Onomatopoeia is not as difficult to use as it is to spell. Ticktock, ticktock, Chattering, Boom! are a few words that come to mind. Read one or two comic books, and you will find more than a handful of these words. Additionally, the sounds animals make are likely to have onomatopoeic words in any particular language. Goats bleat, Donkeys hee-haw, Owls hoot and so on.
Much like consonance and alliteration, onomatopoeias are known to spice up your writing by making words more compelling and interesting to your reader. Let's look at the following sentence;
As David lay on the mat, he could hear the constant mews of the cat in the next room.
As David lay on the mat, he could hear the constant disturbing sounds of the cat in the next room.
Both words may seem to confer the same message, but read between the lines slowly and carefully and you'll get the effect of the onomatopoeic "mew" sound in the first sentence. Just as pictures help your readers to better capture a graphic message, onomatopoeic sounds are perfect when sending a stronger impression of a particular feeling or condition. They literally let your readers "hear" what you are writing.
For example, the "mew" sound better represents the sound that cats make and will likely capture the attention of the reader to your writing than modifiers would.
Just in case you don't really believe the effect of onomatopoeias, have you heard of the phenomenon called sound symbolism? This phenomenon describes the tendency for certain word clusters with identical meanings to share particular sounds.
For example, words like glitter, glimmer, glare, glow, etc. will easily come to mind and are good choices to describe something in writing that shines brightly.
How about rough, rugged, rocky ragged? They are likely to send vibes of something that can withstand and cruise through uneven surfaces right? That's the idea behind onomatopoeias.
Research is constantly ongoing to determine the link of certain words and the corresponding sounds they infer. A study conducted in 2001 by Edward Hubbard and V.S. Ramachandran where English and Tamil speakers in the U.S. and India respectively were shown pictures named Bouba and Kiki. Asked which of the pictures was Bouba, and your answer is as good as mine. Bouba! A whopping 95 to 98 percent of respondents also chose Bouba. The connection is apparently there. So, play around with onomatopoeia in your next writing and get your readers into the groove. Boom!