a device for reading sound waveform data has a waveform rom for storing waveform data represented as an amplitude in a time series . sound waveform data is repeatedly read from the waveform rom . the reading of a single waveform corresponds to a single period . a scale rom stores a plurality of frequency dividing ratios . a programmable counter divides a signal having a predetermined frequency in correspondence with a frequency dividing ratio output by the scale rom and outputing a clock pulse . a counter counts the clock pulses and indicates the addresses of the waveform rom . the scale rom changes the frequency dividing ratio data during an arbitrary divided period of intervals in the period for reading the waveform data . during the period for reading the waveform by the counters , the sound waveform readout has a single frequency and accordingly a single period . the waveform reading period is devided into m number of intervals . a particular kth divided period interval between 0 and m is adjusted to a longer or shorter interval than the remaining m - 1 period intervals to allow fine adjustment of an average period improving overall period resolution capabilities .