Individual variability in speech recognition with compression and beamforming at positive signal-to-noise ratios

Abstract

Individuals with hearing loss often struggle to communicate in noisy conditions. Aggressive hearing aid (HA) processing, such as fast-acting wide dynamic range compression (WDRC), may reduce speech recognition under some circumstances, and there is concern about disproportionate reductions in listeners with poor working memory. We investigated how speech recognition is affected when WDRC is combined with highly directional beamforming intended to reduce noise from lateral and rear locations. We also sought to determine how listener factors—working memory, age, and hearing loss—affect such interactions in typical listening conditions, including positive signal-to-noise ratios (SNR) and different spatial noise locations. To-date 22 listeners with mild to moderately severe sensorineural hearing loss repeated low-context sentences (0°) mixed with six-talker interference at + 3 and + 8 dB SNRs, distributed equally in two ( + /−90°) or three ( + /−90°/180°) locations. Wearable HAs presented four signal processing combinations, matched for audibility: microphone directionality (omnidirectional or beamformer) and WDRC (fast- or slow-acting). Data show higher speech recognition with beamforming (re omnidirectional), especially at + 3 dB SNR, regardless of WDRC and spatial locations. Relative contributions of listener factors will be assessed in mixed models in the context of combined signal distortions from HA processing and interferers. [Work supported by NIH-K01DC018324.]