How many bards gild the lapses of time!

After reading this poem, it is fairly clear that nature has a profound influence on Keats and his poetry writing. He cites the "the songs of birds - the whisp'ring of the leaves - the voice of the waters..." as influences to his work (or whenever he "sits down to rhyme"). However, one aspect of this piece did interest me, what is "the great bell"? Obviously, it is a man-made object, something forged from metal, so it is not a pure symbol of nature. But, Keats includes it in his natural influences. Is he suggesting that the sound that the bell makes represents the harmony between nature, in this case: the wind, and humanity, in this case: the man-made bell? Is it the bell a symbol of the beauty that can come from intertwining man and nature? If so, is it more influential that the symbols of nature alone (such as the sound of water and leaves), since it is incorporating a harmonious relationship between two sides that, at times, contrast one another?