I’m not claiming everyone pronounces it that way. But he’s an ero, we need to find an ospital, ninety miles an our. You will find government documents and serious newspapers that refer to an hospital.
Likewise, when I was at school, many of my older teachers would say things like "an hotel" although I've not heard anyone say anything but "a hotel" for decades now. I think I've heard "an hospital" relatively recently though.
Weirdly, in certain expressions I say "before mine eyes" even though that fell out of common usage centuries ago, and hasn't really appeared in literature for around a century. So while I wouldn't have encountered it in speech, I've come across enough literary references that it somehow still passed into my diction. I only ever use it for "eyes" though, never anything else starting with a vowel. I also wouldn't use it for something mundane like "My eyes are sore", but I'm not too clear on when or why I use the obsolete form at other times - it just happens!
It all comes down to how the word is pronounced but it's not consistent. 'H' can sound like it's missing on not. Same with other leading consonants that need an 'an'. Some words can go both ways.
