Annoying system beep on space switch

When I switch spaces, I sometimes get an annoying ding (system noise). There is no error and everything works fine. I have a 5 second screencast showing the issue here: http://cloud.optimalweb.biz/1w3r1B1K0m09

Annoying, any suggestions?

Thanks!

I think it’s likely hotkey related. The system makes a sound if you use a hotkey that is not assigned. I wonder if that is what’s happening?

For instance, open Calendar.app and press ctrl-alt 1 (which isn’t normally doing anything in that app). Do you get the same sound?

If you use another method of changing space (eg cmd-tab, or swiping) do you ever hear the sound?