Teamviewer 15.8.3 Sound

I see there were some sound issues resolved in 2017 with teamviewer 12.

I am on teamviewer 15.8.3

Sometimes I can get listen to the sounds on the host machine from the remote machine, and sometimes I can't.

When I can't, I will sometimes go to Extras->Options->Audio Conferencing on the host machine, and toggle between the different options under speakers. Sometimes it fixes it and sometimes it doesn't. Sometimes I also have to exit Teamviewer before returning to get it to work. And sometimes no matter what I do, I can't get the sounds.

On the remote machine, sometimes my partner is using headphones, and sometimes he is just listening to normal sound. Does he need to make any changes on his machine (my remote machine) so I can still hear his sounds on my host machine?

Thanks very much in advance!!!!