Does nasal obstruction affect the articulation of plosive consonants?

Abstract

In this study, we investigated the impact of chronic nasal obstruction on articulation of the Turkish voiceless plosive (stop) consonants and examined the effect of the nose- and mouth-breathing on the articulatory characteristics of the specific speech sounds. Twenty-one controls with nose-breathing and 20 patients with mouth breathing were included in this study. The nasal obstruction history of the patients was 10 to 22 years. In the mouth-breather group, intranasal pathologies except septal deviation and turbinate hypertrophy were excluded. The nose-breather subjects without nasal pathologies served as the control group. The subjects graded nasal obstruction through visual analog scale (VAS) from 0 to 10. The minimal cross-sectional area (MCA) and minimal cross-sectional volume (MCV) at the level of septal tubercle and the head of inferior turbinate were established to be 1 and 2 by acoustic rhinometry. Minimal cross-sectional volume was defined as the volume below the curve. The syllables [pa], [ta], [ka] uttered by the subjects were recorded for the spectrographic analysis. Voice onset time (VOT) was measured on wide-band spectrogram. The VOT value of /p/ was found lower and the VOT values for /t/ and /k/ were found higher in mouth-breathers compared to nose-breathers, while the difference was not statistically significant. The right and left-sided VAS values of the nasal obstruction group were significantly higher compared to controls (p=0.001). The right and left-sided MCA1, MCA2, MCV1 and MCV2 were found statistically different between the two groups. It was concluded that the articulation features of plosive consonants were not significantly affected by nasal obstruction.