a method , arrangement , and transceiver for monitoring noise on a twisted pair cable adapted to transfer digital subscriber line signals with a given data symbol rate . a spectrum analyzer measures the power spectral density of a background or substantially pure noise signal . a switch and frequency detector determine whether the background pure noise signal includes repetitive impulse noise , and if so , a processor calculates the pulse width of the repetitive impulse noise utilizing an established relationship between the given data symbol rate and the frequency of the repetitive impulse noise given by the power spectral density measurements .