Audacity for Tympan? Possible?


#1

Hello,
Can we try the Tympan card with Audacity whose method of auductive compression tests is the same for the “Audio Teency” card?


#2

I had forgotten that Audacity might have built-in effects that are similar to some of the algorithms in the current Tympan library. It’s cool that you pointed that out! I now see that Audacity has a “Compressor” under the “Effects” menu.

Looking at the Audacity “Compressor”, I see that it has settings for: attack time, release time, compression ratio, and threshold. So, yes, it does appear to have the functionality that we expect (http://openaudio.blogspot.com/search/label/Compression)

The Tympan library currently has two different implementations of an audio compressor:

  • There’s the simple compressor that I wrote as part of the blog post linked above. It is on our github here).
  • Then there’s a more complicated compressor that was originally developed by audiological researchers who we’re collaborating with at Boys Town National Research Hospital (BTNRH). It is called a Wide Dynamic Range Compressor (WDRC) and it is on our github here.

To my ears, the WDRC ends up sounding better than my simpler algorithm. I’m not quite sure why. The WDRC also incorporates a few more features than my simpler compressor. For example, the WDRC includes an extra compression regime for very loud sounds. For these loud sounds, greater compression can be applied so that it acts as a limiter rather than a compressor.

But, back to your original post…

What kind of comparison to the Audacity compressor are you interested in? What would you like to see? Note that my blog post does share the test signals used within the blog post. You could download those test signals and run them through Audacity!

Chip


#3

I see better the technical principle of your idea for the Tympan card. By the way I wanted to use “Audacity” to test the eardrum after every change of my parameters on the software. That would make my job more precise. But you used this measurement tool for the “AudioTeency” card whose CODEC is different (this is the sgtl5000 codec used for AudioTeency.).
I had heard about the DRC’s software technique. This is interesting because DRC also allows to increase the amplitude of the sound according to its frequency. I could design a software in “Assembler” of Microchip to create this device “DRC” (for Microchip and WDRC for you … :slight_smile: