Writing sounds in your book is important for the immersion aspect that it will give to your reader and should not be taken for granted.
Step One: Don’t forget to write sounds in the first place!
What I meant for ‘not get taken for granted’ is, when we write we often assume that by describing a scene the sounds automatically get filled in our reader’s ears. That may not often be the case, and they usually need some help with that. The addition of a single word in your sentence can change the entire feeling that it produces.
There was thunder outside
Thunder rumbled outside
It IS usually about adding one word!
Much like in the example above, I want to stress on the fact that instead of separating sounds and actions, you can often describe things in sounds.
Instead of saying “The steak was cooking. It was making a pleasant sizzling sound.” You can literally say “The steak was sizzling.” In this case it’s obvious that it’s cooking, and you’ve implanted the sound into your reader’s ears.
Another few examples could be:
“The loud hammering disturbed his neighbors.”
“The puppy went bark bark!”
“The unpleasant static from the radio made him cover his ears.”
“It was silent as snow.” (No sounds, or still air, is a very powerful sound itself!)
Describe sounds through their consequences
In the case of the radio making him cover his ears, I did not in fact describe the sound of the radio, but what I did describe is a consequence of it. He covered his ears, which made the reader imagine that the it was the unpleasant static white noise that was emitting from it.
Some sounds just need an extra piece of description to them, but I would only leave these for important scenes. For unimportant scenes, I would utilize the one-word method above. (My favorite example that I keep referencing is “he placed down the cup with a soft click”)
So for important scenes, when an explosion happens or a giant monster roars, you want to focus on their consequences the most. As I mentioned in How to Describe Action Scenes. This utilized the technique of painting a picture in your reader’s minds without actually describing what is going on, and the same can be used for sounds.
“The explosion blinded me and made my ears scream in pain before it faded into being completely deaf.”Shows a good first person perspective of what it’s like to be right next to an explosion.
Obviously, don’t overdo it
You don’t need to add sounds in everything your characters do, but throwing it here and there should be seen as adding seasoning to your food, or putting on some perfume on a well dressed individual. Adding too much becomes overbearing, too little goes unnoticed, and just the right amount is just right!