This tool shows available information about render and capture audio usages. It uses ActivityReporter, Usage(Reporter|Watcher), UsageGain(Reporter|Listener), as well as usage VolumeControls available from the AudioCore interface.
Current per-usage data is updated in real-time, for all render/capture usages:
To switch between Activity | State | Volume | Gain display modes, press arrow keys (up | left | down | right for Activity | State | Volume | Gain respectively), or numerical keys 1-4 (handy when arrow keys are unavailable).
In Activity mode, for every usage a six-letter abbreviation is displayed iff it is active: Backgd, Media, Interr, Foregd, SysAgt, Comms.
In State, Volume and Gain modes, the first letter of each usage is shown alongside that usage's information.
To quit the audio_listener tool, press Q or [Enter].