I'm running a MacBook Pro, OS X 10.12.5 with TeamViewer 12.0.78517
Recently i have noticed that whenever i start a connection to a remote PC, my local audio drops in volume significantly. I've turned off the remote sounds for the connections but it didn't make a difference. This is a problem because I often use skype and the reduction in volume makes it challenging to hold a conversation. This is not just in skype as it impacts music that I may be playing, etc. As soon as i kill the remote session, volume goes back up.