Objective: Binaural beamformers are super-directional hearing aids created by combining microphone outputs from each side of the head. While they offer substantial improvements in SNR over conventional directional hearing aids, the benefits (and possible limitations) of these devices in realistic, complex listening situations have not yet been fully explored. In this study we evaluated the performance of two experimental binaural beamformers. Design: Testing was carried out using a horizontal loudspeaker array. Background noise was created using recorded conversations. Performance measures included speech intelligibility, localization in noise, acceptable noise level, subjective ratings, and a novel dynamic speech intelligibility measure. Study sample: Participants were 27 listeners with bilateral hearing loss, fitted with BTE prototypes that could be switched between conventional directional or binaural beamformer microphone modes. Results: Relative to the conventional directional microphones, both binaural beamformer modes were generally superior for tasks involving fixed frontal targets, but not always for situations involving dynamic target locations. Conclusions: Binaural beamformers show promise for enhancing listening in complex situations when the location of the source of interest is predictable.

The occlusion effect is commonly described as an unnatural and mostly annoying quality of the voice of a person wearing hearing aids or hearing protectors. As a result, it is often reported by hearing aid users as a deterrent to wearing hearing aids. This paper presents an investigation into active occlusion cancellation. Measured transducer responses combined with models of an active feedback scheme are first examined in order to predict the effectiveness of occlusion reduction. The simulations predict $18\mathrm{dB}$ of occlusion reduction in completely blocked ear canals. Simulations incorporating a $1\mathrm{mm}$ vent (providing passive occlusion reduction) predict a combined active and passive occlusion reduction of $20\mathrm{dB}$ . A prototype occlusion canceling system was constructed. Averaged across 12 listeners with normal hearing, it provided $15\mathrm{dB}$ of occlusion reduction. Ten of the subjects reported a more natural own voice quality and an appreciable increase in comfort with the cancellation active, and 11 out of the 12 preferred the active system over the passive system.

Objective: To introduce and verify an algorithm designed to administer adaptive speech-in- noise testing to a specified reliability at selectable points on the psychometric function. Design: Speech-in-noise performances were measured using BKB sentences presented in diffuse babble-noise, using morphemic scoring. Target of the algorithm was a test-retest standard deviation of 1.13 dB within the presentation of 32 sentences. Normal-hearing participants completed repeated measures using manual administration targeting 50% correct, and the automated procedure targeting 25%, 50%, and 75% correct. Aided hearing-impaired participants completed testing with the automated procedure targeting 25%, 50%, and 75% correct, repeating measurements at the 50% point three times. Study sample: Twelve normal-hearing and 63 hearing-impaired people who had English as first language. Results: Relative to the manual procedure, the algorithm produced the same speech reception threshold in noise (p = 0.96) and lower test-retest reliability on normal-hearing listeners. Both groups obtained significantly different results at the three target points (p < 0.04) with observed reliability close to expected. Target accuracy was not reached within 32 sentences for 18% of measurements on hearing-impaired participants. Conclusions: The reliability of the algorithm was verified. A second test is recommended if the target variability is not reached during the first measurement.

Background:Large variations in perceptual directional microphone benefit, which far exceed the variation expected from physical performance measures of directional microphones, have been reported in the literature. The cause for the individual variation has not been systematically investigated.Purpose:To determine the factors that are responsible for the individual variation in reported perceptual directional benefit.Research Design:A correlational study. Physical performance measures of the directional microphones obtained after they had been fitted to individuals, cognitive abilities of individuals, and measurement errors were related to perceptual directional benefit scores.Study Sample:Fifty-nine hearing-impaired adults with varied degrees of hearing loss participated in the study.Data Collection and Analysis:All participants were bilaterally fitted with a Motion behind-the-ear device (500 M, 501 SX, or 501 P) from Siemens according to the National Acoustic Laboratories' non-linear prescription, version two (NAL-NL2). Using the Bamford-Kowal-Bench (BKB) sentences, the perceptual directional benefit was obtained as the difference in speech reception threshold measured in babble noise (SRTn) with the devices in directional (fixed hypercardioid) and in omnidirectional mode. The SRTn measurements were repeated three times with each microphone mode. Physical performance measures of the directional microphone included the angle of the microphone ports to loudspeaker axis, the frequency range dominated by amplified sound, the in situ signal-to-noise ratio (SNR), and the in situ three-dimensional, articulation-index weighted directivity index (3D AI-DI). The cognitive tests included auditory selective attention, speed of processing, and working memory. Intraparticipant variation on the repeated SRTn's and the interparticipant variation on the average SRTn were used to determine the effect of measurement error. A multiple regression analysis was used to determine the effect of other factors.Results:Measurement errors explained 52% of the variation in perceptual directional microphone benefit (95% confidence interval [CI]: 34‐78%), while another 37% of variation was explained primarily by the physical performance of the directional microphones after they were fitted to individuals. The most contributing factor was the in situ 3D AI-DI measured across the low frequencies.Conclusions:Repeated SRTn measurements are needed to obtain a reliable indication of the perceptual directional benefit in an individual. Further, to obtain optimum benefit from directional microphones, the effectiveness of the microphones should be maximized across the low frequencies.

Objectives: This study assessed hearing aid benefits for people with a normal audiogram but hearing-in-noise problems in everyday listening situations. Design: Exploratory double-blinded case-control study whereby participants completed retrospective questionnaires, ecological momentary assessments, speech-in-noise testing, and mental effort testing with and without hearing aids. Twenty-seven adults reporting speech-in-noise problems but normal air conduction pure-tone audiometry took part in the study. They were randomly separated into an experimental group that trialed mild-gain hearing aids with advanced directional processing and a control group fitted with hearing aids with no gain or directionality. Results: Self-reports showed mild-gain hearing aids reduce hearing-in-noise difficulties and provide a better hearing experience (i.e., improved understanding, participation, and mood). Despite the self-reported benefits, the laboratory tests did not reveal a benefit from the mild-gain hearing aids, with no group differences on speech-in-noise tests or mental effort measures. Further, participants found the elevated cost of hearing aids to be a barrier for their adoption. Conclusions: Hearing aids benefit the listening experience in some listening situations for people with normal audiogram who report hearing difficulties in noise. Decreasing the price of hearing aids may lead to greater accessibility to those seeking remediation for their communication needs.

To investigate the extent to which Headphone Accommodations in Apple AirPods Pro attend to the hearing needs of individuals with normal audiograms who experience hearing difficulties in noisy envir...