I have noticed on different airplanes (metro III / 23 type) that I very often hear a painfully loud cracklin/popping noise when the PTT button of the other pilot gets released. When I key the mike and release it myself, you hear the normal "clicking" noise. When the other pilot keys the button it is much louder, and when he releases it, it sounds like a small explosion.
I use a Bose A20 headset, the other guy was using a David Clark with ANC. The same thing has happened when the other guy is using a Bose A20 as well. So I don't think it depends on the type of heaset being used. The other pilot didn't seem to hear anything out of the ordinary, but it really bugs/hurts me. I've always had sensitive ears, but never had an issue soo far.
I can turn the volume down, but if I turn the volume down to non-painful levels, I can't hear the radio anymore...
Some google-fu showed me this link: https://electronics.stackexchange.com/q ... c-is-keyed
It is form a non aviation radio, but it sounds very similar to my problem. Not sure how the solution would fit in an airplane though.
Any hints would be greatly appreciated!