Answer:
The noises the kid made when he knocked on the door were, "boom bang bam".
Step-by-step explanation:
First, let's start with what alliteration is
Alliteration = the occurrence of the same letter or sound at the beginning of adjacent or closely connected words.
Since boom, bang, and bam all sound the same at the beginning this is an example of an alliteration.
I hope this helps you out :D