My headphones are working some kind of strange.
The sound is very low even when set to maximum, and the speech is almost unhearable. When I listen to music I can't hear speech as well as when watching movies. Also there is some kind of strange noise.
But, when I try to unplug my headphones halfway everything works perfectly.
The problem is definitely not in headphones because I tested them on Windows.
I use Debian 8 with Cinnamon 2.6.13 on it.
UPD: The same situation on Linux Mint(on the same machine). Looks like this is some kind of drivers problems.