Written by Jack Evans, Asheville Watchdog.
Humans may prize nature for notions of quietude, for serving as a refuge from highway buzz and construction grind and office chatter and the anxieties that accompany them. “I go among trees and sit still,” begins one poem by the late writer and environmentalist Wendell Berry. “All my stirring becomes quiet / around me like circles on water.” But even peaceful forests keep their secrets: Beyond the limits of homo sapiens’ hearing teems a world of noise, loud as jackhammers or jet engines — “complete chaos,” said Steve Goodman, a wildlife research program manager for the National Parks Conservation Association.
Bats, who generate much of this ultrasonic clamor, have evolved with distinct inner-ear structures that allow them to echolocate expertly among the din. And humans have developed a way to see what they can’t hear, via spectrograms, which visualize recordings of bats…