Long‐term evaluation of sound localisation in single‐sided deaf adults fitted with a BAHA device

Abstract

Objective To perform a long‐term evaluation of the localisation capabilities in the horizontal plane of single‐sided deaf patients fitted with a BAHA device. Design Single‐centre retrospective study. Participants Twenty‐one adults with single‐sided deafness (SSD) with normal hearing in the contralateral ear (pure tone average <20 dB, SDS > 90%) rehabilitated with a Cochlear BAHA device from 2003 to 2012 on the deaf side over a median follow‐up of 8 years. Outcome measures The task used in this paper is a sound localisation identification task with a set‐up of seven loudspeakers on a semi‐circular array at 30‐degree intervals performed at three periods: before BAHA, initially and at last follow‐up. Our main criterion of judgement was the root‐mean‐square (RMS) localisation error. In addition, the Bern Benefit in Single‐Sided Deafness Questionnaire (BBSS) was administered. Results The mean RMS localisation error was initially estimated at 64° without any rehabilitation (for a chance level RMS estimated at 81°). Initially, with the BAHA device, the RMS localisation error dropped to 51°. At the last follow‐up evaluation, a significant decrease at 23° was noted. Concerning the Bern Questionnaire, 19% of the patients (n = 4) did not report any change (score of 0), 33% (n = 7) are satisfied (score of +1 or +2) and 48% (n = 10) are very satisfied with the BAHA device (score better than +3). Conclusion Improvement of sound localisation in the horizontal plane for some SSD patients is likely related to altered processing of monaural spectral cues. The time needed to learn to use the azimuth‐dependent spectral cues takes time. Long‐term follow‐up should be considered for studies investigating sound localisation performance.

Horizontal sound localisation and speech perception in Bonebridge-implanted single-sided deafness patients

“…have demonstrated that localisation abilities in the horizontal planes are effectively enhanced in patients with single-sided deafness using BAHA devices during an average follow up of eight years. 14 Further, Bonne et al . suggested that the improvement may be related to the influence of device training and learning, the design of testing, the employment of distorted temporal cues and the reconstruction of the body map.…”

“…11 Another method used to improve hearing for patients with single-sided deafness is the bone-conduction hearing aid devices, which include bone-anchored hearing aids (BAHA; Cochlear ® ), the Baha ® Attract system (Cochlear ® ) and the Sophono ® , which make the amplified sound stimulate the contralateral normal-hearing cochlea via transcranial direct bone-conduction. [12][13][14][15][16] Data have shown that bone-conduction hearing aid devices can provide important amplification in hearing performance for single-sided deafness, improve patients' speech discrimination abilities in noisy environments and improve their QoL. While the bone-conduction hearing aid has led to certain benefits in hearing gain and patient satisfaction, it also results in some complications because of the percutaneous coupling that is required for fitting, including skin infection, soft tissue overgrowth of the abutment, failure to osseointegrate and loss of the titanium implant.…”

“…17 Conversely, another report states that localisation abilities can be improved and may be related to a change in monaural spectral cues processing. 14 Cochlear implantation is another option for patients with single-sided deafness. Studies have shown that cochlear implantation devices used in adults with single-sided deafness significantly decrease tinnitus and improve localisation, speech perception in noise and QoL.…”

“…17 Conversely, another report states that localisation abilities can be improved and may be related to a change in monaural spectral cues processing. 14…”

Increased maximum power output may improve speech recognition with bone conduction hearing devices

“…BCHD is an effective hearing solution for people with a conductive hearing loss (CHL) or mixed hearing loss (MHL), as they bypass any limitations on sound transmission associated with pathologies or anomalies of the outer or middle ear (den Besten et al 2019;Dimitriadis et al 2016;Iseri et al 2015). These devices can also help patients who suffer from single-sided deafness by transmitting sound received on the deaf side directly to the hearing cochlea (den Besten et al 2019;Bonne et al 2019;Flynn et al 2010). BCHD bypasses the conductive part of the hearing loss and, as such, inherently closes the air-bone gap (ABG).…”