The use of words whose sounds make you think their meanings is called what?

The use of words whose sounds make you think of their meanings is called onomatopoeia.

For example:

* Bang, crash, sizzle, buzz all sound like the noises they describe.

* Meow, woof, moo, quack imitate the sounds animals make.

Onomatopoeia is a fun and effective literary device that adds vividness and imagery to writing.