[pessimizer]

I researched this a while back, and it turns out that while they can't hear tones (if you play minimal pairs in isolation, they won't be able to hear the difference), they still understand people and reproduce them correctly when they speak. They can also be trained to recognize recognize the difference. There's really no such thing as tone deafness.

Tone deafness is when you sing something badly, people make fun of you, and you stop trying to sing. Not an option when you speak a tonal language, instead you just learn pitch without realizing you're learning pitch, just operating from "feelings" and what "sounds right," which is of course based on an enormous amount of lifetime feedback.

It's like how actual blindsight (when the eyes or their connections to the brain are actually damaged or destroyed) is unrecognized echolocation. We are not aware of our own conscious experience, or the processes we go through to reach some of then conclusions we reach.

[watwut]

That is not true. I know person who cant tell piano keys from each other almost as far as an octave. She cant tell whether you you have hit one or two at the same time. She cant tell whether you have hit different one you you play two keys consecutively. She does hear well.

That is tone deafness and it has zero to do with singing. Tone deafness is not measured by having people sing.