Ghost sound from the past?

Regular readers will be aware of my acquaintance (MA) who experiences microsleep with REM (MWR - see here). Recently MA had a typical voice MWR. Such voice MWRs are brief snatches of voices which sound like an overheard conversation. As usual, MA was alone on hearing these voices. There were two such ghostly voices, a man and a woman it appeared. They both said just one word, 'goodnight', presumably to each other. But then something remarkable happened. There was the sound of a metal object, maybe a plate or bowl, falling on a stone floor. MA was nowhere near any such floor at the time and no actual object was observed to fall.

MA had the usual feeling of coming out of a MWR straight after the strange experience. MA was reading just before the experience. This seems to be common before a voice MWR. However there are NOT usually other sounds, only voices. It appears to be a first for MA. Someone not aware of the natural explanation for MWRs could easily interpret this experience as paranormal. So now we don't just have ghostly voices but sounds of mechanical incidents that never happened! Anyone hearing such sounds when there was no evidence any such incident having taken place might easily conclude they were witnessing a haunting! Particularly if the sound was of some object that was clearly not present. it might be interpreted as the ghostly echo of an iincident from the distant past at that location.