Occasionally I'll run an application or something from the web, usually something with both Audio and Video, and after playing it I no longer have audio on my Mac. I've heard others grumbling about this too.

What happens is that the 'offending' application is setting your Audio Output frequency to a higher frequency that other apps can playback with. In my case my frequency gets set to 96,000.0 Hz on occasion.

To reset your Audio settings so that you hear system and other audio events again you just need to open the app: Audio Mini Setup, make sure you're on the Audio Devices tab, and in the bottom right corner, set the Audio Output Format to 44100.0 Hz.

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