Sounds Interesting (Meta)

There are three clues containing "(1)", "(2)", and "(3)", respectively. The respective answers to each of those clues is HOLE, HART and BUT. These three words are homophones of other words (WHOLE, HEART, BUTT) when you add a letter. The letters added to create these homophones are W, E and T, or WET.

WET is also a homophone. You can form its homophone if you add an H. That word is WHET, which is the meta answer.