Sometimes her shrill voice can be really irritating.
This is the verb version of hinder, but it's what happens when you hinder someone else enough. You'll start to irritate and to annoy them.
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:
If you want to irritate me, all you have to do is make what I'm eating sour (さわ). Did you know sour food is known to be bad for you, too? Don't make that sour face, stop eating sour things!