Playing "8KHz audio" is not the same thing as a playing an "8KHz frequency" (which yes in this case is a actually a square wave, so technically its Fourier tran

Playing "8KHz audio" is not the same thing as a playing an "8KHz frequency" (which yes in this case is a actually a square wave, so technically its Fourier transform shows other frequencies being played - but the programmer only gets to set the frequency of the square wave).