Reported in tracker:
"The current rendering method of audio thumbnail waveforms - as far as I can tell - is logarithmic. This makes it hard for me to see low volume changes in audio.
Allowing to switch between logarithmic and linear audio thumbnail waveform rendering would make editing easier for my process, which is heavily based on where audio starts and stops.
In the case of ffmpeg, if the showwaves effect is used, the scale parameter can be set to use lin or log https://ffmpeg.org/ffmpeg-filters.html#showwaves"