I do have similar problems on Xperia 10 II , the audio on calls hopefully not very often (happened 3 - 4 times) in ~6 months I use it. When I am in a call and I have the sound on phone’s headphone (not Speaker / external headphones / bluetooth). Suddenly I heard a sound like short-circuit the speaker and I couldn’t hear any more. As I figured out:
- The person I have the call can hear me.
- I can select Speaker and I can hear again the call.
- Also with headphones (audiojack) works again.
- I couldn’t hear even music / sound from videos when this happened.
- After reboot sound and calls were working fine
- Restarting home screen from Settings->Utilities brought the sound back too.
With videos also, on Gallery’s Video player, when I play videos in several formats, some times video doesn’t start play and the app crashes. Surprisingly when I restart the app and go play that video it plays like nothing happened. This is happening some times after 2 - 3 videos played up to 30 - 40, or could not happen at all.