The Black Frequency

Timestamp: 04:57 BST
Recovered from: /crypt/acoustic-archives/void-band
Status: Fragmentary recording — analysis ongoing

It begins below the range of human hearing.

Technicians working with the early Nocturnis acoustic research describe a “negative frequency band” — a signal that registers on equipment but not in air. At 0 Hz, the body still reacts: gooseflesh, shallow breath, the faint sense that someone has just left the room.

When the transmission was first isolated, playback caused brief loss of environmental detail in observers — clocks losing seconds, lights dimming imperceptibly, notes taken on paper smearing before the ink dried. One engineer described it as “the sound of absence, broadcast loud enough to feel.”

The experiment log ends mid-sentence.
Only one annotation survives:

Do not amplify. It listens back.

Spectrographic reconstruction suggests the frequency is self-modulating — each playback shifts the pattern slightly, as if learning the listener’s rhythm. Researchers nicknamed it The Black Frequency for its visual signature: a spectral void that absorbs every wavelength plotted against it.

Attempts to duplicate the conditions have failed. But reports of spontaneous recurrence continue, particularly among those who spend long hours in silent rooms.

If you think you hear it, you haven’t — yet.

Filed by: Nocturnis Acoustic Oversight Division
Note: Recording integrity 62%. Further listening discouraged.
Tag: #Fugue