If you're interested, just expose your infant/toddler kids to a lot of music. Especially complex music like classical and jazz, not just what's on the top 40 radio.
Kids' brains at that age are in peak sound processing mode. They are learning to understand the aural world. This leads to understanding spoken language. Music is just sound, and pitch can be learned like any other sound. We could speak in musical notes if we had a language codified that way.
This is more like learning phonemes. It significantly helps language acquisition to expose your children to a lot of different word sounds. Similarly, if you only play top 40 pop music or baroque music, your child likely won't be able to acquire perfect pitch.
They do, most kids learn to say words perfectly imitating what they hear, including regional accents. Of course some people have speech impediments but it's a minority.
Kids' brains at that age are in peak sound processing mode. They are learning to understand the aural world. This leads to understanding spoken language. Music is just sound, and pitch can be learned like any other sound. We could speak in musical notes if we had a language codified that way.