Hearing didn't develop in humans. We inherited it. Trying to figure out why that was more useful than any other signal out there our ancestors could have develo

Hearing didn't develop in humans. We inherited it. Trying to figure out why that was more useful than any other signal out there our ancestors could have developed the capability to perceive is inherently just spitballing. We can't possibly know. But at minimum, it is fairly simple to also create sound. As far as I know, hearing predates vocalization, but once a species learns the latter, the former becomes a lot more useful and is going to stick around. Other animals can perceive magnetic fields, by the way. This is at least used by deep sea predators that live in the dark who sense the presence of prey by the electricity their bodies generate. Migratory birds use the earth's magnetic field to navigate long distances. It would appear neither of those use cases was enough of a killer app for our ancestors and thus didn't stick. Product market fit is all about filling the right niche at the right time. Plenty of great ideas don't make it that could have in other circumstances. And, of course, as other comments pointed out, though we don't perceive magnetic fields, we do perceive electromagnetic waves. That's what light is.