Sound localization with bilateral bone conduction devices

Abstract

Purpose To investigate sound localization in patients bilaterally fitted with bone conduction devices (BCDs). Additionally, clinically applicable methods to improve localization accuracy were explored. Methods Fifteen adults with bilaterally fitted percutaneous BCDs were included. At baseline, sound localization, (un)aided pure-tone thresholds, device use, speech, spatial and qualities of hearing scale (SSQ) and York hearing-related quality of life (YHRQL) questionnaire were measured. Settings to optimize sound localizing were added to the BCDs. At 1 month, sound localization was assessed again and localization was practiced with a series of sounds with visual feedback. At 3 months¸ localization performance, device use and questionnaire scores were determined again. Results At baseline, one patient with congenital hearing loss demonstrated near excellent localization performance and four other patients (three with congenital hearing loss) localized sounds (quite) accurately. Seven patients with acquired hearing loss were able to lateralize sounds, i.e. identify whether sounds were coming from the left or right side, but could not localize sounds accurately. Three patients (one with congenital hearing loss) could not even lateralize sounds correctly. SSQ scores were significantly higher at 3 months. Localization performance, device use and YHRQL scores were not significantly different between visits. Conclusion In this study, the majority of experienced bilateral BCD users could lateralize sounds and one third was able to localize sounds (quite) accurately. The localization performance was robust and stable over time. Although SSQ scores were increased at the last visit, optimizing device settings and a short practice session did not improve sound localization.

Evaluating the effectiveness of bone conduction hearing implants in rehabilitation of hearing loss

“…Chin et al (2021) also demonstrated better hearing threshold, speech reception thresholds in noise and directional hearing with bilateral simultaneous implantation with the tBCHD Bonebridge devices [25]. Similarly, Caspers et al (2022) studied the efficacy of bilateral implantation with pBCHDs on sound localization [26]. Heath et al (2021) published a systematic review to assess the outcomes of bilaterally fitted patients.…”

Evaluation of the Benefits of Bilateral Fitting in Bone-Anchored Hearing System Users: Spatial Resolution and Memory for Speech

“…Dun and coauthors reported a score of 5.8 in the spatial scale of the SSQ49 for bilaterally fitted children. Caspers et al (2022 ) also collected SSQ scores on bilaterally implanted BAHS users (adults) but the data were not reported. Other studies ( Kunst et al 2008 ; Bosman et al 2018 ; Cuda et al 2021 ; Bosman et al 2021 ) collected SSQ49 scores using a group of adult users—most of which were unilaterally implanted.…”

Sound Localization and Lateralization by Bilateral Bone Conduction Devices, Middle Ear Implants, and Cartilage Conduction Hearing Aids

“…Johnson et al (2017) [41] described that the difference between premiumfeature hearing aids (i.e., with multi-channel adaptive DMs, pinna effect simulation, and an advanced synchronization function) and basic-feature hearing aids (i.e., with singlechannel adaptive DMs and a basic synchronization function) was not significant in selfreported everyday sound localization. Caspers et al (2021) [29] switched off adaptive DM and noise reduction in the setting of BCDs to avoid deterioration in localization performance.…”

“…They stated that the difference must be caused by late-development brain plasticity for binaural hearing. Caspers et al (2021) [29] reported that bilaterally fitted patients with bilaterally acquired hearing loss, as well as patients with congenital hearing loss, were capable of localizing sounds (quite) accurately. For the obtained bilateral BC thresholds, they described that sound lateralization was more accurate in patients with symmetric and near-normal BC thresholds when compared with patients with either asymmetric BC thresholds or patients with BC thresholds of 25 dB and higher, and that normal symmetric thresholds did not warrant good localization.…”

“…Caspers et al (2021) [29] investigated sound localization in 15 patients bilaterally fitted with BCDs (Baha4 or Baha5) and explored clinical methods to improve localization accuracy. Sound localization was measured at baseline, and settings to optimize sound localization were added to the BCDs.…”