While this explains why the sounds are sharp/soft, IMO the interesting part is: why is there seemingly such a fundamental connection between "sharpness" in spoken language, and "sharpness" in our (visual) understanding of the world?
These two concepts are not fully equal, so why don't we have two different words and see them as separate concepts?
These two concepts are not fully equal, so why don't we have two different words and see them as separate concepts?