Before we answer the question, let's define what an Onomatopoeia is:
An Onomatopoeia is a word that is used to resemble or mimic the source of the sound it describes. These are great literary devices, especially in poetry, to convey realism in depicting a subject or a character.
Now there are different types of Onomatopoeia.
Direct- which resembles the exact sound, like zoom, swish, or bang.
Associated - means the words that resembles a sound associated with it. Like thud, cuckoo, or splatter.
Exemplary - means the onomatopoeia that describes the physical movement or work used by a speaker when describing a word that matches its meaning. Examples are: mumble, and dart
In the poem, we can say that the following are onomatopoeic:
1. Mewling (Exemplary)
2. Whining (E)
3. Sighing (E)
4. Whistles (A)
These are the only onomatopoeic words in this poem.