The case for cochlear implantation in unilateral and asymmetric sensorineural hearing loss

Cochlear implants have been used to treat bilateral deafness for over 40 years. A more recent development has been the application of this technology toward single-sided deafness (SSD) and asymmetric hearing loss (AHL), culminating in the Food and Drug Administration (FDA) approval in the United States for this indication in July of 2019. This review examines the recent literature on cochlear implants for SSD and AHL, focusing on speech perception, sound localization, tinnitus, and quality of life.

There is an expanding body of literature supporting the use of cochlear implant in SSD/AHL patients. The cochlear implant offers a unique rehabilitation option for this subset of patients as it potentially restores binaural hearing (direct stimulation of both ears). A review of the literature reveals significant improvements with the cochlear implant in speech perception in quiet and noise, sound localization, tinnitus, and quality of life. In addition, these improvements appear to be greater than what conventional options such as a contralateral routing of signal (CROS) hearing aid and bone conduction device (BCD) are able to achieve.

Cochlear implants offer additional benefits over previously available options of CROS and BCDs and have recently been approved by the FDA for use in patient with SSD/AHL. Given the growing body of literature demonstrating the benefit of cochlear implant over other devices, it is important to offer cochlear implant as an option to these patients.