This study compared wireless Contralateral Routing of Signals (CROS) hearing aid and bone-anchored hearing device (BAHD) in patients with single-sided deafness.
Eight adults with single-sided deafness previously implanted with a BAHD were given a 2-week trial with a CROS hearing aid and tested in unaided and aided conditions. Both devices were compared on head shadow effect reduction, speech perception measures in quiet and in noise, self-assessment questionnaires, and daily diaries.
Both the CROS and BAHD significantly reduced the head shadow effect. QuickSIN scores were significantly better with noise presented to the poorer ear, as compared to the better ear, for the unaided condition, the BAHD, and the CROS. Scores showed no significant differences between the CROS and BAHD with noise presented to the better ear, but scores with the CROS were significantly poorer than in the unaided condition with noise presented to the poorer ear. There were no significant differences between BAHD and CROS for the ratings on the Bern Benefit in Single-Sided Deafness and Speech Spatial Qualities questionnaires. Both devices were worn an average of 10 hours per day. Four participants preferred the CROS for sound quality; three preferred the BAHD for comfort.
Comparisons of CROS and BAHD need to be re-evaluated as both technologies have evolved. In our pilot study, both devices seem comparable, with the CROS avoiding the risks of surgery, and we recommend a trial of CROS in our center for first line treatment of single-sided deafness.