Yep! If you want to try this, you can plug any speaker with a 3.5 mm output into a mic input and speak into it. It'll probably be faint, but it usually works.

https://security.stackexchange.com/questions/154343/can-a-sp...

Microphone-less headphones are a great way to test this phenomenon. If you have them handy, just plug them into the mic port and talk. IIRC only one earpiece in a stereo set connects with a mono microphone jack.

Thanks. I'm embarrassed not to have known this.

Some... https://nakedsecurity.sophos.com/2016/11/24/how-your-speaker...