Effectiveness in Rehabilitation of Current Wireless CROS Technology in Experienced Bone-Anchored Implant Users

Objective: To compare the effectiveness of current contralateral routing of signal technology (CROS) to boneanchored implants in experienced bone-anchored implant users with unilateral severe-profound sensorineural hearing loss. Design: Prospective, within-subject repeated-measures comparison study. Setting: Tertiary referral center. Patients: Adult, English-speaking patients (n = 12) with severe-profound unilateral sensorineural hearing loss implanted with a bone-anchored implant for the indication of single-sided deafness. Intervention: Subjects were fitted with contralateral routing of signal amplification and tested for speech in noise performance and localization error. Outcome Measures: Speech perception in noise was assessed using the BKB-SIN test materials. Localization was assessed using narrow band noises centered at 500 and 4000 Hz, as well as a broadband speech stimulus presented at random to the front hemifield by 19 speakers spatially separated by 10 degrees. Results: There was no improvement in localization ability in the aided condition and no significant difference in performance with CROS versus bone-anchored implants (BAI). There was a significant improvement in speech in noise performance for monaural listeners in the aided condition for speech poorer ear/noise better ear, speech front/noise front, and speech front/noise back. No significant difference was observed on performance with CROS versus BAI subjects. Conclusion: Contrary to earlier studies suggesting improved performance of BAIs over CROS, the current study found no difference in performance in BAI over CROS devices. Both CROS and BAI provide significant benefit for monaural listeners. The results suggest that noninvasive CROS solutions can successfully rehabilitate certain monaural listening deficits, provide improved hearing outcomes, and expand the reach of treatment in this population.