An Evaluation of Hearing Aid Beamforming Microphone Arrays in a Noisy Laboratory Setting

Abstract

People with hearing loss experience difficulty understanding speech in noisy environments. Beamforming microphone arrays in hearing aids can improve the signal-to-noise ratio (SNR) and thus also speech recognition and subjective ratings. Unilateral beamformer arrays, also known as directional microphones, accomplish this improvement using two microphones in one hearing aid. Bilateral beamformer arrays, which combine information across four microphones in a bilateral fitting, further improve the SNR. Early bilateral beamformers were static with fixed attenuation patterns. Recently adaptive, bilateral beamformers have been introduced in commercial hearing aids.The purpose of this article was to evaluate the potential benefits of adaptive unilateral and bilateral beamformers for improving sentence recognition and subjective ratings in a laboratory setting. A secondary purpose was to identify potential participant factors that explain some of the variability in beamformer benefit.Participants were fitted with study hearing aids equipped with commercially available adaptive unilateral and bilateral beamformers. Participants completed sentence recognition testing in background noise using three hearing aid settings (omnidirectional, unilateral beamformer, bilateral beamformer) and two noise source configurations (surround, side). After each condition, participants made subjective ratings of their perceived work, desire to control the situation, willingness to give up, and tiredness.Eighteen adults (50–80 yr, M = 66.2, σ = 8.6) with symmetrical mild sloping to severe hearing loss participated.Sentence recognition scores and subjective ratings were analyzed separately using generalized linear models with two within-subject factors (hearing aid microphone and noise configuration). Two benefit scores were calculated: (1) unilateral beamformer benefit (relative to performance with omnidirectional) and (2) additional bilateral beamformer benefit (relative to performance with unilateral beamformer). Hierarchical multiple linear regression was used to determine if beamformer benefit was associated with participant factors (age, degree of hearing loss, unaided speech in noise ability, spatial release from masking, and performance in omnidirectional).Sentence recognition and subjective ratings of work, control, and tiredness were better with both types of beamformers relative to the omnidirectional conditions. In addition, the bilateral beamformer offered small additional improvements relative to the unilateral beamformer in terms of sentence recognition and subjective ratings of tiredness. Speech recognition performance and subjective ratings were generally independent of noise configuration. Performance in the omnidirectional setting and pure-tone average were independently related to unilateral beamformer benefits. Those with the lowest performance or the largest degree of hearing loss benefited the most. No factors were significantly related to additional bilateral beamformer benefit.Adaptive bilateral beamformers offer additional advantages over adaptive unilateral beamformers in hearing aids. The small additional advantages with the adaptive beamformer are comparable to those reported in the literature with static beamformers. Although the additional benefits are small, they positively affected subjective ratings of tiredness. These data suggest that adaptive bilateral beamformers have the potential to improve listening in difficult situations for hearing aid users. In addition, patients who struggle the most without beamforming microphones may also benefit the most from the technology.

Efficacy and Effectiveness of Advanced Hearing Aid Directional and Noise Reduction Technologies for Older Adults With Mild to Moderate Hearing Loss

“…Although in the current study the effects of DM and NR features were not examined separately, it is likely that the benefit observed in the HINT was mainly from DM technologies. The robust findings across all five listening conditions agree with previous literature regarding the efficacy of multi-channel adaptive DMs (Blamey et al 2006), bilateral beamformers (Picou & Ricketts 2018), and speech-seeking DMs (Wu et al 2013b).…”

“…Researchers also have tried to determine if premium DM and NR technologies deliver more benefit than basic technologies. Laboratory research has consistently shown that bilateral beamformers (Picou & Ricketts 2018) and speech-seeking DMs (Wu et al 2013a;Wu et al 2013b) outperform basic-level DMs. Pinna-simulation directivity can improve front-to-back localization (Keidser et al 2009).…”

Emerging Technologies, Market Segments, and MarkeTrak 10 Insights in Hearing Health Technology

“…5 In 2004, the introduction of wireless technology led to the development of innovative features such as streaming sound between hearing aids and consumer electronics products, connectivity between hearing aids and smartphones that enabled apps to give greater hearing aid control to the user, and data sharing between left-and right-worn hearing aids that enabled beamforming and other sophisticated signal processing benefits for hearing aid wearers. 6,7 In recent years, innovation has expanded beyond technology into services, business models, and product categories for new market segments.…”

Benefits of Beamforming With Local Spatial-Cue Preservation for Speech Localization and Segregation

“…Generally, beamformer systems designed for hearing-aid applications try to reach a balance between SNR improvement and spatial-cue preservation (Van den Bogaert, Doclo, Wouters, & Moonen, 2008, 2009) and thus may not provide speech-in-noise benefits as large as those that are theoretically possible. Indeed, recent studies that evaluated beamforming hearing aids under relatively complex listening situations found rather modest improvements in speech intelligibility relative to standard directional microphones (e.g., Picou, Aspell, & Ricketts, 2014;Best, Mejia, Freeston, van Hoesel, & Dillon, 2015;Picou & Ricketts, 2019;V€ olker, Warzybok, & Ernst, 2015;Wu et al, 2019).…”