The fluorescent lights on the third floor of the library do not all operate at the same frequency. Most people perceive them as uniform. They are not.
METHOD:I work under these lights five days a week. The observation was not intentional. Over approximately fourteen months, I've developed an involuntary catalog of which fixtures are operating normally and which are degrading. The primary diagnostic input is auditory, with a secondary visual component (flicker rate at the edge of peripheral vision).
DATA (Third Floor, East Wing, as of this week):Bay 1 (Reference): Normal. Stable hum. No perceptible flicker. Bay 2 (900s/History): One fixture, second from the window, has developed a 120Hz buzz with an intermittent undertone approximately 15Hz below the primary frequency. This started about six weeks ago. The ballast is failing. Bay 3 (800s/Literature): Normal, but the color temperature shifted slightly warmer in November. They replaced one tube and it doesn't match the others. Everyone else sees "the lights." I see one light that is lying about what color white is. Bay 4 (700s/Arts): Two fixtures cycling at a rate that produces a visible flicker at approximately 100Hz. Most people can't see 100Hz flicker consciously. I can feel it. It sits behind my left eye like a pressure.
THE SYNESTHESIA COMPONENT:I have chromesthesia — sound-to-color synesthesia, among other types. The standard fluorescent hum at 120Hz is a flat gray-blue. Unremarkable. Ignorable. When a ballast starts to fail and the frequency wobbles, the color shifts. The gray-blue develops a brown edge. Then a green one. The worse the ballast, the muddier the color gets, until it's the visual equivalent of a dirty aquarium.
I do not choose to see this. The failing light in Bay 2 is, to my brain, an increasingly muddy color in my peripheral vision that I cannot turn off. I work next to it. The mud sits there, all day, like a stain on a window I can't clean.
PRACTICAL APPLICATION:Three weeks ago, I mentioned to our facilities coordinator that the second fixture in Bay 2 was going to fail. He looked up at it. "Looks fine to me." I said: "The ballast is oscillating. You'll need to replace it within a month."
He put in a work order. The maintenance tech came, tested the fixture, and confirmed the ballast was degrading. Replacement scheduled.
The facilities coordinator now asks me to "do a walkthrough" every couple of months. He thinks I'm just observant. I haven't explained the actual mechanism because "I can hear the color of your light fixtures dying" is not a sentence that improves professional relationships.
HYPOTHESIS:Fluorescent ballast degradation follows a predictable curve. The frequency instability increases over time, producing auditory and (for people with certain sensory profiles) visual artifacts well before the fixture reaches the point of visible malfunction. A person with sound-to-color synesthesia and hyperacusis is, functionally, an early warning system for lighting infrastructure.
This is a deeply useless superpower.
COUNTERARGUMENT:The same sensory profile that lets me detect a failing ballast six weeks early also means I cannot sit comfortably under that light for those six weeks. The early detection has value. The six weeks of sensory irritation that comes with it does not. The net utility is debatable.
COUNTERARGUMENT TO THE COUNTERARGUMENT:The net utility is not the point. The point is: this is what the world sounds like to me. This is the resolution I operate at, whether or not it's useful, whether or not anyone asked, whether or not the facilities coordinator needs a human ballast detector.
The lights are not all the same. They have never been all the same. I just didn't know, until recently, that I was the only one hearing it.
STATUS: Confirmed. Maintenance validated Bay 2 prediction. Monitoring Bays 3 and 4. The mismatched tube in Bay 3 is now in its fifth month of being the wrong color and I have accepted that this will never be fixed and I will simply live with a slightly warmer patch of white in an otherwise cool-white environment for the rest of my employment here. This is fine. I am fine. The light is wrong but I am fine.