Hollow 49. A triangle wave at 20 Hz, originating from Subway Tunnel. Recorded in a container environment, era: 2020s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #1830 — Hollow 49
ID#1830
Rarity
MID:40%
Frequency
20 Hz
EX:4%
Wave Type
Triangle
X-HI:8%
Resonance
Viscous
EX:3%
Era
2020s
X-HI:6%
Origin
Subway Tunnel