Mini creatures with mighty voices know their audience and focus on a single frequency

The coquí frog, *Eleutherodactylus coqui*, is loud enough to wake people at night. Éktor/flickr, CC BY-NC-ND

In the cloud forests of South America, amid the constant cacophony of bird and insect noise, a deafening blare pierces through the background from time to time. Belonging to the loudest known bird, the white bellbird, Procnias albus, this sound would be painful to humans listening nearby and capable of causing immediate hearing damage from about a yard away.

Listen to the world’s loudest bird call.