Shabaz,

Looks a good circuit. I designed a circuit using electrets many years ago now that was my introduction to these amazingly sensitive devices. I think it was some sort of volume sensor - if you shouted loud enough it activated something. I can't really remember as it was so long ago. The PCB design looks good.

Dubbie

Hi Christopher,

You're right, maybe they have been underused because local processing was difficult in the past. In theory a mic should (say) make a far higher quality window sensor, since it can hear broken glass but could also hear knocking on the window frame if burglars are trying to pull off the pane, and alert far earlier than the old metal tape on glass method : )

Also this part looked really interesting:

STMicroelectronics introduces IIS3DWB MEMS vibration sensor optimized for industrial monitoring

It is not strictly a mic, but picks up vibrations that could include some of the purposes you may be thinking of too. It looks really neat, it has on-chip filtering capabilities, and also streams to its own memory, so that the microcontroller can retrieve many samples all in one go to save energy and timing : ) Would be nice to try it out on different household scenarios!

Agreed.

I would be interested in an ultra sonic microphone to see if I could capture bat signals locally.

I would also like to see an infrasonic microphone to capture very low frequency sounds.

DAB

I get the impression microphones are an under-used component in people's microcontroller projects. Most people probably think of only using microphones to record human speech, but I'm sure there's an opportunity for audio outside of human hearing to filter on for a project.

Sounds very good in response. It is worth I try to use a couple of these instead the standard Adafruit boards I used for the ears of Seven of Nine