Psychological Experiment
Props:
1 apartment or small living space
1 recording (23 hours of clock's tick-tock sound, cut slightly so that it is just occasionally "off." See Lord Vetinari's office clock in the Discworld books)
1 silent analog clock
1 volunteer
Process: Volunteer knows that they are being studied for a psychologcal experiment, What they don;t know is what the experiment is. Place the recording, looped, in the silent analog clock (so the sound of the clock itself does not interfere with the recorded sound). Remove all other analog clocks from the area (thus the reason for the small space). Wait for a reaction.
Proposed possible results of experiment:
-Subject becomes increasingly paranoid, possibly believing that house is haunted
-subject becomes uneasy, and eventually depressed or easily confused
-subject realises the clock is off, and that that was the purpose of the experiment
-subject does not react, and for all outside observation appears to be unaffected

Of these, or any other reaction, what do you think you would eventually do? I think I would obsessively search for the center of the experiment, and later the source of my unease, until I either realised it was the clock (likely, if it's an experiment that I have thought about previously), or become paranoid, or possibly even convinced of a paranatural force causing the apartment to be posessed or haunted. What do you think the effect would be on you?