A perfect unchanging sound would be perceived as silence.

Evidence

All the sounds we hear are imperfect. For a sound to be totally free of onset distortion, it would have to have been initiated before our lifetime. If it were also continued after our death so that we knew no interruption in it, then we could comprehend it as being perfect. But a sound initiated before our birth, continued unabated and unchanging throughout our lifetime and extended beyond our death, would be perceived by us as—silence. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 881

For a sound to be totally free of onset distortion, it would have to have been initiated before our lifetime. If it were also continued after our death so that we knew no interruption in it, then we could comprehend it as being perfect. But a sound initiated before our birth, continued unabated and unchanging throughout our lifetime and extended beyond our death, would be perceived by us as—silence. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 881

Categorization

• SEED: The paradox that perfection reads as silence could anchor a meditation on why stillness marks transcendence.
• FICTION: The image of a sound lasting beyond our death reads as a poetic motif usable in speculative fiction.
• QUESTION: Is this claim testable — e.g. are there truly constant environmental tones humans habituate to and stop perceiving?
• corroborated: 3 independent passages support this claim — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 881
• XREF: connects to: Cage’s silence turns out to be not an absence of sound but an opening to unintended yet palpable sounds that saturate our perceptual field. — John Cage and the meaning of his silent piece; No part of a sound is ever truly stationary — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 444; Silence is nothing merely negative; it is not the mere absence of speech, but has a kind of Being of its own. — The Being of Silence (+7 more)