N° 009 2026.04.22

the absent fundamental

不在の基音

On a telephone, the bass of a male voice — around 100 Hz — is not actually present. The line cuts off below 300 Hz. And yet you hear the pitch. You hear the speaker as themselves, with all the low warmth of their throat intact. None of that is in the signal.

What's happening is that the brain is assembling a fundamental from the overtones it does receive. A virtual pitch — a perceived low note constructed from the upper harmonics that imply it.

The same trick lives in pipe organs, with no electronics involved. To reach a 32-foot note without a 32-foot pipe, organ builders combine a 16-foot pipe with one tuned a fifth above it — 10⅔ feet. The two sound together, and the listener hears a phantom pitch one octave below the 16-foot. The Resultant Bass. The 32-foot is in the room without ever being played.

Both the phone and the organ are doing the same thing. Each is solving an impossibility — the low frequency cannot be sounded directly — by hinting at it through what can be sounded. Different centuries, different physics, the same psychoacoustic move.

This is a solution that lives on the listener's side. Rather than adding something new, it borrows a circuit already humming in them. Accept the constraint. Find the route hidden inside it.

I have been building a small tool, absentia, on this principle. It asks the question more openly than usual — what if the music is the partials of a fundamental that is never sounded? The note you most strongly hear is the one I never play.