Loud beeping sounds when in a call

[J.sibley]

Pretty much everytime i make or recieve a call at some point a loud beep can be heard (sounds like somebody is holding down a button on the keypad). Sometimes this will go on for up to 10 seconds, the person on the other end of the call can't hear this. 

Its been going on for over a year, using 2 different phones and happens with anybody that calls. 

Any help would be very much appreciated. 

Thanks. 

Jake 

[63johnw]

Call waiting ? @J.sibley  Someone trying to call you when you are on a call ?