This voice record/playback device is based on ISD1820 chip, which can record/playback multiple-message. It can offer true single-chip voice recording, non-volatile storage, and playback capability for 8 to 20 seconds. For the sampling rate of 3.2KHz it can record for the total duration of 20 seconds.
If you want change the record duration, an external resistor is necessary to select the record duration and sampling frequency, which can range from 8 – 20 seconds (4-12kHz sampling frequency). This voice record module provides default connect to a 100k resistor through P2 by short cap. So the default record duration is 10s.