Acoustic Characteristics of Children of the Japanese Consonants [s] and [∫]

Abstract

The purpose of this study was clarify the acoustic characteristics of children of the Japanese consonants [s] and [∫], especially focused on the stage of missing deciduous incisors. The subjects 42 healthy children selected from the out patients and 7 males adults (control group).
And the children were divided into three groups by oral examination, Group A; with deciduous incisors fully erupted Group B; missing one or more deciduous incisors, and Group C; with all permanent incisors erupted.
The data speech waves of [s] [∫] uttered by 42 children and 7 males adults were analyzed with the cepstrum method. Analysis of the maximum frequency peaks was made for comparison among each groups. The results were as follows; The percentage with uncompleted speech [s] were more in Group A than in Group C. The average of maximum frequency peak for [s] of children groups showed high values in comparison with that of adult group. But there were no differences among the children groups. The maximum frequency peak data for [s] showed higher values than those for [∫]. The data of GroupB showed no difference from other children groups, so this result suggested that missing incisors has little influence upon the peak frequency of [s].