I am running Ubuntu 14.04.2. This is a new installation, but I was able to play audio through speakers or headphones yesterday by selecting the desired output in the Sound|Output dialog. Today, I only get headphones.
The curious thing is that, in the Sound|Output dialog, there is an Output volume slider bar. When I click on the slider tab, there is a "popping" sound that plays through my speakers! This is not an audio artifact, I believe it to be an audio waveform that plays a pop. I can select my headphones, click on the slider tab, and hear this same waveform through my headphones.
I have looked all over the web and tried a number of the suggested solutions, but so for none of them have worked.
The Sound|Output dialog lists 7 possible outputs:
- HDMI/DisplayPort Barts HDMI Audio [Radion HD6800 Series]
- Digital Output (S/PDIF) Built-in Audio
- Analog Output Built-in Audio
- Digital Output (S/PDIF) SoundBlaster Live! 24-bit External SB0490
- Analog Output SoundBlaster Live! 24-bit External SB0490
- Digital Output (S/PDIF) Wireless Audio
- Analog Output Wireless Audio
4 through 7 worked yesterday. Today, only 6 and 7 can play the Sound|Output dialog's Test Sound, but I can still get a clear popping sound on all of 4 through 7.