title: Maximum duration of sustained /s/ and /z/ in children.
abstract: It has been proposed in the clinical literature that a ratio of the maximum duration of /s/ to /z/ may be useful in determining the possible contribution of the respiratory and vocal mechanisms to a disordered voice. The purpose of this study was to obtain preliminary normative data for the maximum phoneme duration (MPD) of /s/ and /z/ and to determine the ratio of /s/ to /z/ in five, seven, and nine year olds. The results indicated that while there were no significant differences in MPD for either /s/ or /z/ between males and females at any one age level, there was a significant increase in the MPD of /s/ and /z/ for both sexes as a function of age. When the ratio of /s/ to /z/ was computed for the subjects, there were no significant differences in these ratios between males and females nor were there significant differences as a function of age.
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010699:Phonation; D012016:Reference Values; D012737:Sex Factors; D014831:Voice; D014832:Voice Disorders / Q000175:diagnosis / Q000503:physiopathology