

A pet parrot was the sole witness to a murder and began repeating what's thought to have been their last conversation, including the words: "Don't shoot!".
the Mayan people constructed the temples in a way that a handclap at the base of the temple produces an echo that sounds like the call of the sacred Quetzal bird.
Echo is always a play against the inactivity of matter — echoes cover more space on still than on running water. The voice ricochets more in a rock-strewn woodland. Hardwood buildings are more resonant than softwood buildings.

Echo is a always a play against the inertness or voicelessness of matter; Just watch how echoes rise and lower in an auditorium according to the attention of the audience.

Echo is the effect of the voicelessness of matter. The more inert a substance, the louder will echo thunder against its walls