Re: Annoying high-pitched sound
Hi Sarak,
I think that the sound is accoustic feedback. This happens when the microphone can hear the earphone, is amplified, makes more sound and is heard and amplified again and again. So the sound goes around and around. When it does work well, then the microphone cannot hear the earphone very much maybe because the earphone has a better fit into the ear canal (and therefore the sound cannot escape to the microphone), or then the gain is not too much.