[pulseaudio-discuss] Support for buttons on USB headsets?

[Pierre-Louis Bossart]

My USB headsets have mute, volume up and volume down buttons exposed 
with an HID interface. When I use them with Ubuntu/PulseAudio nothing 
happens.
Wondering if this is not supported at all, if my config is broken or if 
a manual setup is required as described in [1] - a basic workaround to 
link keycodes and alsamixer. If PulseAudio had this information it could 
do a much better job.
Thoughts?
Thanks,
-Pierre

[1] https://help.ubuntu.com/community/PlantronicsUSBHeadsetControls