In 2014, acoustics expert Trevor Cox crawled through a narrow pipe into a subterranean oil tank in Inchindown, Scotland. One gunshot and 75 seconds later, he had set a new world record for the longest echo in a man-made structure. Learn more about reverberation time, and listen to the record-holding gunshot in the underground chamber.
*According to the International Standards Organization (ISO), the definition of reverberation time is the time that a sound takes to decay until it is 60 dB below the level of the initial impulse sound.
Listen to Trevor Cox playing his saxophone with the world's longest echo:
Learn about Trevor Cox’s dedication to amazing sound phenomena in our expert profile article