Listen to the sound of silence. Leo Beranek, the then Director of Harvard’s Electro-Acoustic Laboratory, developed an echoless room in pursuit of such an oddity. Famed composer John Cage famously described the experience: “In that silent room, I heard two sounds, one high and one low. Afterward, I asked the engineer in charge why, if the room was so silent, I had heard two sounds. He said, “Describe them.” I did. He said, “The high one was your nervous system in operation. The low one was your blood in circulation.” Originally designed to test loudspeakers for military purposes, the concrete and fiberglass chamber has inspired modern adaptations for commercial music purposes. Mr. Beranek’s advancement in the science of acoustics inspired recording studios, manufacturers and even musical works such as John Cage’s “4’33”.”