I had that model too and I used to jsut turn it right down so that I could barely hear the buzzing. I didn't want to hear DD every move, just when she was upset, and believe me, she knows how to make herself heard :-)
But she ended up getting a hold of the parent unit and wrecked it. So I bought the Target Baby Club Monitor and love it. It was cheap and it doesn't buzz. It actually only kicks in when a noise is heard (it's noise activated) IYKWIM. So the parent's unti is on standby and only if a noise louder than a certain threshold is heard, then the parent's unit turns itself on. You can also make that threshold higher (if there is a lot of ambient noise like heavy rainfall) or lower (if you want to hear a slight wimper.
Sasa