Contralateral Routing of Signal in Unilateral Cochlear Implant Users

Bilateral profound sensorineural hearing loss (PSNHL) is often treated with Cochlear Implants. The majority of bilaterally deafened patients, however, often only receive a unilateral cochlear implant (CI), with resultant limitations related to monaural listening. For unilateral CI users, the deficits inherently associated with monaural listening remain despite the considerable benefits achieved through implantation. Providing bilateral input to monaural listeners (MLs) overcomes some of these disadvantages. Treatment by contralateral routing of signal (CROS) hearing aids, where the signal of interest is routed from the impaired (deaf) ear to the normal cochlea for processing is a promising alternative in unilateral CI recipients who cannot benefit from bilateral CIs. Utilizing CROS technology provides a less invasive alternative for patients who are unable or unwilling to undergo a second CI surgery and offers an innovative approach to resolving the auditory deficits associated with monaural listening. CROS technology has been used to treat traditional monaural listeners since 1965. When applied to unilateral CI users, this novel approach can overcome a key limitation of current treatment by restoring access to sound from the non-implanted ear and improving speech perception in noise.