The effect of nasalization on /a/ vowel formants before and after nasal consonant in 4-9-year old normal Persian speaking children
Background and Aim: Nasalization of a vowel refers to the addition of nasal resonance to the vocal tract transfer function. Also, vowel nasalization occurs because of coarticulation. Coupling of the nasal resonating space to the oropharyngeal cavity alters the vocal tract formants in complex ways. The purpose of this study was to investigate the effect of nasalization on /a/ vowel formants in before and after nasal consonant.
Methods: In current cross-sectional study, voice samples of 60 normal children ranging the age of four-nineyears were investigated. Participants were asked to repeat /ʔama/ three times and vowel /a/ after presentation of an auditory model. Then, obtained samples were analyzed using Praat 5.3.13. Average of F0, F1, F2 and F3 were calculated for /a/ comes before and after /m/ in production of /ʔama/ over three trials.
Results: There were statistically significant differences of F1, F2 and F3 between /a/ which proceeds nasal consonant and /a/ follows nasal consonant, the before nasal consonant /a/ versus single /a/ and the after nasal consonant /a/ versus single /a/ (p=0.001 for all).
Conclusion: F1, F2 and F3 in /a/ before nasal consonant affected by anticipatory nasal coarticulation and in /a/ after nasal consonant affected by carry-over nasal coarticulation. This study showed nasal coarticulation and nasalization result in decreasing F1, F2 and F3 in /a/ vowel.
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