We're developing a product using ICS-40720 but we're having a problem with our prototype boards: there seems to be a quite strong noise at 2Hz in some microphones. What could be causing this?
I've captured background office noise and I attach 3 screenshots showing the frequency responses of different microphones capturing sound at the same time.
@nategil did you ever discover what was causing the low frequency noise?
I am experiencing a similar issue with the ICS-40618. We are seeing a 6Hz noise from the MIC output when measuring a quiet room.