dfreymann:
This is fantastic. Works great. Thanks!
Glad you have found a usage of this hack.
I am tracking flight noise.
I have got several sketches for Arduino and ESP32 e.g. feeding thinger.io.
Going solar is my ultimate aim, but that is really tough to achieve!
I had a prototype with a (real) 5W, 7,5V solar panel and a 6V / 20Ah battery. It did not pass the last winter and exhausted the battery on mid January. Powering continuously the 22mA required by the arduino and the SPL requires a bigger solar supply.
I also have some developments to make a weatherproof outdoor microphone that does not require any maintenance. That worked perfectly, but the PDF describing the solution is in German and suited for the old analog SPL module.
Build an outdoor microphone
Enjoy!
You might take ideas from it (the aquarium filter and the stainless spiral cleaner work great).