I had this same problem. Win 10 laptop used to remote control win 7 desktop, and not long after ungrading to current version of Teamviewer, I could no longer hear sound from the remote computer. After switching both computers to use the Standard Playback Device and the Standard Recording Device in the Teamviewer Audio settings (both were previously set to use the "Default" devices) I could hear the sound from the remote computer again. Hopefully this helps or works for someone else.
... View more