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Sound lab quietest place on Earth
By MATT MCKINNEY
MINNEAPOLIS (AP) - The quietest place on Earth makes its claim less than a block from a bustling liquor store, next to a city bus stop, under the flight path of jumbo jets, and not far from a playground that hosts a daily scream fest worthy of earplugs.
And yet, there it is: the anechoic chamber at Orfield Labs, an office-size studio used for testing sound equipment. Right in Minneapolis.
Engineers tested the chamber not too long ago and found, or rather didn't find, sound. What they didn't find measured below the threshold for human ears, 0 decibels, and was as quiet as negative 9.4 decibels, an absence so profound that a person standing in the room for more than a few minutes would begin to hear his or her own ear making noise as their brain struggled to understand what was happening.
Lab owner Steve Orfield wondered if he might have the quietest chamber in existence. He called Guinness World Records.
"Guinness had never had a claim of negative decibels so they said, 'Why don't you just call it the quietest place on Earth?"' Orfield said.
And that's how the anechoic chamber (named for a Greek word that means "no echo") at Orfield's E. 25th Street laboratory got into the latest edition of the record book.
The quietest place on earth was once the noisiest in the digital world. This was the site of Sound 80, the legendary south Minneapolis studio that pioneered digital recording using machines developed by 3M Co. The world's first production of digital recordings was made here: the St. Paul Chamber Orchestra's rendition of Aaron Copeland's classic "Appalachian Spring," and a second recording by local legends Flim and the BB's. Bob Dylan recorded parts of "Blood on the Tracks" at the company's No. 1 studio, which remains much as it did at the time of the recording. Others who passed through the studio include Roberta Flack, Leo Kottke, Cat Stevens, Dave Brubeck and Lipps.
Times changed, and Sound 80 founder Herb Pilhofer eventually sold the building to Orfield 15 years ago.
A room so quiet one could hear a pin drop is really not so quiet. Listen again and hear the throaty whoosh of air coming from the heating ducts, the buzz from a distant airplane overhead, cars humming past the window; mobile steel noisemakers. A high school physics teacher will tell you that sound travels as vibrations through air and even our quiet places are alive with sound. And that's just what we can hear. A human ear can theoretically detect sounds as low as 0 decibels, an arbitrary number that was set to match the approximate threshold of human hearing, but many adults cannot hear anything below 12 to 15 decibels. And then there's the whole range of sounds below human hearing, below 0 decibels.
It's the business of people like Orfield to pay attention to those noises.
His company engineers sound (and lighting and many other things) for companies as wide ranging as Maytag and Harley-Davidson. Talking to Orfield for a few minutes, the world of acoustics reveals itself. Nothing, it seems, has gone unstudied by sound engineers. A dishwasher, a motorcycle, an airplane engine. These inventions sound the way they do because someone somewhere thought it would mean quality, or strength, or would convince people that the machine was doing what it was supposed to do.
The problem, as Orfield explains it, is this: "How do you make a dishwasher sound very nice and sound like it's washing dishes?"
To answer such questions, Orfield sometimes uses a reverberation room, an echo chamber at his office complex, where sound lingers in the air for up to eight seconds. For others, he uses the anechoic chamber, a studio in which sound dies almost immediately. Nothing reflects off the walls. Engineers use the chamber to test microphones, speakers and hearing aids, among other things.
The chamber is sort of like a Russian nesting doll, a series of boxes place inside each other to deaden the sounds of the outside world. The first and largest box has concrete walls that are a foot thick. Inside them, a smaller room called an overchamber sits above the pit. And inside the pit, floating on steel coil springs, is the anechoic chamber. It measures 20-by-20-by-15-feet on the outside, but just 8-by-10-by-12-feet inside. Most of the difference is taken up by row upon row of 3.3-foot-long fiberglass wedges that point inward. A sound made inside the chamber travels to the walls and gets trapped inside the wedges lining the interior. Nothing reverberates. The sound dies. The result is 150 decibels of sound loss from the outside world to the chamber.
Orfield bought the chamber from a Sunbeam research facility in Schaumberg, Ill. It was loaded onto three semitrailer trucks with the help of the University of Chicago football team, then transported to Minneapolis and kept in storage until Orfield built an addition in 1995 to house the chamber.
Building an anechoic chamber from scratch costs from $100,000 to $500,000, said Jeff Morse, vice president of Eckel Noise Control Technologies, a Massachusetts company that builds them.
The company has constructed more than 500 facilities since 1952. Morse said the quietest anechoic chamber he had ever heard of was at a Hewlett Packard facility, where engineers registered minus-4 decibels. "Even getting into the negative numbers is extremely, extremely quiet," he said.
Step inside Orfield's anechoic chamber and prepare to feel confused. The human ear relies on reverberations from our environment for some of our balance. We know where we are in the world by what we hear. Sound waves bounce off the walls around us and we get a sense of how big a room is. The hush of a car's interior reminds us that we're in a cramped space. Take that pressure away and a person feels lost.
Stepping into an anechoic chamber is not like simply going somewhere that's quiet. The absence of noise, of any noise, even noises that are just below the capacity of human ears, leaves your sense of balance slightly askew.
The brain becomes so confused by the absence of pressure on our ears that it orders the ear to start buzzing, making "auto-emissive sounds," Orfield said.
It was a few moments spent in an anechoic chamber that inspired experimental musician John Cage to write 4'33", a three-movement composition of no sound. Its premiere in 1952 had pianist David Tudor sitting at a piano, the keys left untouched, occasionally turning pages as he glanced at a stopwatch.
Cage said it was his experience in an anechoic chamber that made him realize there was no such thing as silence, for even in the chamber he could hear two sounds, one high and one low. A sound engineer at the Harvard anechoic chamber told him he was hearing his own nervous system (high) and his own blood pumping throughout his body (low).
Creepy, a bit, but then standing in an anechoic chamber feels unlike anything most people have ever experienced. Not even swimming under water matches the noiseless sensation.
Orfield, for his part, said he was surprised that Guinness gave him the designation.
"I had no expectation that I would ever hear from them," he said.
By MATT MCKINNEY
MINNEAPOLIS (AP) - The quietest place on Earth makes its claim less than a block from a bustling liquor store, next to a city bus stop, under the flight path of jumbo jets, and not far from a playground that hosts a daily scream fest worthy of earplugs.
And yet, there it is: the anechoic chamber at Orfield Labs, an office-size studio used for testing sound equipment. Right in Minneapolis.
Engineers tested the chamber not too long ago and found, or rather didn't find, sound. What they didn't find measured below the threshold for human ears, 0 decibels, and was as quiet as negative 9.4 decibels, an absence so profound that a person standing in the room for more than a few minutes would begin to hear his or her own ear making noise as their brain struggled to understand what was happening.
Lab owner Steve Orfield wondered if he might have the quietest chamber in existence. He called Guinness World Records.
"Guinness had never had a claim of negative decibels so they said, 'Why don't you just call it the quietest place on Earth?"' Orfield said.
And that's how the anechoic chamber (named for a Greek word that means "no echo") at Orfield's E. 25th Street laboratory got into the latest edition of the record book.
The quietest place on earth was once the noisiest in the digital world. This was the site of Sound 80, the legendary south Minneapolis studio that pioneered digital recording using machines developed by 3M Co. The world's first production of digital recordings was made here: the St. Paul Chamber Orchestra's rendition of Aaron Copeland's classic "Appalachian Spring," and a second recording by local legends Flim and the BB's. Bob Dylan recorded parts of "Blood on the Tracks" at the company's No. 1 studio, which remains much as it did at the time of the recording. Others who passed through the studio include Roberta Flack, Leo Kottke, Cat Stevens, Dave Brubeck and Lipps.
Times changed, and Sound 80 founder Herb Pilhofer eventually sold the building to Orfield 15 years ago.
A room so quiet one could hear a pin drop is really not so quiet. Listen again and hear the throaty whoosh of air coming from the heating ducts, the buzz from a distant airplane overhead, cars humming past the window; mobile steel noisemakers. A high school physics teacher will tell you that sound travels as vibrations through air and even our quiet places are alive with sound. And that's just what we can hear. A human ear can theoretically detect sounds as low as 0 decibels, an arbitrary number that was set to match the approximate threshold of human hearing, but many adults cannot hear anything below 12 to 15 decibels. And then there's the whole range of sounds below human hearing, below 0 decibels.
It's the business of people like Orfield to pay attention to those noises.
His company engineers sound (and lighting and many other things) for companies as wide ranging as Maytag and Harley-Davidson. Talking to Orfield for a few minutes, the world of acoustics reveals itself. Nothing, it seems, has gone unstudied by sound engineers. A dishwasher, a motorcycle, an airplane engine. These inventions sound the way they do because someone somewhere thought it would mean quality, or strength, or would convince people that the machine was doing what it was supposed to do.
The problem, as Orfield explains it, is this: "How do you make a dishwasher sound very nice and sound like it's washing dishes?"
To answer such questions, Orfield sometimes uses a reverberation room, an echo chamber at his office complex, where sound lingers in the air for up to eight seconds. For others, he uses the anechoic chamber, a studio in which sound dies almost immediately. Nothing reflects off the walls. Engineers use the chamber to test microphones, speakers and hearing aids, among other things.
The chamber is sort of like a Russian nesting doll, a series of boxes place inside each other to deaden the sounds of the outside world. The first and largest box has concrete walls that are a foot thick. Inside them, a smaller room called an overchamber sits above the pit. And inside the pit, floating on steel coil springs, is the anechoic chamber. It measures 20-by-20-by-15-feet on the outside, but just 8-by-10-by-12-feet inside. Most of the difference is taken up by row upon row of 3.3-foot-long fiberglass wedges that point inward. A sound made inside the chamber travels to the walls and gets trapped inside the wedges lining the interior. Nothing reverberates. The sound dies. The result is 150 decibels of sound loss from the outside world to the chamber.
Orfield bought the chamber from a Sunbeam research facility in Schaumberg, Ill. It was loaded onto three semitrailer trucks with the help of the University of Chicago football team, then transported to Minneapolis and kept in storage until Orfield built an addition in 1995 to house the chamber.
Building an anechoic chamber from scratch costs from $100,000 to $500,000, said Jeff Morse, vice president of Eckel Noise Control Technologies, a Massachusetts company that builds them.
The company has constructed more than 500 facilities since 1952. Morse said the quietest anechoic chamber he had ever heard of was at a Hewlett Packard facility, where engineers registered minus-4 decibels. "Even getting into the negative numbers is extremely, extremely quiet," he said.
Step inside Orfield's anechoic chamber and prepare to feel confused. The human ear relies on reverberations from our environment for some of our balance. We know where we are in the world by what we hear. Sound waves bounce off the walls around us and we get a sense of how big a room is. The hush of a car's interior reminds us that we're in a cramped space. Take that pressure away and a person feels lost.
Stepping into an anechoic chamber is not like simply going somewhere that's quiet. The absence of noise, of any noise, even noises that are just below the capacity of human ears, leaves your sense of balance slightly askew.
The brain becomes so confused by the absence of pressure on our ears that it orders the ear to start buzzing, making "auto-emissive sounds," Orfield said.
It was a few moments spent in an anechoic chamber that inspired experimental musician John Cage to write 4'33", a three-movement composition of no sound. Its premiere in 1952 had pianist David Tudor sitting at a piano, the keys left untouched, occasionally turning pages as he glanced at a stopwatch.
Cage said it was his experience in an anechoic chamber that made him realize there was no such thing as silence, for even in the chamber he could hear two sounds, one high and one low. A sound engineer at the Harvard anechoic chamber told him he was hearing his own nervous system (high) and his own blood pumping throughout his body (low).
Creepy, a bit, but then standing in an anechoic chamber feels unlike anything most people have ever experienced. Not even swimming under water matches the noiseless sensation.
Orfield, for his part, said he was surprised that Guinness gave him the designation.
"I had no expectation that I would ever hear from them," he said.
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