I have personally never had any issues with audio on linux the past 5 years. ALSA and pulseaudio have become pretty mature now. Only thing i needed for hangouts to work was to install Chrome instead of Chromium and then it worked. Webcam, audio and mic worked out of the box. I have however heard that there are some issues with the iSight camera on Macs under Linux, I have not tried this myself though.
