I'm recording breathing sounds (inside anechoic chamber) with a MEMS microphone in a custom housing. The sound level is low; and near the noise floor of the mic, so we have a lot of input gain and the result is quite noisy. How can the noise be reduced?
Here is what I'm working on:
- Removed all ground loops
Reducing the microphone noise floor with electronics. (Battery power, bypass capacitors)
Low pass filtering at the microphone's output.
Using a quiet mic. preamp (RDL RU-MLA2)
Impedance matching with series and shunt loads
Noise gating is a nice idea but I understand this gates the quiet bits, where there is no signal anyway. If you suggest this please explain in detail how you think it could reduce the SNR of my signal.