Play radio; but only to fill in silences

March 15, 2012 5:28 AM

How to automatically mute (or pause) one audio source if any other audio source is playing.

I would like to play some background (radio or subsonic) music; but when I start a youtube video or vlc movie, I would like to give that audio priority and have the backgroud music temporarily muted or paused. Automatic. Because if it is not automatic I forget to unmute.

I'm interested in solutions for one machine; i.e. a software solution that would silence the radio program if subsonic is playing anything, but would silence the radio program ánd subsonic if any other audio source is started.
Another option might be to pipe the audio of the priority streams through the line-in of a background-music-computer which would somehow automatically give priority to line-in if there's an audio signal..
I would also be interested in AV receivers which would attenuate one source if another is playing or would automatically switch to one source if there's a signal on it. Is this a standard feature on contemporary receivers? How are other people solving this?

On preview, this seems to prevent a separate hardware solution

posted by Akeem to technology (6 answers total)

OS?
posted by pompomtom at 5:49 AM on March 15, 2012

With a little coding (probably AppleScript), Audio Hijack will do this on a Mac. Basically, you'd always be hijacking (ie listening to) your browser and VLC, and run a script to pause or mute your other source when the sound level rises above a certain threshold. It's a pretty commonly-desired thing; I'd be surprised if there weren't available user scripts to do it already.
posted by supercres at 6:07 AM on March 15, 2012

Windows 7 lets you adjust and/or mute volume by application (or window, I forget).
posted by dekathelon at 7:54 AM on March 15, 2012

OS = Win7.

dekathelon, can you automate those adjustments? I can disable any application manually, the problem is that I always forget to re-enable after a youtube video finishes and I only notice after 20 minutes that I have been music-less.
posted by Akeem at 8:37 AM on March 15, 2012

The effect you are describing is called ducking and involves a noise gate circuit.

Normally a noise gate mutes a channel when there's no signal on it above a specified level.

A ducking noise gate mutes (or pads) channel A when there is a signal above a specified level on channel B. Channel A 'ducks' out of the way of channel B. It's done all the time in broadcasting, for example, when background music ducks narration. Sounds like approximately what you want.

I can do it in Cakewalk and I can do it with hardware, but I don't have a clue how you'd do in your PC's soundcard software; but I'm sure there's a way.

So there you have some relevant search terms.
 
posted by Herodios at 9:38 AM on March 15, 2012

I don't think ducking is the answer.

If the video you wanted to prioritise is quiet, a compressor set up for ducking would then stop compressing quite quickly, and allow through the (unwanted) original signal.

I think dekathlon has it, but don't know enough about Win7 to expand.
posted by pompomtom at 5:19 AM on March 18, 2012