Every sound in a scene adds to the story. Sounds create setting, mood, character, and can provide tension. Like endowed objects, there can be endowed sounds—a sound that means more than merely what it sounds like.
Keep a list of human nonverbal sounds, and a list of nonhuman sounds that might be heard, and use them in your writing. Here’s a start…
Cry of a baby
Wind through a maple tree in autumn
Now for extra fun—especially if you are writing picture books—try to write the actual sound in words, making them onomatopoeic as possible. Margaret Wise Brown loved to do this in her books The Noisy Book and The Quiet Book. The sound of a truck going over a dirt road: burrippity burrp burrppity. Or the sound of a car siren: Err-u-ahh-err-u-ahh.