If it's kind of close it just sounds like someone talking in a slightly lower or higher pitch. It can still be pretty intelligible with the frequency slightly o

If it's kind of close it just sounds like someone talking in a slightly lower or higher pitch. It can still be pretty intelligible with the frequency slightly off. Eventually it gets very distorted though and you start losing a big part of the waveform entirely. Try listening in to some websdrs and you'll see what it's like.