My Melancholy Blues. Question about the intro

. In the NOTW version of MMB there is a sound in the beginning of the song, it sounds like a part of a bit of a metronome or is a mistake of the mix, maybe it wasn't cut from the recording session. I could never decipher what is. Someone could?

Thanks!

listened and listened.it could be anything from a door closing ,to brian slipping his clogs of.
from a split second click,it could be anything.