@substring even after a proper menu>quit>shutdown or reboot I have the same behaviour and ES logs:
lvl0: VolumeControl::init() - Failed to find mixer elements!
lvl0: MUSIC Error - Unable to open SDLMixer audio: ALSA: Couldn't open audio device: Device or resource busy
lvl2: Mix_PlayMusic: Audio device hasn't been opened
lvl0: Error loading sound "../sounds/scroll.ogg"!
Audio device hasn't been opened
once I go to the menu>sound and change the device from auto>card or vice-versa (I hear a sound click), sound comes and back and ES logs shows:
lvl2: Shutting down SDL AUDIO
lvl0: VolumeControl::init() - Failed to find mixer elements!
lvl2: SDL AUDIO Initialized
lvl2: playing
also sound comes back after going into a game and chaning nothing in ES menu:
lvl2: Mix_PlayMusic: Audio device hasn't been opened
lvl2: Attempting to launch game...
lvl2: Shutting down SDL AUDIO
going back from game
lvl0: VolumeControl::init() - Failed to find mixer elements!
lvl2: SDL AUDIO Initialized
lvl2: playing
it seems that the following step is the key to have proper init of sound in ES
lvl2: Shutting down SDL AUDIO