Microphone self noise IMP34DT05

[frnt]

Hello,

I'm using the IMP34DT05 microphone and it records fine but there is always a noise overlapped and it is very annoying.

I have tried recording the background noise in anechoic chamber (see attached audio, high-pass filter alpha is 0.98). Do you know I to get rid of this noise? Is it related to microphone self-noise? Is there some processing library available from ST to remove such noise?

Could it be related to some issue with the pdm2pcm conversion? I’m using 24bits on 32 frame. The PDM2PCM filter gain is set to 30.

Best,

[frnt]

Here instead the high-pass filter alpha is 0.9 (see attached track). I'm also reporting the two frequency spectrum from audacity.

Here alpha 0.9.

Here alpha 0.98.Is this related to the microphone self-noise?

[eloibonte]

Hi frnt,

I am experiencing the same issue as you with my MEMS mic and the PDM2PCM library.

Have you found the solution for your problem ?

If so I would love to have it please.

Thank you,

Best,

Eloi

[pratik092002]

Hello,

Thank you for sharing the information regarding the IMP34DT05 microphone noise issue.

I am currently working with the same IMP34DT05 PDM microphone and facing a similar background noise problem during audio recording. I am using PDM to PCM conversion and experimenting with different filter parameters, but the noise is still present.

If possible, could you please share the firmware or example code used in your project for the microphone interface and PDM2PCM conversion? It would be very helpful for debugging and comparing configurations.

Also, if you found any specific configuration or processing method that helped reduce the noise, I would greatly appreciate your guidance.

Best regards
Pratik