Here is the etymology of an-
an- is a privative prefix, signifying absence from and comes from the Greek an-, meaning not or without, the Greek prefix being a fuller form of the one represented in English by a- or an-, which is a later form of the Latin ad meaning to, before -n-, as in annex, announce, annihilate
Echo you know.
“The anechoic chamber in Building 87 was constructed with six layers of concrete and steel, which all rest on damping springs in the floor to eliminate nearby vibrations. Fiberglass wedges cover the walls and ceiling, designed so that sound waves get trapped in their purposeful geometry and dissipate.
“The result is a room that is -20.35 decibels. Yes, negative. Any sound pressure that dips below the threshold for human hearing is represented as negative decibels.
“For comparison, the sound of breathing has been measured at 10 decibels, while the sound of air molecules colliding in a gas or liquid (known as Brownian motion) is -23 decibels. At the other end of the extreme, a rock concert may be 110 decibels.
“In Microsoft’s chamber, the subtle sounds of the human body — breath, circulation, digestion, heartbeat, joint movement — become undeniably audible, and the rustle of clothes sounds like the roar of the ocean.
“In other words, inside this anechoic chamber, your body creates its own soundtrack.”
All the foregoing was courtesy of interestingfacts.com.
What a weird corporation is Microsoft. Too much money, not much sense.
If you want to go on a tour, go here https://nypost.com/2023/02/02/inside-the-worlds-quietest-room-at-microsofts-headquarters/ Then stop. A subsequent run of videos is irrelevant.