The Effects of Vocal Loudness on Nasalance Measures of Normal Adults

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This study examined the effect of vocal loudness on nasalance measures, under the conditions of three sentence patterns (i.e., Oral sentences, Mixed sentences, Nasal sentences). The vocal loudness level was classified into soft voice (55 dB), medium voice (65 dB) and loud voice (75 dB). The participants in the present study were 30 normal adults (male: female =1:1). Kay's Nasometer 6200 was used to measure nasalance and Sound level meter was used to adjust the loudness level. The results of the present study are as follows. Firstly, the change in vocal loudness is in the following. In the Oral sentence stimuli, the loud voice for both male and female showed the highest nasalance degree, and the medium voice the lowest level. In the Mixed and Nasal sentence stimuli, however, male participants showed the highest degree of nasalance in the soft voice, and the lowest degree in the loud voice, and female showed the highest degree of nasalance in the soft voice and the lowest in the medium voice. Secondly, when each subject's nasalance scores were ranked in a ordered manner, noticeable tendency. Lowest nasalance score occurred in the loud voice and the highest nasalance score was recorded in the soft voice during participants' reading of the Nasal sentences. However, it was hard to find such pattern in the Oral sentences. It is assumed that velopharyngeal function could be related to these findings. Furthermore, the findings associated with vocal loudness may have diagnostic as well as clinical implications.