[Q] static noise in earpiece topic

has anyone else noticed a rhythmic static noise in the earpiece when making calls?
wondering if this is normal for the phone (it sounds like electrical interference), or if there's something going on specifically with mine.
it could be easy to miss unless you're listening for it - it blends in with the normal background static of the call.
but i hear it also when making VoIP calls when they're connecting, which should be dead silent.