Groan 70. A triangle wave at 440 Hz, originating from Subway Tunnel. Recorded in a open air environment, era: 2010s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #0960 — Groan 70
ID#960
Rarity
X-LO:78%
Frequency
440 Hz
X-HI:7%
Wave Type
Triangle
X-HI:8%
Resonance
Crystalline
X-HI:5%
Era
2010s
X-HI:7%
Origin
Subway Tunnel