Glen Ellen, Calif.

YEARS ago, when selective logging was first introduced, a community near an old-growth forest in the Sierra Nevada was assured that the removal of a few trees here and there would have no impact on the area’s wildlife. Based on the logging company’s guarantees, the local residents agreed to the operation. I was skeptical, however, and requested permission to record the sounds of the habitat before and after the logging.

On June 21, 1988, I recorded a rich dawn chorus in California’s pristine Lincoln Meadow. It was a biome replete with the voices of Lincoln’s sparrows, MacGillivray’s warblers, Williamson’s sapsuckers, pileated woodpeckers, golden-crowned kinglets, robins and grosbeaks, as well as squirrels, spring peepers and numerous insects. I captured them all.

When I returned a year later, nothing appeared to have changed at first glance. No stumps or debris — just conifers and lush understory. But to the ear — and to the recorder — the difference was shocking. I’ve returned 15 times since then, and even years later, the density and diversity of voices are still lost. There is a muted hush, broken only by the sound of an occasional sparrow, raptor, raven or sapsucker. The numinous richness of the original biophony is gone.

Lesson: While a picture may be worth a thousand words, a soundscape is worth a thousand pictures.

A soundscape contains three basic sources: the geophony, which includes all nonbiological natural sounds like wind or ocean waves; the biophony, which embraces the biological, wild, nonhuman sounds that emanate from environments; and the anthrophony — man-made sounds, commonly referred to as noise.