Sound Level Warning Device: Suggested shopping list

lyndon:
You said you want it to be accurate. How are you going to calibrate it?

To be more specific, I want it to be fairly accurate. Not laboratory-level by any means. I read a post where the person used a dB meter app on their phone to get a baseline and adjusted it from there. Hopefully that will work for me.

DanV:
Googling “diy sound level meter” produces 13,500,000 results.

Just pay little attention to the instructables articles. They can often be of little value - untested crap.

As for your shopping list, add this:

https://www.sparkfun.com/products/12642

Thank you for the advice! Is that in addition to, or replacing the MEMS microphone breakout? If it helps, it will be almost completely enclosed in a plastic casing, I picked the MEMS microphone because (unless I’m mistaken) it said it would not require much of a hole for sound to get through, that it could be pressed right up against the enclosure and still get good sensitivity.

The enclosure is a 6"x6" “rounded pyramid” form. Similar to the following picture, but made of plastic.