonological disorder.About the group with typical phonological acquisition, it was detected higher frequency of coda and syllable omission.
• Type of phonological development: typical or phonological disorder.
It is useful to emphasize that in Brazilian Portuguese (BP), the metrical foot refers to the way the accents are attributed.Authors refer that the BP presents a syllable-timing, which is a binary foot with the head (strong syllable of the foot) with predominance to the left.The paroxytone pattern accent in BP is presented by the metrical foot and this mapping occurs from the right to the left, and it can be sensitive to the syllabic weigh 13 .
It was obtained a corpus with 2029 words, 1033 from the typical development and 996 from the  favorable -from 1:0 to 2:6, while in the group with atypical development the intermediate age groups -4:6 to 5:6 -are the most susceptible to coda omission (Table 1).
Besides, when analyzing the extralinguistic variables which influenced the coda omission, it was perceived that in the group with typical phonological acquisition the initial age groups are the most In relation to the variable gender, girls with phonological disorders seem to use more repair strategies -coda omission -than boys with this impairment, because in the group with typical acquisition the boys are more favorable to the analyzed item (Table 1).
Regarding the variable tonicity, this item was selected only for the group with typical acquisition, with the post-tonic position as favorable for coda omission.
About the word position, this item seems to act in a similar way for both groups, because the final position tends to be the most preserved, not being target for omission (Table 1).
In relation to the onset complexity, only for the group with typical acquisition the structure simple onset was the most favorable for coda omission.About segment complexity, the nasals and laterals were the most preserved in both groups.They were less probable to be omitted, with low relative weighs (Table 1).
Regarding the metrical foot, this item was selected only for the group with atypical acquisition.The extrametrical positions are the most favorable for coda omission (Table 1).
Considering the syllable omission, it was evidenced that the typical group suffers more the omission, while the tonic position is favorable for syllable omission.Moreover, for syllable omission the age was a relevant factor for the group with typical acquisition, and the initial age groups (1:6 to 2:6) are the most favorable for this item (Table 2).
influences of the studied variables, as it is observed in Figure 2.
The variable tonicity was selected only for the group with typical phonological development.The post-tonic position is favorable for the coda * Statistical analysis: Statistical program VARBRUL (p< 0.05) Agreeing with the literature 1 , the fricative and non-lateral liquids sound classes are the most favorable for coda omission in phonological disorders.In the group with typical acquisition, only the non-lateral liquid was favorable for this item.

Figure 2 -Probability of occurrence of coda omission and syllable omission
Regarding the metrical foot, this variable was selected only for the group with phonological disorders, in which it was detected that the extrametrical positions are the most favorable for coda omission, agreeing with studies performed with subjects with verbal dyspraxia, in which the head of the metrical foot also tends to be preserved 20,21 .
In relation to the syllable omission, some items were similar to the coda omission, such as the age, which also influences the group with typical acquisition, acting in a similar way.In this case, the initial age groups are the most favorable for omission 4,10 .
It disagrees with literature [4][5]22,23 , in which the syllable that presents the accent in Brazilian Portuguese usually favors the articulatory precision because of stronger acoustical characteristics. In ths study, the tonic syllable was favorable for syllable omission in the group with typical acquisition.In relation to the metrical foot for the same group, the "head" was preserved, because it is unfavorable for syllable omission, while the syllable which is out of the metrical foot was favorable for omission.
Besides, as it is observed in figure 2, it was verified that there is higher probability that the group with typical acquisition omits the syllable, while the group with atypical acquisition favors coda omission.It may happen because individuals with typical acquisition belong to initial age groups, omitting the syllable, while the subjects with disorders, because they are older, they express better phonological knowledge 24,25 when they preserve the syllable and omit the coda.
The results of this research may help the diagnosis between the groups, because there were differences between the strategies used by children with typical and atypical acquisition.Moreover, the findings from this study may help the choice of targets to be worked in Speech-language therapy, shortening the time of treatment.It must be emphasized the individual variability, as the data presented in this study used with care in evaluation and speech-language therapy.Also, this study is restricted to the variant spoken in the south of Brazil.Other researches should be performed in different parts of the country.

CONCLUSION
According to the results of this study, it was verified that children with typical phonological development seem to use different repair strategies when

DISCUSSION
In Figure 1 it was possible to verify that there are similar repair strategies used by the group with typical as by the group with atypical acquisition.It agrees with literature which mentions that it is possible observe similar strategies for both groups 14,15 .
Regarding the repair strategy coda omission, it was detected that the age is statistically significant for this item.The group with typical acquisition in the initial age groups is the most favorable and also the group with phonological disorders in intermediate age groups.These results seem to agree with literature, because the probability of using coda is higher as children get older.Some transitory decreases are possible during its production 4,10 .
Besides, the variable gender also influences the coda omission, because in phonological disorder girls are more susceptible to use this repair strategy.This fact agrees with studies in which boys with phonological disorders presented better results in metalinguistic abilities 16,17 .In the group with typical acquisition, boys are more favorable for coda omission, what agrees with a study in which boys with typical phonological development presented a tendency of phonological precision, with higher probabilities of coda correct production 10 .
The syllable tonicity favors the completion of the coda position, by the segments which may occupy such position in typical phonological development 4,9 , agreeing with data obtained in this study about coda omission, because for this same group the tonic syllable is the most preserved for this item.
About word position, the initial positions in both groups are the most favorable for coda omission, agreeing with other studies, because even for the coda acquisition, the final position is first acquired because it is a more salient and marked structure 18,19 .According to the results obtained in this study, this position tends to be more preserved as well.
In relation to onset complexity in the group with typical acquisition, the structure simple onset was the most favorable for coda omission, agreeing with literature, because this is one of the first structures to be acquired 5,7 .As the nasal as the lateral sound classes were the most preserved regarding the use of repair strategies in both groups, because they are also the first structures to be acquired.When it is observed the emergence of the segments which are in coda, it is detected that the lateral liquid is the first to emerge in final position, when children are 1:2 11 .This evidence reinforces the results obtained in this study about the acquisition of the blocked syllable and its word position.female gender favors this same item for the group with atypical acquisition.Also about coda omission, the tonicity influences the group with typical acquisition and the tonic syllable is the most preserved, as well as the metrical foot is significant for the group with atypical acquisition.In this case, the extrametrical syllables are the most favorable for coda omission.The segmental complexity acts in a similar way for both groups, because the non-lateral liquid is the most favorable for coda omission.
In relation to syllable omission, the variables were significant only for the group with typical acquisition.
It shows that this speech pathology may be characterized more as a medium disorder of phonological development than as a linguistic disorder.compared with children with phonological disorders through an analysis guided by the syllable.While there is higher probability that the group with typical acquisition omits the syllable, the group with atypical acquisition presents more significant probability of omitting the coda.

*
Statistical analysis: Statistical program VARBRUL (p< 0.05) **For this study, the correct production was not considered

Figure 1 -
Figure 1 -Frequency of repair strategies

Table 2 -Variables selected in the repair strategy syllable omission
* Statistical analysis: Statistical program VARBRUL (p< 0.05)