Spectral Characteristics of Cardinal Vowels as Indicators of the Auditory Speech Feedback Control in Patients with Moderate and Moderately Severe Chronic Postlingual Sensorineural Hearing Loss

Abstract

Chronic sensorineural hearing loss (SNHL) is characterized by an increase in hearing thresholds at basic speech frequencies, which implies the auditory speech feedback control worsening and, as a result, changes of speech characteristics. A hypothesis was tested that such worsening can manifest itself in an increase of F0, F1, F2 formants of speech vowel sounds in patients with moderate and moderately severe postlingual SNHL. Recordings of elicited speech were performed for young and middle age women (36–59 years): 7 women speakers with moderate SNHL who did not use hearing aids; 5 women speakers with moderately severe SNHL who were hearing aid users but were not using them during the recordings; a control group of 12 normally hearing women speakers. An assessment of F0, F1 and F2 of stressed vowels [a], [i], [u] and calculations of vowels’ centralization indices – vowel space area, vowel formant centralization ratio and the second formant ratio (F2i/F2u), were performed. All the studied spectral indices in groups of patients with postlingual SNHL were similar to those in the control group, no statistically reliable differences were revealed.