a human a huge rock a hidden box a house but an hour

The "H" sound counts as a consonant, so you use "a". That's the basic rule. If you drop the "H" - and you'd need a very good reason to do so! - your options are to use "an" ("a-noo-man", which sounds a little weird) or a glottal stop. The use of "an" depends on spoken (not written) English.

Actually, it's "a human" not because "h" is a consonant but because it has the vowel "u" that sounds like "you". If the vowel after the "H" doesn't sound like that, then you must use "an" because the "H" is a silent consonant

Hello there! To answer your question, it is "a human," because "h" is not a vowel. As they say, the vowels are a,e,i,o,u, and sometimes y.