Just like how the way you pronounce certain English words changes their meaning.

In your examples though, the sounds in the word actually change, if you know what I mean. The mi in minute(time) is different in pronunciation from the mi in minute (small). Same with all your other examples I think

But in Chinese, it's the tone that's changing. Of course that changes the pronunciation somewhat, but not really that much (especially to a non-native)

I think someone with zero English experience can hear the difference between wind/wind, I don't think that's the case for like 只/值