Search found 91 matches

by tobiasherzke
Fri Mar 05, 2021 1:59 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

Yes the conversion to dB is done by MHASignal::pa22dbspl. See its documentation here: http://mha.hoertech.de/doc/master/namespaceMHASignal.html#adffb46b90b6e9460f06286bda1c6d1de mha_real_t MHASignal::pa22dbspl ( mha_real_t x, mha_real_t eps = 0.0f ) inline Conversion from squared Pascal scale to dB ...
by tobiasherzke
Wed Mar 03, 2021 5:11 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

Computation of level from signal in openMHA does not need to know the peaklevel that you configured in plugin transducers. To understand how the level computation from STFT spectra works in openMHA, you need to be aware of two openMHA properties: 1) Central calibration. Because hearing aid signal pr...
by tobiasherzke
Sat Feb 27, 2021 2:55 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

Checking Release Times (I use the words "decay" and "release" interchangeably in this thread.) Classic dynamic compressors in hearing aids often use a significantly longer release (or decay) time constant than attack time constant. The purpose of both time constants is to stabil...
by tobiasherzke
Sat Feb 27, 2021 1:17 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

A quick addition how we test the time constants in unit tests: We use a very similar setup to what I did in my previous post: set all filter time constants to 0 except for the one that I want to test, then simulate a step response. But instead of directly querying the filtered output levels, I allow...
by tobiasherzke
Sat Feb 27, 2021 1:11 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

Reproducing your attack time . Analyzing your graph: You have probably used an attack time constant of exactly 1 second to produce this graph (see analysis at bottom of this post). This is a very long attack time constant and not suitable for normal hearing aids, but openMHA is very flexible and ca...
by tobiasherzke
Fri Feb 26, 2021 7:30 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Re: Questions about time constants in dynamic compressor dc

The dynamic compressor dc can be configured with 3 different time constants for each frequency band. All three time constants are the time constants(*) of first-order low-pass filters that filter the input level of the frequency band for which they are specified: tau_rmslev - This time constant is o...
by tobiasherzke
Fri Feb 26, 2021 6:12 pm
Forum: User Applications
Topic: Questions about time constants in dynamic compressor dc
Replies: 8
Views: 2410

Questions about time constants in dynamic compressor dc

I have received this question by email and have gotten permission to post and answer it here: For the level tracking in the openmha dynamic compressor dc , were you following the classical definition of time constant, i.e., rise and fall time characterized in terms of reaching 63% of the level? I un...
by tobiasherzke
Fri Jan 15, 2021 8:55 am
Forum: Getting Started
Topic: Building openMHA on PC - winsock error
Replies: 8
Views: 3121

Re: Building openMHA on PC - winsock error

We in the openMHA core team do not use IDEs. Most use emacs for code editing, and for debugging we use the command line. Apart from CodeBlocks, I think also CLion, eclipse, QtCreator support the MinGW compiler. It may be difficult to configure them to actually do something useful with the openMHA so...
by tobiasherzke
Thu Jan 14, 2021 3:54 pm
Forum: Getting Started
Topic: Building openMHA on PC - winsock error
Replies: 8
Views: 3121

Re: Building openMHA on PC - winsock error

Please verify from an msys2 terminal that your libjack.a copy in MinGW is the same as the file in the Jack 1.9.11 installation and the same as displayed here: $ ls -l /mingw64/lib/libjack.a /c/Progra*/Jack/lib/libjack64.lib -rw-r--r-- 1 ... ... 41990 Mar 21 2016 '/c/Program Files (x86)/Jack/lib/libj...
by tobiasherzke
Wed Jan 13, 2021 3:25 pm
Forum: Getting Started
Topic: Building openMHA on PC - winsock error
Replies: 8
Views: 3121

Re: Building openMHA on PC - winsock error

cannot find -ljack You may have overlooked this point from the COMPILATION.md instructions: Copy libjack64.lib from the JACK installation (C:\Program Files (x86)\Jack\lib) to the lib sub-directory of your mingw64 directory and rename it to libjack.a afterwards. Windows may warn that the file may be...