-I presume transmit power has been lowered significantly as coverage has improved, too; your cell always transmits at the lowest level it can get a reliable connection with to preserve battery life. This should reduce interference considerably.

Also, GSM phones used TDMA (keying the transmitter on and off to occupy one of -hm- eight, I believe - time slots on a given channel.)

This is practically asking for EMC issues.

LTE, on the other hand, transmits continously (I believe - I do not work in RF engineering anymore, but try to read up on new tech every now and then.:) - much less interference-causing than the constant on/off of TDMA.

I thought LTE worked on a timeslice schedule as well. I remember hearing that was one of the problems with carrier plans to start running LTE on unlicensed spectrum, because it doesn't play nice with listen-before-talk wifi.

I still hear speakers make noises when there is an incoming call, I assume it varies by country.