Here’s my requirements:
- Press a button. A sound file plays. (At least one, maybe a couple)
- The sound is loud enough to be audible. (What sort of speaker?)
- Powered by a compact battery. A few dozen plays/lasts a day is all that’s needed.
What’s the simplest/lowest power option that could play a wav file and has a few 10s of kB of space to store one? Pico? Smaller is better.