The open Master Hearing Aid Forum

Hi Julien. I'm with Bat&Cat. I just double checked with our people and the earpiece isn't open source. The audio interface hardware, the cape4all board, is though.

Nick Michael

Dan, This is a simple program that plays .wav files. You of course need to put some .wav files on the PHL in the correct place. Chose which file gets played by setting mha.wav.select. Setting mha.wav.select = mic will pass the mic signal through. Nick ------------------------------------------------...

Bertan, The 'adm' plugin is a standard directional algorithm used in the industry. No HRTFs involved. It's used with the 'decomb' plugin to equalize the low frequency rolloff that naturally happens with directional microphones. I'm adding this algorithm to the example program you've been using. I'll...

Satish, I ran checked this example and didn't see any phase difference between the channels. I checked this in an informal but thoroughly convincing way (to me at least). I made an input wav file that had the same signal in both channels then looked at the output wav file and saw that the channels s...

JacopoC, I've used an RPi 4 model B to compile a test plugin and other code for the PHL, but if you don't have one laying around you might want to wait a few weeks for a new Mahalia release before you buy one. There's been a lot of work on this lately for compiling directly on the PHL with progress ...

There's a problem running the BLE interface with the latest images (it has to do with node versions - no fun). It's possible to get this running though by updating some files on the PHL. There's a blog post about it with instructions at: https://bc-support.github.io/posts/BLE/ Let me know if you try...

Have you looked at the C++ code? It would be in your openMHA directory, openMHA/mha/plugins/fshift_hilbert/fshift_hilbert.cpp I'm not familiar with the algorithm myself. The documentation cites this reference for the fshift_hilbert: Scott Wardle. 'A hilbert-transformer frequency shifter' Proc. DAFX9...

I'm afraid I don't have much experience with this example. Have you looked at example 31, Adaptive Feedback Canceller? It might have a few more clues and it also explains more about the current state of the feedback canceller.

There are probably other people on here that could add more info.

There's a new blog post outlining a bare bones Ecological Momentary Assessment (EMA) system on the BatAndCat support site: https://bc-support.github.io/posts/EMA/ The example project demonstrates the basic techniques of saving data to files, setting the time on the PHL and playing sample .wav files....

Is this on the PHL?
I don't know much about node servers, but the Node Red service is set up on the PHL in
/etc/systemd/system/multi-user.target.wants/mahalia-nodered.service

Maybe there are some clues from that configuration?