Tunnel’s Extraordinary Resonance

Guinness World Records has certified the findings made by Trevor Cox, Professor of Acoustic Engineering at the University of Salford. A gun shot fired inside the tunnel resonates for a full record 112 seconds.

Typical reverberation times at mid-frequency:
Living room: 0.4 seconds
Opera house: 1.2 seconds
Concert hall for classical music: 2 seconds
St. Paul’s Cathedral: 9.2 seconds

Full article: Acoustic scientists shatter the world record for longest ever echo