[aninhumer]

>there are tonal languages, after all!

I believe most (if not all) natural tonal languages use relative pitch, not absolute, so you wouldn't need perfect pitch to understand them.

[jtheory]

Huh; quite right. I've had it in my head for several years that Thai, at least, was tonal based on absolute pitch; but it looks like that's wrong.

I did turn up that a much larger percentage of people have perfect pitch in populations that speak tonal languages.