You may have enabled the option to mute UI sounds during playback. Try to turn it off and see.
Play GUI sounds is set to "Only when playback stopped". When I set it to always, it broke the audio in ES and RA. Weird. I tried it again, audio remained working in ES and RA, both. I think I will say this is just some sort of gremlin. It has been working fine today. I haven't made any changes compared to yesterday. As long as it works, I'm happy.