Comparison of Speech-in-Noise and Localization Benefits in Unilateral Hearing Loss Subjects Using Contralateral Routing of Signal Hearing Aids or Bone-Anchored Implants.

OBJECTIVE: To compare the benefit of wireless contralateral routing of signal (CROS) technology to bone-anchored implant (BAI) technology in monaural listeners.

STUDY DESIGN: Prospective, single-subject.

SETTING: Tertiary academic referral center.

PATIENTS: Adult English speaking subjects using either a CROS hearing aid or BAI as treatment for unilateral severe-profound hearing loss.

INTERVENTIONS: Aided performance utilizing the subjects BAI or CROS hearing device.

MAIN OUTCOME MEASURES: Outcome measures included speech-in-noise perception using the QuickSIN (Etymotic Research, Elkgrove Village, IL, 2001) speech-in-noise test and localization ability using narrow and broadband stimuli. Performance was measured in the unaided and aided condition and compared with normal hearing controls. Subjective outcomes measures included the Speech Spatial and Qualities hearing scale and the Glasgow Hearing Aid Benefit Profile.

RESULTS: A significant improvement in speech-in-noise performance for monaural listeners (p < 0.0001) was observed, but there was no improvement in localization ability of either CROS or BAI users. There was no significant difference between CROS and BAI subject groups for either outcome measure. BAI recipients demonstrate higher initial disability and handicap over CROS hearing aid users. No significant difference was observed between treatment groups for subjective measures of post-treatment residual disability or satisfaction.

CONCLUSIONS: Our data demonstrate that both CROS and BAI systems provide significant benefit for monaural listeners. There is no significant difference between CROS or BAI systems for objective measures of speech-in-noise performance. CROS and BAI hearing devices do not provide any localization benefit in the horizontal plane for monaural listeners and there is no significant difference between systems.