Sound effects are crucial in the creation of an environment. There are many different ways to get them. You can search online for sounds that have already been made. There is foley audio that you can create and record yourself. Finally, you can take and distort a noise in order to create something new and unique.
Searching for sounds online can provide a variety of results and cuts down on the time needed for collecting sound clips. A site like the YouTube Audio Library is a good resource for finding different types of generic clips.
Foley audio is a type of recorded audio where the creator is responsible for capturing the sound. The clip above references the foley artists that created the sounds for the movie Cloudy with a Chance of Meatballs. Using things in the environment, the artists create the sounds that line up with the animation. They make considerations for what sounds most like they think the noise would sound like. It is mentioned by the artists that the sound created using the same method as animated in the movie sometimes doesn’t provide a satisfying sound, or the sound they are looking for, so they pivot and find another way to do this.
Distorting a noise to produce another as an audio effect is done for many different reasons. In my experience, I have seen it in games. In Subnautica, there is a creature named the reefback that produces a low-pitched sound. This is thought to be the slowed vocals of an individual. To get a unique sound for this fictional creature, they needed to make something that doesn’t exist yet, which was a distorted audio, not something found online or able to be made through Foley.
The different methods used to create sound effects can be selected depending on the needs of the project. It is up to the creator to decide what would be best. With so many ways to do so, the power to create an immersive environment through sound grows.