This directory contains a collection of reference configurations that implement signal processing algorithms based on literature. These configurations have been used in previous studies on hearing aid processing. For details see:
Baumgärtel, R. M., Krawczyk-Becker, M., Marquardt, D., Völker, C.,
Hu, H., Herzke, T., Coleman, G., Adiloğlu, K., Ernst, S. M., Gerkmann, T.,
Doclo, S., Kollmeier, B., Hohmann, V., & Dietz, M. (2015). Comparing
Binaural Pre-processing Strategies I: Instrumental Evaluation. Trends
in hearing, 19.
https://doi.org/10.1177/2331216515617916.
and
Hendrikse, M. M. E., Grimm, G., & Hohmann, V. (2020). Evaluation of the Influence of Head Movement on Hearing Aid Algorithm Performance Using Acoustic Simulations. Trends in Hearing, 24, 1–20. https://doi.org/10.1177/2331216520916682
The configurations listed below assume a binaural behind-the-ear (BTE) hearing aid microphone setup as depicted in HATS_BTE.png
Each hearing aid includes three microphones (front, middle and rear), the distances between the microphones are given in millimeters. The distance between the left and the corresponding right BTE-hearing aid microphones is 164 mm. Further details can be found in H. Kayser, S. D. Ewert, J. Anemüller, T. Rohdenburg, V. Hohmann, and B. Kollmeier (2019),“Database of Multichannel In-Ear and Behind-the-Ear Head-Related and Binaural Room Impulse Responses,” EURASIP Journal on Advances in Signal Processing, Volume 2009, 10 pages, Article ID 298605 https://sirius.physik.uni-oldenburg.de/hrir/298605.pdf
A Matlab/Octave function called mha_process_ref_algo.m is available to process an audio signal with a reference configuration. It is found in the mfiles directory.
The following algorithms are available:
Delay-and-subtract beamformer
Input channel used: front-left, front-right, rear-left, rear-right
Sampling rate: 48000 Hz
bilateral Adaptive differential microphone
Elko, G. W., & Pong, A. T. N. (1995, October). A simple adaptive first-order differential microphone. In Proceedings of 1995 Workshop on Applications of Signal Processing to Audio and Acoustics (pp. 169-172). IEEE.
Input channel used: front-left, front-right, rear-left, rear-right
Sampling rate: 44100 Hz
Binaural beamformer
Rohdenburg, T., Hohmann, V., & Kollmeier, B. (2007, October). Robustness analysis of binaural hearing aid beamformer algorithms by means of objective perceptual quality measures. In Applications of Signal Processing to Audio and Acoustics, 2007 IEEE Workshop on (pp. 315-318). IEEE.
Input channels used: front-left, front-right, middle-left, middle-right, rear-left, rear-right
Sampling rate: 16000 Hz
Adaptive MVDR beamformer
Baumgärtel, R. M., Krawczyk-Becker, M., Marquardt, D., Völker, C.,
Hu, H., Herzke, T., Coleman, G., Adiloğlu, K., Ernst, S. M., Gerkmann, T.,
Doclo, S., Kollmeier, B., Hohmann, V., & Dietz, M. (2015). Comparing
Binaural Pre-processing Strategies I: Instrumental Evaluation. Trends
in hearing, 19.
https://doi.org/10.1177/2331216515617916.
including bug fix done after communication with Daniel Marquardt, the developer of the algorithm, in the implementation in Hendrikse2020
Hendrikse, M. M. E., Grimm, G., & Hohmann, V. (2020). Evaluation of the Influence of Head Movement on Hearing Aid Algorithm Performance Using Acoustic Simulations. Trends in Hearing, 24, 1–20. https://doi.org/10.1177/2331216520916682
Input channel used: front-left, front-right, rear-left, rear-right
Sampling rate: 16000 Hz
Single-channel noise reduction
Breithaupt, C., Gerkmann, T., & Martin, R. (2008, March). A novel a priori SNR estimation approach based on selective cepstro-temporal smoothing. In Acoustics, Speech and Signal Processing, 2008. ICASSP 2008. IEEE International Conference on (pp. 4897-4900). IEEE.
Input channel used: front-left, front-right
Sampling rate: 16000 Hz
Binaural coherence filter
Grimm, G., Hohmann, V., & Kollmeier, B. (2009). Increase and subjective evaluation of feedback stability in hearing aids by a binaural coherence-based noise reduction scheme. IEEE Transactions on Audio, Speech, and Language Processing, 17(7), 1408-1419.
Input channel used: front-left, front-right
Sampling rate: 48000 Hz