Patient-reported outcomes and speech-in-noise performance with OSIA versus other transcranial devices in unilateral and asymmetric hearing loss.

INTRODUCTION: Single-sided deafness (SSD) and asymmetric hearing loss (AHL) impair binaural hearing, reducing speech-in-noise perception, sound localization, and quality of life. Treatment options include bone conduction devices (BAHA, Bonebridge, OSIA) and CROS/BICROS hearing aids. The OSIA system is the most recent option, but comparative real-life data, particularly on patient-reported outcomes, remain scarce. This is the first study to assess the OSIA system in SSD and AHL patients using the Bern Benefit in Single-Sided Deafness (BBSS) questionnaire. METHODS: We retrospectively analyzed SSD and AHL patients who completed a trial with a transcranial device or CROS/BICROS, followed by implantation or fitting. Speech-in-noise performance (signal-to-noise ratio, SNR) and BBSS scores were collected at the end of the trial and at 4 months. Outcomes were compared across device groups, and correlations between objective and subjective measures were explored. RESULTS: At 4 months, OSIA users reported higher BBSS scores, but similar differences were already observed at the end of the trial, despite identical headband testing. This suggests an influence of patient expectations or profiles rather than device-specific effects. Music perception improved between trial and follow-up in OSIA and BAHA users. SNR gains correlated with several BBSS items at the end of the trial but not at 4 months. Overall, BBSS scores remained stable over time. CONCLUSION: All transcranial devices yielded early and sustained subjective benefit in SSD and AHL. OSIA users reported higher perceived benefit, though baseline differences may explain this. BBSS stability suggests benefit is established early and not strongly influenced by device technology.