lost audio on Linux Mint

[ephemera]

Hello,

I'm a long-time user of Avidemux (current ver 2.8.1 & running on Linux Mint Cinnamon) for editing my videos. While I use it a lot, I'm far from a power user, for the most part using default settings except I change the saving format to MP4.

Yesterday everything was fine. Today, it won't play audio, even tho the videos I've brought in to edit are all fine. I can "see" the audio bouncing around in the bottom right corner graph, and my Audio Tracks Config setting says track 1 is enabled.

Any ideas on how to fix the issue? Googling hasn't been helpful.

[szlldm]

Check Preferences/Audio/AudioDevice. It should be PulseAudio.
Also check system settings (Sound/Applications).

[ephemera]

Brilliant!

But how did it get changed? "Local playback downmixing" was set on 'stereo headphones', and "audio device" was set on 'dummy'! No wonder I couldn't hear anything!