Benefit of Higher Maximum Force Output in Bone Anchored Hearing Systems: A Crossover Study.

Abstract

OBJECTIVE\nTo investigate how higher maximum force output (MFO) in bone anchored hearing systems (BAHS) affects perceived benefit and the subjective experience of sound as well as hearing outcomes in subjects with mixed hearing loss.\n\n\nSTUDY DESIGN\nProspective single-center, randomized crossover design (A-B-A) with within-subject control design.\n\n\nPATIENTS\nThe study included 19 experienced BAHS users with mixed hearing loss in the fitting range of a standard BAHS.\n\n\nINTERVENTIONS\nThe study evaluated two sound processors with differing MFOs and sizes-Device A: standard sound processor with a lower MFO and Device B: superpower sound processor with a higher MFO.\n\n\nOUTCOME MEASURES\nSpeech recognition in noise at different signal to noise ratios, aided thresholds, and questionnaires.\n\n\nRESULTS\nSpeech recognition test showed significant improvements using Device B compared with Device A at both 78\u200adB SPL (mean difference: 9%) and 75\u200adB SPL (mean difference: 12%) (p\u200a<\u200a0.05). Moreover, speech, spatial and qualities of hearing scale (SSQ12-C) showed a significantly greater perceived benefit with Device B concerning spatial abilities (mean: 0.5-0.6) (p\u200a<\u200a0.05). At the conclusion of the study, 58% of participants chose to keep Device A for further use. The main reasons for this were the size of the sound processor and a more comfortable sound experience.\n\n\nCONCLUSIONS\nA BAHS sound processor with a higher MFO leads to improved speech-in-noise performance in loud/noisy listening situations and is perceived as significantly better to process spatial information in daily listening situations. However, the relation between cosmetics and performance is not straightforward, and several factors seem to affect the selection process of BAHS.