Trace 87. A triangle wave at 741 Hz, originating from Subway Tunnel. Recorded in a cave environment, era: 1970s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #1769 — Trace 87
ID#1769
Rarity
MID:41%
Frequency
741 Hz
X-HI:5%
Wave Type
Triangle
X-HI:8%
Resonance
Metallic
EX:5%
Era
1970s
X-HI:6%
Origin
Subway Tunnel