I want to unmute line-in/microphone sound on a laptop. On my desktop PC, it's disabled by default, so you don't hear sound coming from it at all times, but it can be unmuted via
Control Panel > Sound > Speaker properties > Levels. This allows me to hear the output from whatever device is connected, be it a microphone, nintendo DS, FM radio etc.
The problem is, that on all 3 of my laptops, the Levels tab has no option to mute anything other than the speakers themselves, so I can't hear anything without first recording it. What's going on?