The present aims to understand the acoustic characteristics of speech rate and pauses of autistic children and to provide basic data for language education for them by analyzing their speech in comparison to those of normal children. For this pu...
The present aims to understand the acoustic characteristics of speech rate and pauses of autistic children and to provide basic data for language education for them by analyzing their speech in comparison to those of normal children. For this purpose, a reading experiment of 'Tiger Story' paragraph was conducted to each 10 autistic and normal children aged 9∼12 and their acoustic characters were put to analysis.
The results are as follows: First, it lasted 83.13 seconds in average for autistic children to read the paragraph, while it took normal children an average of 43.73 seconds to read the same. The average overall speaking rate of autistic children was 2.81 syllables/sec., normal children 4.41 syllables/sec., and the average articulation rate of autistic children was 3.97 syllables/sec., normal children 4.80 syllables/sec., with autistic children being slower in both speech rates than normal ones.
Second, autistic children had an average of 53.39 seconds of pauses between sentences while normal children an average of 3.39 seconds, and autistic children had 3.11 seconds in average of pauses within a sentence while normal children 0.43 seconds in average. Autistic children turned out to take longer time in both pauses between and within sentences. The autistic children also had an average of 3.56 pauses within a sentence, more frequent than 1.10 pauses in average of normal children.
Third, the correlation analysis by group between children's receptive․expressive vocabulary test scores and their speech characteristics showed that both children groups revealed a high correlation between vocabulary test scores and speech rate-related characters such as paragraph duration, overall speaking rate and articulation rate. In case of autistic children, their vocabulary test scores showed a mild correlation with pause duration within a sentence and pause frequency but no correlation with pause duration between sentences. Normal children featured not high but significant correlation between all three pause characters and receptive and expressive vocabulary scores.
Fourth, the correlation analysis by group between the number of syllables within a sentence and their speech characters showed that in both children groups, the number of syllables within a sentence had a high correlation with length of sentences and significant but not strong correlation with pause frequency and pause duration within a sentence. The autistic children group didn't indicate any significant correlation in overall speaking rate and articulation rate, whereas, however, overall speaking rate of the normal children group showed weak but significant correlation with number of syllables but articulation rate didn't show any significant correlation.
In sum, the autistic children group were found to have slower overall speaking rate and articulation rate and more frequent and longer pauses than the normal children group. It was also evident that the higher the receptive and expressive vocabulary scores of autistic children are, the faster speech rate, the shorter pause and the lower frequency of pause the autistic children group featured compared to the normal children group. Both children groups showed longer sentence duration, more frequent pauses and longer pause as the number of syllables within a sentence increases, but no significant correlation with articulation rate, clearly demonstrating the typical features of the syllable-timed language in Korean.
The findings of the present study are almost equivalent to the preceding studies which confirmed that the older the age of language development progresses, the faster the speech rate, the shorter the pause duration and the lower the frequency of pause becomes. The results of this study verifying the lower articulation rate of autistic children are, however, opposed to those of the preceding study of Jeong & Seong (2007) on the articulation rate of autistic children. To determine whether such difference in the two studies comes from different experimental processes or from difference in characters of the autistic children group, it is needed to assign to autistic children more diversified tasks like dialogues, spontaneous speech, etc. or to perform further studies on the autistic children group with other characters. It may also be said that these results imply indirectly the needs that paragraph-reading task as well as sentence-reading task should be performed as language therapy services for autistic children to promote accuracy and intelligibility of their production. To meet these requirements, it is requested to intensify training for children's reading by using diversified contents, length and degree of difficulties of their reading materials.
Lastly, this study can be said to be meaningful in that it furnishes objective and quantitative fundamentals for such characters as speech rate and pauses of autistic children through an acoustic analysis. Future studies should, in my opinion, focus on setting up more acceptable basis for speech characters of autistic children by analyzing other prosodic features like intonation, pitch and, loudness, length of speech, in addition to speech rate and pauses, collecting spontaneous speech samples in daily life together with reading tasks and by securing a sufficient number of subjects for experiment who can be formed as a homogeneous group in terms of age, language development and grade of handicap as autistic children.
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