Effectiveness of Channel-Free Hearing Aid and Noise Desensitisation Training in Auditory Neuropathy Spectrum Disorder - Single Case Study

Abstract

Auditory Neuropathy Spectrum Disorder is a rare condition wherein neural transmission through the VIIIth nerve and auditory brainstem is disrupted with intact peripheral hearing. Most frequently reported symptoms by individuals suffering from such conditions include impaired speech discrimination especially in presence of background noise. The aim of this single case study is to emphasize the effectiveness of channel-free technology as a rehabilitative option and to demonstrate the improvement in speech perception in noise with noise desensitisation training. A 24-year-old male patient reported to the National Institute of Speech and Hearing with the complaint of poor speech comprehension. The audiological profile revealed, bilateral moderate sensorineural hearing loss in pure tone audiometry with poor speech discrimination scores, bilateral ‘A’ type tympanogram with absent acoustic reflexes, good signal to noise ratio in otoacoustic emissions, and absent Auditory Brainstem Response at 95 dBnHL bilaterally suggestive of auditory neuropathy spectrum disorder in both the ears. As a part of rehabilitation, hearing aids with multiple channels and channel-free technology were tried and better speech discrimination scores were obtained with channel-free technology. In order to address poor speech discrimination in presence of noise, noise desensitisation training was given at different Signal to Noise Ratio with channel-free hearing aids and was found to be effective in improving the speech discrimination scores especially in adverse listening conditions.