Maximum phonation time and s/z ratio in a large child cohort.
OBJECTIVE
The purpose of this study was to provide normal values for maximum phonation time (MPT) and the s/z ratio by examining 1660 children aged 4-12 years and without vocal signs or symptoms.


METHODS
The technique was based on the sustained emission of the /a/ vowel and fricatives /s/ and /z/.


RESULTS
The average of the MPT in children of the different age groups was as follows: 6.09 seconds for the age group 4-6 years (males, 5.97; female, 6.21 seconds), 7.94 seconds for the age group 7-9 years (males, 8.07; females, 7.79 seconds), and 8.98 for the age group 10-12 years (males, 9.05; females, 8.92 seconds). The overall average for males was 7.78 and females 7.64 seconds. The s/z ratio was near 1.0 in most children but above 1.2 in 133 children and below 0.8 in 133 children.


CONCLUSIONS
These values of MPT and s/z ratio can be used as normative in further pediatric studies.
Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Botucatu Medical School, São Paulo State University, São Paulo, Brazil.
Elaine Lara
EL
Mendes Tavares
Alcione G
AG
Brasolotto
Sérgio A
SA
Rodrigues
Adriana Bueno
AB
Benito Pessin
Regina Helena
RH
Garcia Martins
D000162:Acoustics; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010699:Phonation; D012016:Reference Values; D012737:Sex Factors; D013061:Speech Acoustics; D013068:Speech Production Measurement / Q000592:standards; D013997:Time Factors; D014831:Voice