Buzzer that's corelated with the engines RPM?

So I hear some kind of buzzer, which comes from the passenger's side of the dashboard. It's directly related to the engine RPM.

So is this some kind of buzzer so I can hear how much RPM my engine is running, or is there something wrong? It sounds like a very tiny turbine in a high-pitched tone.

I'll see if I can make a video tomorrow.