A Fractional Captain complained that his Company allows the aircraft's inflight phone to receive calls during approach which interrupts communications. Unfortunately a means of silencing the phones is unavailable.

Narrative

I have had two recent instances when the flight phone ringing caused a disruption of communications with ATC. On my last tour; we were on arrival into a high traffic environment and talking to SOCAL approach when the flight phone began ringing. This ringing was so loud that we missed several communications from ATC. Our flight phone was MEL'ed; so we could not answer the phone. In addition; we could not have answered the phone without degrading our necessary flight duties during this busy phase of flight. Fortunately; no critical situations resulted. Yesterday; during takeoff roll; the phone began to ring. Again; we had great difficulty hearing ATC instructions with this loud noise in the cockpit. Due to the busy phase of flight (takeoff and departure) we could not have answered the phone; anyway. This is a serious safety issue that unnecessarily impacts safety of flight. Two things should be done to eliminate this safety issue. First; the Company should establish a policy to only attempt contact with flight crews by flight phone during the cruise phase of flight. This is often the only time when crew members will have the time to answer the phone without degrading safety of flight. Second; There should be a way of silencing the phone ringing in the cockpit. Particularly with a partially inop phone; there is no way to eliminate this distracting noise from the cockpit. Perhaps a master power switch that would allow shutting off the phone from the cockpit would help.