Variability in Voice Fundamental Frequency of Sustained Vowels in Speakers With Sensorineural Hearing Loss

In a previous study, the low-frequency modulation extent (LFP) of the vocal fundamental frequency (F0) showed a significant increase in the presence of binaural noise masking for the healthy individuals. This study was to investigate the F0 of subjects with sensorineural hearing loss (SNHL) using sustained phonations to explore the changes of F0 modulations in SNHL. Twenty-three SNHL subjects and 14 age-matched subjects without hearing loss were enrolled in the study. Sustained vocalizations of vowel /a/ for more than 5 seconds were digitally recorded. The F0 contour of each phonation was acquired using digital signal processing. The modulation extent at different frequencies was obtained using Fourier transformation of F0 contour. The LFP of F0 (<3 Hz) was significantly greater for the SNHL subjects (P < 0.001, independent samples t test). Although the correlation analysis was limited to the auditory-evoked brainstem response (ABR) thresholds because of their disagreement with the pure-tone thresholds in some subjects with functional hearing disorder, the correlation between LFP and ABR thresholds was significant (ρ = 0.45, P = 0.03, Spearman's correlation analysis). The LFPs of F0 were significantly greater for the SNHL subjects and the changes of F0 modulations could be detected using power spectral analysis of F0. The method may be used for evaluation of audio-vocal feedback in SNHL.