In the former document archives of a Seattle-based insurance firm lurks the quietest room in the world. The human ear can hear down to zero decibels. Here, the sound of silence has been measured down to negative 20. Welcome to the world of quiet, whispers Gopal Gopal, a diminutive, middle-aged psychoacoustician working for Microsofts Devices division. As he closes the door, Gopals voice changes. Im suddenly aware of the blood flow in my head. My ears ring and I swallow hard, as if rapidly descending from altitude. Hes standing beside me, but Gopals voice is struggling to pass through the air.
To get this quiet, youve got to go to extreme lengths. The entire room, which was designed by Gopal, is cut off from the rest of Microsofts Building 87 and suspended on 63 giant springs. An air gap surrounds it and the walls are so thick that were a jumbo jet to take off outside the door, the sound inside the chamber would barely be louder than someone speaking. Its a floating chamber, Gopal says, bobbing on the spot and directing my gaze towards the floor. Beneath our feet is a see-through mesh of steel cables, the same kind used to snare fighter jets landing on aircraft carriers. I look down, peering at the cones of sound-absorbing foam that continue into the gloom. The lights and sprinklers are also designed to ensure as little noise is reflected as possible. This room alone Microsofts Redmond campus has more than 20 chambers with varying degrees of quietness cost more than $1.5 million (£1.2m).
Its here, in his temple of silence, that Gopal measures the noise made by computer fans. Theres no such thing as a fan sound. There are different kinds of fan noises, he says, smiling and moving his hands through the unpleasantly silent air for emphasis. Power supplies make humming sounds. LEDs make humming sounds. When youre playing a game and the fan heats up, it makes sounds. It is when we get quieter that we begin to hear those things. To measure sound, he continues, you need to take readings in absolute silence. A room like this offers an absolutely controlled environment. Any time a sound is made, its reflected by the surfaces around you. This cuts out the internal reflections, so our measurements are pure. With an incredibly accurate measurement, you can make incredibly small adjustments. So, what else do we do with this chamber? All kinds of measurements of sound keyboard sounds, power-on and -off sounds, audio quality, Skype quality, Gopal explains.
In recent months, Gopals team has been tasked with obsessing over just one noise: the sound of a games console switching on. With the Xbox One, we got good feedback that people liked the sound when you turned it on and off. He approaches Microsofts latest games console, the Xbox One X, which is perched on a spindly table in the middle of the room. I will turn it on and tell you what weve done a bit differently, he says, pressing the button and rapping his knuckles in the air as the console lets out a rapid-fire beep... beep-beep. Do you get that? he asks, excitedly. I stare back at him, bemused. Those three tones, between the second and third, we shaved off about 25 milliseconds. You can ask: What are these guys doing? but 25 milliseconds is very significant for the auditory system. You know something changes. You get the sense of, Ah, it has speeded up. Its a teaser to say we have a faster, more powerful Xbox.