Good stuff Matt.
I was reading one of the Soviet pilot interviews online (can't remember which one) not long ago and the subject of the poor performance of their radios came up. This pilot said that he had 'liberated' a german helmet and plugged it into his radio, and was totally surprised when he heard his commanders voice loud and clear.
Seems like at least part of the problems they experienced with R/T came from the earphones.
Claidemore