Abstract:
Hypernasality is one of the core speech characteristics observed in the speech of children with repaired cleft lip and palate. One-third-octave analysis has been considered as a potential tool to measure acoustic correlates of hypernasality in the speech of individuals with RCLP. However, the acoustic characteristics of speech are influenced by the contextual effects. Hence, the present study aimed to find out the difference in one third octave spectral amplitudes of vowel /i/ across various contexts in children with RCLP and typically developing children. A total of 24 participants (12-RCLP, 12-TDC) in the age range of 4-12 years were considered for the study. The speech sample recorded included repetition of isolated vowel /i/ and vowel /i/ in the phonetic context of /pit/ and /tip/. The one third octave spectral amplitudes were measured for all the stimuli and compared across the groups using MATLAB. The results indicated that energy concentration over one third octave spectrum was more in RCLP group for stimulus /i/, /pit/, & /tip/ as compared to control group. The spectral energy at low frequencies (97Hz, 125Hz and 157.5 Hz) of the isolated vowel /i/ demonstrated a significant increase in spectral energy in RCLP than the control group. The study also reported higher spectral amplitudes for vowel /i/ in the context of /pit/ and /tip/ across frequencies as compared to the spectral amplitudes of isolated vowel /I/ across the groups. The differences were attributed to the influence of phonetic context on the spectral amplitude of vowel /i/