The song of a winter wren falls above 4,000 Hz, as does the music of many songbirds. Yosemite Falls, Rialto Beach, and Mississippi Valley thunder resound well below 2,000 Hz. Appreciation of these sounds, which fall outside the range of human speech, remain unvalued and unprotected. No wonder many Americans are becoming deaf to Nature.

Gordon Hempton, John Grossmann, One Square Inch of Silence-…, loc. 1095