The theoretical bit error-rate prediction technique proposed by Bello and Esposito has been adapted to an FSK communication system employing a receiver which samples at the centres of received digits. Laboratory tests using a noise simulator capable of producing pulses with controllable amplitude, occurrence time and phase distributions have allowed verification of the predictions to be obtained within the range of impulse rates for which the error rate due to the contamination of an information digit by more than one noise pulse is negligible.