Why does your own voice sound strange when you hear it on a recording?

Answer: You normally also hear it through your skull bones

Recordings speed your voice up slightly — Recordings play back at the speed they were made, so your pitch isn't changed. The difference is that you're used to hearing extra deep tones that reach you through your bones.

You normally also hear it through your skull bones ✓ — When you speak, you hear your voice through the air and also as vibrations traveling through your skull, which boost the deeper tones. A recording carries only the airborne sound, the version everyone else hears, so it sounds higher and thinner to you.

Speakers distort every voice the same way — Good speakers reproduce voices closely, and other people's recorded voices sound normal to you. Only your own sounds off, because you've never heard it without the part carried by your bones.