Answer:
Sometimes, poets use enhance their descriptive prowess by appealing to our sense of smell, touch, sight, taste or hearing by intentionally selecting and using certain words. This technique in literature is referred to as Imagery.
1. With respect to the poem by John Betjeman "Harrow-On-The-Hill", we see a repeated use of words with relate to hearing. For example, in the third line he states:
"The poplars near the stadium are <em>trembly</em>"
And in the fourth line he writes,
"With their <em>tap and tap</em> and <em>whispering to me</em>"
He uses this imagery to paint a picture of Autumn (the period of the year just before winter when the weather transitions from a warmer climate to a cooler one). It is clear from the Johns depiction that it is still Autumn but it's nearly winter. A trembly and whispering poplar suggests that the weather was windy.
2. In the third line of the second verse he writes:
<em>"And the constant click and kissing of the trolley buses hissing"</em>
Again we see the use of visual and auditory imagery by the use of the words highlighted above.
From this line, it's easy to tell that John is trying to describe the busyness of the rocky island.
See also the words <em>rumble</em>, and <em>thunder</em> in lines 5 and 6 of verse two which appeal to hearing.
3. In verse 3, we see words from lines 1 & 2 which appeal to what can be seen. Line 5 is a great example of visually captivating imagery. It states:
<em>"Can those boats be only roof tops"</em>
When trawlers are very far from harbor, they appear tiny and sometimes, only their roofs can be seen from such a distance.
John captures the scenery with his line above.
In summary, John uses a lot of auditory and visual imagery in his poem "HarrowOn-The-Hill".
Cheers!