Sigh. A sawtooth wave at 220 Hz, originating from Subway Tunnel. Recorded in a cathedral environment, era: 2010s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #1434 — Sigh
ID#1434
Rarity
MID:42%
Frequency
220 Hz
X-HI:8%
Wave Type
Sawtooth
X-HI:9%
Resonance
Crystalline
X-HI:5%
Era
2010s
X-HI:7%
Origin
Subway Tunnel