Contribution
Technical evaluation of hearing aid performance within a simulated everyday scene using the extended phase inversion technique
* Presenting author
Abstract:
An essential aim of hearing aids is to improve speech intelligibility in everyday life of hearing-impaired listeners through amplification and spatial or spectral noise reduction techniques. Technical evaluations in everyday life, however, are difficult due to the complexity and irreproducibility going alongside the diversity of everyday scenes. The goal of this study is to evaluate settings of commercially available hearing aids within such a simulated scene. Therefore, a virtual acoustic living-room scene was created in RAVEN using 7th order ambisonics, played back using a spherical 69-channel loudspeaker system for physically correct sound reproduction. Two pairs of commercial hearing aids, fitted to a KEMAR artificial head, were evaluated within the scene in omnidirectional, fixed beamforming and automatic adaptive beamforming settings. The extended phase inversion technique was applied to separate several acoustic objects and calculate output signal-to-noise ratios (SNRs) for different time intervals of the scene. The results showed substantial and significant increases in SNR for both the fixed and adaptive beamforming setting with both hearing aid types and for one hearing aid type also with omnidirectional setting. Overall, this combination of methods was found useful to analyze the technical behavior of hearing aids even when their exact signal processing is unknown.