Hi all (first post please be gentle :), At the moment I am trying to write a simple gtk application which in essence can detect this scenario : 'master' volume is muted. And at the same time a client application is attempting to play audio. I have been digging through the API and I can't find anything obvious about the master volume. I am using the Glib asynchronous api. So far I can query the server about the number channels and their respective volumes but I cannot query the overall master volume. I thought it would be a case of setting up a callback whereby any channel attempting to play a stream would notify a custom call back which would then check if all channels are muted and then notify the GUI accordingly. another idea was to use PA_STREAM_START_MUTED. Connect to all streams and on a playback event check if any has this stream state ? clutching at straws to be honest. long time since I toyed with C API's. any help would be much appreciated. Conor