User Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0 (Beta/Release) Build ID: 20130814063812 Steps to reproduce: 1. Open Firefox 2. Visit a site with audio and video, such as Youtube and reproduce a clip 3. While reproducing switch your audio output device Actual results: Audio continues to be reproduced by the first audio device. Expected results: Audio should be reproduced on the newly selected device, as happens in Google Chrome.

To be more specific. When Firefox is launched it will use Windows default audio output device but if you change it in control panel after Firefox have been started it will still use previous device thus not matching current default. All applications I know regard this change and start using new device immediately. I consider this a bug because let's say Firefox have been open for whole day and I've several tabs opened (eg. 30) and default device was speakers, but now it's night and I want to switch to headphones so I change it in control panel, but FF will still use speakers. Currently to make it in effect I've to restart FF which is quite annoying.