You know, those words that look like what they sound like. Creak. Bang. Swish. I love these guys and I use them all the time in my writing.
CreakBut not everyone likes using sounds this way. One of my beta readers absolutely hates them, but she's accepted the fact that I'm not changing it and now only points them out where they really bug her. And she's usually right.
Bob spun around. Was that a zombie or just the wind?
I find that using onomatopoeia gives me a much closer POV that describing how something sounds. Creak on its own line jumps out just like a creak in the night would. "She heard a creak" just doesn't have the same sense of intimacy. "A board creaked" is better, and I'll use that too, but it still doesn't convey what
does for me. It's like someone jumping out at you on the page. It emphasizes a sound that really matters to the scene, usually cranking up the tension and giving you that nail-baiting edge of your seat feeling you get in the movies.
And "a board creaked" can sometimes give away too much information. Does our POV really know it's a board? Can they tell what made the sound? Using just the sound gets around all those pesky POV problems.
Of course, if you happen to be like my friend and can't stand onomatopoeia, don't feel you have to use it. There are plenty of great ways to convey sound (just not as cool).