Answer:
alliteration - <u> Bouncy balls for bonny babies.</u>
hyperbole - <u>These headphones are the future of listening.</u>
simile - <u>Ice cream so fresh it's like eating fruit.</u>
onomatopoeia - <u>This kitty litter will make your kitty purrrrr.</u>
Explanation:
Alliteration is the repetition of sounds or letters at the beginning of words that are close to each other in a structure. Notice that that's what we have in "Bouncy balls for bonny babies" with the repetition of the b's.
A hyperbole is a figure of speech in which exaggeration is used to give emphasis to the message the speaker wants to convey. In "These headphones are the future of listening," the affirmation is quite ambitious and, honestly, impossible to prove. It is a hyperbolic affirmation.
A simile is a figure of speech used with the intention of making a comparison - stating a similarity - between two different things. It uses words such as "as" or "like". That's what we have in "Ice cream so fresh it's like eating fruit," in which the freshness of the ice cream is compared to the freshness of fruit.
Finally, onomatopoeia refers to words that represent a sound by imitating it, such as bang, crash, click, buzz etc. In "This kitty litter will make your kitty purrrrr," purrrr is imitating the sound made by cats when they are happy.