Sally - not too sure I agree with the ‘Snipe’ prognosis but … go on utube and listen to the call / song of the Woodcock which is a nocturnal species. I would eliminate this one first. The Woodcock has quite a distinctive call, which ‘at a stretch’ could interpreted as a sort of baa! See what you think? Recalling bird song is hellishly difficult.
In the middle of last night I heard a bird that sounded like a sheep baaing! It flew round for some time over Kings Lane in Ashcott. I googled it and it said possibly a Snipe. Have there been sightings?