Approximate (facultative) name of icon:

1.	sound on
2.	sound off  / mute
3.	volume high
4.	volume low
5.	volume change
6.	sound options
7.	format 2.1
8.	format 2.0
9.	format 1
10.	format 5.1
11.	sound active
12.	sound inert / mute