The bit rate determines the quality of the sound recorded. The higher the bit rate is, the better the sound quality will be. However, a higher bit rate will make the MP3 files larger.
Hi-Q MP3 Voice Recorder by default use 128 kbps. This results in 1 MB file size per minute of recording. This default bit rate is suitable for most recordings including general musical clips and concerts. However, if you want to record your own musical performance, it is best to use 224 or 256 kbps bit rate to ensure minimal loss of quality.
If you record lectures, sermons, or talks (with no music), you can set it to 64 kbps (0.5 MB/minute) and you will get a good enough sound quality.