A long time ago, I had used a software program called Sound Forge. In this program, you could set it up to have the program be minimized but yet still be able to activate the recording when ever you are ready to start. This was a great feature because you could then have another program, like windows media player opened, press play, and the Sound Forge recorder control panel would always be on top of all other windows that were opened. This would then allow you to quickly press the record button at any time without having to swap windows. Is this possible with Audacity?
If you use Audacity Beta and assuming your sound device is able to record computer playback, you can enable Sound Activated Recording in Audacity’s Transport menu, press Record, minimise Audacity, then when any sound playing in the computer is loud enough to trigger Sound Activated Recording, recording will start. When that sound stops playing, recording will pause. Obviously this means system beeps may be recorded too.
Audacity has no way to be always on top unless your operating system is able to pin windows on top. If it doesn’t you can usually find programs on the internet to pin windows on top, such as File Box Extender for Windows. Then you could restore Audacity to a small window size, pin it, then press the Record button to start a manual recording when you wish. Obviously clicking Record in Audacity switches focus to it, even if you can still see the other program.