I have looked this up in the past, and I agree that phones should be silenced by both parties of a professional visit, however it is prudent and perfectly legal in many states to surreptitiously tape a doctor visit…there is much feedback and instruction that cannot always e retained during the visit… and with voice recording, you can replay the visit over and review…in addition it would be to everyone’s benefit to just keep quiet and nobody gets offended or feels on edge.