Is there a way to disable or mute a dial tone?

Question

A co-worker insists on placing all calls by dialing straight on the phone without picking up the reciever. The dial tone comes out throught the speaker very loud and makes me feel like stabbing something. (Just kidding of course)

Is there a way to disable or mute the dial tone while still keeping the full functionality?

If it helps, the phone model is Panasonic KX-T7420.

Answer 1

They could turn the speakphone volume down even to mute, which is easy. However, then they can't hear when the call is answered, which defeats the point of using the speaker. So you could have a fight on your hands.

Ask them politely to at least turn it down. They probably don't realise isn't getting on your nerves.

Alternatively, shove the handset up their *&$%!

Answer 2

Tell them to use a headset. Besides, that's what they're there for, especially if you don't have an office.