It's a logo of a microphone. The microphone is the old style that radio announcers of the thirties might have used. There is a slash over the microphone that would indicate that a microphone is either not available or is not allowed for use.
Related to Mute Unmute Icon
Related icons are the icons with matching tags, as well as all music icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors