Is there any way to prevent application from changing volume level of my microphone?

Question

I've recently switched from Windows to Ubuntu(15.10), it's my first experience with GNU/Linux and so far it was flawless except for one thing:
During facebook calls(it's based on Skype afaik, but it lacks the option to disable input autoadjust) firefox keeps adjusting my microphone volume to levels so high, that my fans can be heard. :/ I really have to use FB for that, as my girlfriend lives 400km away from me :/

Is there any way of preventing applications from changing volume?
Or maybe is it possible to use script that sets volume to exact position every 0.1s?

Sorry for my english, it's not my native.
Thanks in advance! :)

Answer 1

I had a similar problem. Sometimes it is impossible to prevent applications from trying to adjust the microphone level. With Ubuntu, it is at least possible to prevent ALSA from responding to such requests.

In the configuration file /usr/share/pulseaudio/alsa-mixer/paths/analog-input-internal-mic.conf (you might have to look for the correct file for your microphone), I changed to part

[Element Capture]
switch = mute
volume = merge
override-map.1 = all
override-map.2 = all-left,all-right

to

[Element Capture]
switch = mute
volume = 40
override-map.1 = all
override-map.2 = all-left,all-right

and after a sudo alsa force-reload, applications don't magically change the microphone volume anymore.

Does that solve your problem?