[alsa-devel] snd_pcm_hw_params resets microphone boost

I have small program that captures audio from a microphone. As my microphone is very sensitive, I prefer to mute the microphone boost before capturing. I open alsamixer and set volume of the microphone boost to zero, save settings and exit. Then I execute my program. I see that it resets volume of the microphone boost in snd_pcm_hw_params. What should I do resolve this problem? Where can I find default value and change it?