Intercom Question

I have an intercom that allows me to listen/talk to anybody in front of my door. There is a switch that allows the speaker to act as a microphone. The speaker also emits a very anoying piercing sound whenever the doorbell button is pressed. Is there a component i can place in series or parallel to the speaker/mic to limit the sound without affecting the intercom capabilities? Unfortunately the the electronics to this unit is located in another part of my complex.. Any assistance appreciated.