It never fails. Lay down some kind of superlative — fastest, cheapest, smallest — around this place and someone out there says, “Hold my beer” and gets to work. In this case, it’s another, even simpler audio oscillator, this time with just a loudspeaker and a battery.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/04/30/simplest-speaker-oscillator-now-even-simpler/