Comment 8 for bug 884652

I can confirm that the workaround in comment #7 works.
The fix is basically install 'pavucontrol', then start it and go to the "Input Devices" tab, unlock the channels (by clicking on the padlock on the right), and set "Front Right" to Silence.

Unfortunately when used with the google talk plugin the dynamic volume adjustment keeps bringing the "Front Right" up, but on apps that do not do that it works.