A Randomized Crossover Study in Single-Sided Deafness Comparing a Cartilage Conduction CROS System and an...

Area of Science:

• Audiology
• Hearing Science
• Biomedical Engineering

Background:

• Single-sided deafness (SSD) presents significant challenges in hearing, particularly in noisy environments and with sound localization.
• Contralateral routing of signals (CROS) hearing devices aim to improve hearing for SSD patients by transmitting sound from the unaidable ear to the hearing ear.
• Cartilage conduction (CC) rerouting devices offer an alternative to traditional air-conduction (AC) CROS devices.

Purpose of the Study:

• To compare the noninferiority of cartilage conduction contralateral routing of signals (CC-CROS) devices versus air-conduction CROS (AC-CROS) devices in single-sided deafness (SSD) patients.
• To evaluate objective and subjective performance metrics in realistic listening conditions.

Main Methods:

• A prospective, single-subject randomized crossover study was conducted with nine adults with severe to profound unilateral sensorineural hearing loss.
• Patients used both CC-CROS and AC-CROS devices for two weeks each in a randomized order.
• Outcomes included speech-in-noise tests (speech reception threshold), sound localization accuracy, and subjective questionnaires (APHAB, SSQ-12).

Main Results:

• Both CC-CROS and AC-CROS significantly improved speech reception thresholds in ambient noise when speech originated from the front or the unaidable ear side.
• AC-CROS showed a significant benefit when speech came from the better ear side, while CC-CROS did not.
• Sound localization was generally worsened by both devices, but subjective measures (APHAB, SSQ-12) indicated perceived benefits from both CC-CROS and AC-CROS.

Conclusions:

• CC-CROS devices demonstrate noninferior hearing-in-noise performance compared to AC-CROS devices, with the exception of speech presented to the better ear in ambient noise.
• Subjective assessments confirmed that patients recognized the effectiveness of both CC-CROS and AC-CROS devices in improving their hearing experience.