Fundamental frequencies in 953 cleft palate with hypernasality over the past 10 years

Abstract

Phonetic research on hypernasality must be made from various viewpoints including resonance, vocal intensity and pitch (fundamental frequency). The authors have conducted various studies on each of these areas. In the present research, they investigated the pitch factor on the basis of 953 randomly selected cleft palate patients, ranging from 4 to 9 years of age, who visited our university clinic over the past 10 years. Fifty-six normal subjects, aged 4 to 6 years, served as the control.
A frequency analysis was conducted by sound spectrography on the phonation of the isolated vowel soun ds / a/ and / i/. When the fundamental frequency was measured, results showed no correlation between the degree of hypernasality and the pitch with either /a/ or /i/ vowels. However, a slight difference was found only with the vowel / i/ between the fundamental frequencie s of cleft palate patients and the control.