Long Term Voice Effects of Partial Deafness Cochlear Implantation

Partial deafness (PD) causes a deprivation in hearing high frequencies. This leads to voice functional voice disorders. Study shows that PD is associated with changes in frequency, amplitude, noise, tremor, and voice irregularities. Partial deafness cochlear implantation (PDCI) has been proven to improve voice quality. The aim of the study was to evaluate the long-term voice effects of PDCI on voice. Voice samples of 16 adult bilaterally PD patients were analyzed 72 months after one-sided PDCI and compared to the results obtained 9 months after the procedure. Results showed that the improvements of acoustic parameters continued over time after the PDCI. The main improvements were noticed in terms of frequency and amplitude. Compared to short-term analysis, most of the parameters decreased more in long-term observations, and more of them achieved statistical significance (smoothed pitch perturbation quotient, fundamental frequency variation, relative average perturbation, shimmer in decibels, shimmer percent, amplitude perturbation quotient, smoothed amplitude perturbation quotient, peak amplitude variation). Parameters of noise also decreased (noise-to-harmonic ratio, soft phonation index) as well as those representing irregularity in voice (degree of unvoiced) and subharmonics parameters (number of subharmonics, degree of subharmonics). Thus, we concluded that the vocal benefits of PDCI are better the longer the patient uses a cochlear implant.