Every echo implies a ghostly alter-ego hidden behind the reflecting surface

Evidence

But echo suggests a still deeper mystery. Acousticians will explain that the reflection of a sound off a distant surface is simply a case of the original wave bouncing back, the angles of incidence and reflection being equal. In order to understand this effect one may project a mirror image of the original sound deep behind the surface, at exactly the same distance and angle from the surface as the original. In other words, every reflection implies a doubling of the sound by its own ghost, hidden on the other side of the reflecting surface. This is the world of alter-egos, following and pacing the real world an instant later, mocking its follies. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 717

Categorization

• FICTION: The idea of sound’s ghost alter-ego mocking the real world is rich material for supernatural or speculative fiction.
• DEFINE: Explains the mirror-image model acousticians use to describe reflection, rendering it poetically.
• corroborated: 2 independent passages support this claim — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 717
• XREF: connects to: An echo is partly an original sound from the reflecting material — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 927; Dead rooms strip echo, disorienting spatial self-location — Jamal Awil, The Whispering Archive: The Complete…, 113; The shadow, like the mirror image, carries away all reality from the body. — Jean Baudrillard, Simulacra and Simulation, 489 (+2 more)