HörTech Open Master Hearing Aid (openMHA)
Content of the openMHA release 4.7.0 (2018-11-12)
The software contains the source code of the openMHA Toolbox library, of the openMHA framework and command line application, and of a selection of algorithm plugins forming a basic hearing aid processing chain featuring
- bilateral adaptive differential microphones for noise suppression 
- binaural coherence filter for feedback reduction and dereverberation 
- multi-band dynamic range compressor for hearing loss compensation 
- spatial filtering algorithms:
- a delay-and-sum beamformer
- a MVDR beamformer 
- single-channel noise reduction 
- resampling and filter plugins
- STFT cyclic aliasing prevention
- adaptive feedback cancellation 
- probabilistic sound source localization 
Citation in publications
In publications using openMHA, please cite
Herzke, T., Kayser, H., Loshaj, F., Grimm, G., Hohmann, V., Open signal processing software platform for hearing aid research (openMHA). Proceedings of the Linux Audio Conference. Université Jean Monnet, Saint-Étienne, pp. 35-42, 2017.
As we are working on an updated paper, please check back this section of the README for updates.
For individual algorithms, please also refer to the list of publications at the end of this README.
For installation instructions, please see INSTALLATION.md
We provide with this release several examples of configuration files and sound examples. These are contained in the directory ./mha/examples
For instance, we can start an example featuring multiple algorithms together by changing the working directory to the directory that contains the example
read the configuration file, run processing of the audio file specified in the configuration in openMHA and quit openMHA afterwards with the following command:
mha ?read:prerelease_combination.cfg cmd=start cmd=quit
There are some known issues with Octave under macOS. The openMHA gui may not work correctly with octave. As an alternative Matlab can be used.
The qjackctl version provided by the JackOSX distribution is rather old. The user must replace the default Server Path setting with the absolute path to jackdmp (default: /usr/local/bin/jackdmp) (May not be necessary any more, check for yourself).
On some Apple machines jack needs to be run with root privileges to get real-time priority.
References for individual algorithms.
 Elko GW, Pong ATN. A Simple Adaptive First-order Differential Microphone. In: Proceedings of 1995 Workshop on Applications of Signal Processing to Audio and Accoustics; 1995. p. 169–172.
 Grimm G, Hohmann V, Kollmeier B. 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. 2009;17(7):1408–1419.
 Grimm G, Herzke T, Ewert S, Hohmann V. Implementation and Evaluation of an Experimental Hearing Aid Dynamic Range Compressor Gain Prescription. In: DAGA 2015; 2015. p. 996–999.
 Adiloğlu K, Kayser H, Baumgärtel RM, Rennebeck S, Dietz M, Hohmann V. A Binaural Steering Beamformer System for Enhancing a Moving Speech Source. Trends in Hearing. 2015;19:2331216515618903
 Gerkmann T, Hendriks RC. Unbiased MMSE-Based Noise Power Estimation With Low Complexity and Low Tracking Delay. IEEE Transactions on Audio, Speech, and Language Processing. 2012;20(4):1383–1393.
 Schepker H, Doclo S, A semidefinite programming approach to min-max estimation of the common part of acoustic feedback paths in hearing aids. IEEE Transactions on Audio, Speech, and Language Processing. 2016;24(2):366-377.
 Kayser H, Anemüller J, A discriminative learning approach to probabilistic acoustic source localization. In: International Workshop on Acoustic Echo and Noise Control (IWAENC 2014); 2014. p. 100–104.