Grain. A fm wave at 440 Hz, originating from Subway Tunnel. Recorded in a corridor environment, era: 2010s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #0387 — Grain
ID#387
Rarity
HI:21%
Frequency
440 Hz
X-HI:7%
Wave Type
FM
EX:4%
Resonance
Dense
X-HI:6%
Era
2010s
X-HI:7%
Origin
Subway Tunnel