Ping 68. A sawtooth wave at 440 Hz, originating from Subway Tunnel. Recorded in a membrane environment, era: 1990s. One of 5555 echoes — sounds no one thought to save.
Name
ECHO #4720 — Ping 68
ID#4720
Rarity
LO:62%
Frequency
440 Hz
X-HI:7%
Wave Type
Sawtooth
X-HI:9%
Resonance
Brittle
X-HI:6%
Era
1990s
X-HI:9%
Origin
Subway Tunnel