Keen 66. A sine wave at 528 Hz, originating from Subway Tunnel. Recorded in a vacuum environment, era: 2000s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #2639 — Keen 66
ID#2639
Rarity
MID:41%
Frequency
528 Hz
X-HI:6%
Wave Type
Sine
X-HI:13%
Resonance
Metallic
EX:5%
Era
2000s
X-HI:8%
Origin
Subway Tunnel