I tried my test again. Same result. Everything works fine down through ListPlay. When I execute the Audio statement, I get a beep, but no sound, and all the previous results are erased. It ends up as if I just opened the notebook. This was working until two days ago. Maybe corrupted Mathematica code?

Most (all?) of the Audio* functions work on audio objects.

Using AudioData you can convert audio to data, and using Audio you can do the inverse.

Probably you want to access the data:

Import[filename,"Data"]

rather than an audio-object, which is new to version 11 (and the default import method).