Onomatopoeia, sometimes called “imitative harmony,” is the forming of words that imitate a sound and that are associated with the object or action making the sound. The term is derived from the Greek word onomatopoeia, which means “the making of words.”
For example, in “clanging of the bells,” clanging is a word that sounds very much like the sound a bell makes when it's rung. The word crackle sounds like the sound a fire makes, or the rough noise we hear when something stiff is folded or broken. Whoosh sounds like the noise we hear when something speeds by. Meow is just like the cry a cat makes. All of these are pretty familiar forms of onomatopoeia, but poets and prose writers alike use inventive forms of this tool to add a further dimension to their work. In fact, you may want to create some onomatopoeic words of your own — try reading Lewis Carroll's poem “Jabberwocky” for inspiration.
Consider using words like gush, mumbling, whirr, and plunk. These onomatopoetic terms will add sensory detail as well as provide readers with more complete understanding.