The sound of him eating potato chips is loud and annoying.
This is a single kanji with an い on the end, meaning you know it's probably an adjective. What's the adjective form of annoy? It's annoying!
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
What's noisy? That uni's rude sighing (うるさい). It just keeps sighing loudly over and over. It's sooo annoying!