Noisy Neighbour

A couple of times a year there's a noise like a gigantic vacuum cleaner heard in the distance. Not very loud but noticeable all the same. It's the farmer working his fields on the opposite hill. Which he does do on this Sunday f ex, despite the local council prohibiting noisy activities on Sundays and bank holidays. His combine harvester comes out at night once a year, probably because that machine is hard to get to his field in the daytime.