Better Performance With Bone-Anchored Hearing Aid Than Acoustic Devices in Patients With Severe Air-Bone Gap

Objectives/Hypothesis: A study performed in the 1990s with analogue linear hearing aids showed that in patients with mixed hearing loss and an air-bone gap that exceeded 25 to 30 dB, speech perception was better with a bone-anchored hearing aid (Baha) than with a conventional behind-the-ear (BTE) device. The objective of the present study was to investigate whether this conclusion applies to today's digital BTEs with feedback cancellation and whether the crossover point still occurs at an air-bone gap of 25 to 30 dB. Study Design: Case control. Methods: Experienced unilateral Baha users with the latest digital Baha processors were fitted with a powerful BTE with feedback cancellation. After an acclimatization period of 4 weeks, aided thresholds and speech recognition scores were determined and compared to those recorded previously with the Baha. To obtain patients' opinions, a disability-specific questionnaire was used. Participants comprised 16 subjects with bilateral mixed hearing loss participated. Results: Audiometric and speech recognition data showed similar trends to those described previously, but the crossover point had shifted to an air-bone gap of 30 to 35 dB. In the questionnaire, the BTE was rated higher than the Baha, except by the patients with an air-bone gap that exceeded an average of 45 dB. Conclusions: In patients with mixed hearing loss whose air-bone gap exceeded 35 dB, speech recognition is likely to be better with a Baha than with a BTE. Therefore, the Baha should receive greater consideration when mixed hearing loss is combined with a significant air-bone gap, even when there are no contraindications for BTEs.