I connect ADMP441(digital MEMS microphone) to ADAU1701. The sound volume is not high enough.
So I add 2 linear gain in serial to boost the volume. The first gain is 15, the second is 6. Then I get a high volume sound which I can hear it easily. But I can hear obvious envirnment noise as well. Is that normal? If no, how does it come? how to eliminate it?