Speech intelligibility with bilateral bone-anchored hearing aids: the Birmingham experience

Abstract

The Birmingham bone-anchored hearing aid (BAHA) programme, since its inception in 1988, has fitted more than 300 patients with unilateral bone-anchored hearing aids. Recently, some of the patients who benefited extremely well with unilateral aids applied for bilateral amplification. To date, 15 patients have been fitted with bilateral BAHAs. The benefits of bilateral amplification have been compared to unilateral amplification in 11 of these patients who have used their second BAHA for 12 months or longer. Following a subjective analysis in the form of comprehensive questionnaires, objective testing was undertaken to assess specific issues such as ‘speech recognition in quiet’, ‘speech recognition in noise’ and a modified ‘speech-in-simulated-party-noise’ (Plomp) test.‘Speech in quiet’ testing revealed a 100 per cent score with both unilateral and bilateral BAHAs. With ‘speech in noise’ all 11 patients scored marginally better with bilateral aids compared to best unilateral responses. The modified Plomp test demonstrated that bilateral BAHAs provided maximum flexibility when the origin of noise cannot be controlled as in day-to-day situations. In this small case series the results are positive and are comparable to the experience of the Nijmegen BAHA group.

Bone-anchored hearing aids (BAHAs) for people who are bilaterally deaf: a systematic review and economic evaluation

“…After selecting the highest level of evidence available for each comparison (BAHA vs BCHA, ACHA, unaided hearing or ear surgery, unilateral vs bilateral BAHA) and checking the remaining studies for BAHA models in current use, 12 studies (in 15 publications) were included in the systematic review of clinical effectiveness. 59,60,66,[76][77][78][79][80][81][82][83][84][85][86][87] The included studies were either one-group cohort pre and post studies or cross-sectional 'audiological comparison' studies (study design is discussed further in Quality assessment); no RCTs, controlled clinical trials or prospective cohort analytic studies were identified. Only two studies included BAHA models that are in current use.…”

“…Four studies 59,60,[85][86][87] comparing unilateral and bilateral BAHAs were included, and all were described as audiological comparison studies by reviewers (see Table 6, Appendix 10). None of these studies (or any eligible study from a lower level of evidence) compared unilateral and bilateral BAHAs using a model in current use.…”

“…The studies comparing unilateral with bilateral BAHAs included participants with various diagnoses, including recurrent otorrhoea, 60 chronic otitis, 60,86,87 congenital atresia, 60,87 otosclerosis, 86,87 congenital syndromes and hearing loss, 86 mastoid cavities 86 and microtia. 86 One study did not describe aetiology, simply stating that the majority of participants had symmetrical maximal or near-maximal conductive bilateral hearing loss.…”

“…86 One study did not describe aetiology, simply stating that the majority of participants had symmetrical maximal or near-maximal conductive bilateral hearing loss.…”

“…Mean PTA thresholds for AC were ~ 60 dB HL in these studies, and mean PTA thresholds for BC ranged from ~ 14 dB HL 59 to ~ 30 dB HL. 87 Some of the participants in the study by Bosman and colleagues 60 had previously used a unilateral BCHA and had been deprived of binaural cues since early life, 85 whereas participants in the study by Dutt and colleagues 86 were required to have previous experience of binaural hearing. Previous experience of binaural hearing was not explicitly stated by the other two studies.…”