Abstract: Audio data is converted into a digital format at a selectable conversion rate and applied through a microprocessor into memory storage. Stored data is selectively recalled and reconverted into an analog format for reconstruction into human speech at a processing rate independent of the input storage rate. The write pointer address and the read pointer address during the storage and retrieval of data are maintained within a selected address differential in accordance with the input data rate and the processing rate. To repeat the retrieval of particular stored data from selected address locations, the data input storage is interrupted thereby holding in memory a selected portion of previously stored data. The amount of data retrieved during the repeat process is varied by controlling the write pointer and the differential address between the write pointer and the read pointer.