The very last moment of The Chairs does nothing but raise questions. After failing to deliver the Old Man's message, the frustrated Orator exits. At this point, Ionesco tells us in his stage directions:
We hear for the first time the human noises of the invisible crowd; these are bursts of laughter, murmurs, shh's, ironical coughs; weak at the beginning, these noises grow louder, then again, progressively they become weaker. (542)
What are we to make of this? For most of the play, it's seemed pretty darn likely that there weren't any invisible guests at all. There's a good possibility that the Old Man and Woman are just imagining the whole thing to fill the emptiness of their lives. Now, though, we actually hear the invisible guests.
With this final touch, Ionesco hurls one last question at his audience, forcing us once more to question the reality of the play. Were the invisible guests there the whole time? The Orator saw them, and he seemed real. Then again, he may have just been the old couple's hallucination. The play could be taking us along with them, as they descend even deeper into their dream world. There's no way to know for sure what's real and what isn't in the play. Then again, how do we know if anything is real at all? We have a feeling this is just the sort of question that Ionesco wanted his audiences to ask themselves as they left the theater.
It also seems significant that the playwright requires the crowd noise to steadily get louder, then fade away. Perhaps this rise and fall is meant to symbolize the way we human beings grow and progress through life only to fade away into death. Notice also that these sounds happen in the midst of apparent emptiness. The chairs are all vacant and "the main door is wide open onto darkness" (542). It could be that the crowd noise in the darkness represents the Existential view that we live our absurd little lives in a universe that is ultimately mysterious and unknowable.
We should also note that the original production of the play ended a little sooner, with the Orator mumbling nonsense. We have no idea why the original director chose to end the play this way, but, in our minds at least, he robbed his audience of one the coolest, most thought-provoking moments in the script. Tsk, tsk, director guy.