Abstract: A dial signal receiver for receiving and decoding telephone digit signals in either dual-tone multifrequency (DTMF) or rotary dial pulse form is disclosed. DTMF digits are accepted, if, simultaneously, both the high and low frequency components, derived from a band-split filter, repetitively pass a short term check; and each component passes a long term check once. The short term checks comprise repetitively measuring the period of two consecutive cycles of each component of the input signal. The long term check comprises measuring the period of a number of cycles of each component of the input signal. The number of cycles for each component is dependent on the nominal frequency determined by the short term check of that component. At the end of a cycle related period, a "window" is opened for a time interval related to the expected frequency, as determined by the short term check. If a short term check pulse occurs during the open window period, the related component is accpeted as valid.