Comparative Mapping of Vocal Parameters in Auditory Neuropathy Spectrum Disorder with and Without Use of Speech Processor in Bilateral Cochlear Implantation - A Pilot Study

Cochlear implantation (CI) in auditory neuropathy spectrum disorder (ANSD) is considered as optimal treatment option who gets limited or no benefit from conventional devices which includes assistive listening devices as well. Prime characteristic feature in ANSD is poor speech discrimination and reduced speech intelligibity in presence of background noise. Effectiveness of analysis of deviant vocal parameters is important due to increase in auditory feedback and subsequent voice quality. This study is done in 11 -year -old female with ANSD, who had been implanted bilaterally with implant age of 1.5 years was participated. Vocal parameters including sustained and interrupted phonation, glides, and soft and loud phonation were recorded during 5 -hour intervals with the speech processor both on and off condition. Later, these samples were analyzed using PRAAT software. Acoustic Analysis revealed significant increment in the frequency dynamicity Fo in ON condition. Significant difference in the pattern of attenuation of higher formants is noted. Though assistive listening device and hearing aids play major role in late onset group, comparison of data with expanded version of study with large samples in assessing vocal parameters specific to post bilateral CI with respect to late onset group will helps surgeon and audiologist to arrive at a decision making of possible candidacy criteria followed by rehabilitation process. Future direction is to predict the minimum time period of off periods which has effect on auditory deprivation due to reduced usage of auditory feedback.