Recording Time per 128MB depends on the sampling rate, a higher recording sampling frequency brings better recording quality, but takes more memory space. Below is the recording time with different sampling rate:

- 8000 Hz — 8 hours  
- 11025 Hz — 5.8 hours  
- 16000 Hz — 4 hours  
- 22050 Hz — 2.9 hours  
- 32000 Hz — 2 hours

If the memory capacity is bigger, the recording time will be longer, for example, 256MB has maximum 16 hours recording time.