Screenshare Audio issues

Whenever I screenshare, audio appears to come out normal for those viewing for quite a bit, but eventually the audio turns into a buzzing noise. They say this noise gets worse as the stream goes on, and I have no idea what causes it. If I restart the stream, the buzzing disappears. This buzz seems to match with the audio, and doesn't appear to happen if there is no audio playing through the stream.
Please help out with this, I want to watch some stuff on my computer with my friends but this is putting a damper in things.