It clicks more than you think.
Examples - If I'm in an IRC chat, it clicks with every beep in that app. Same thing for an instant messages.
If I'm editing a video in Final Cut Pro, it clicks *every* time I start and stop playing something, which is literally every few seconds when editing. I usually just turn it off and edit using the analog line out instead when I'm editing video, but it's annoying that I have to do that.
It also clicks for every YouTube video I start or stop playing.
And, if I didn't route the system beeps to the analog line out, it would also click for all of those as well.
Ah, I see how we differ. My Bifrost is not connected to my computer, it's only connected to my Squeezebox.
OK, given your situation, I can see how that would get annoying.