Stories tagged sound

Jun
21
2013

Tired of the constant din and bustle of modern life? Is the noise of screaming children or the neighbor's yapping miniature collie turning you into a nervous nelly? Maybe what you need is a place where you can go for some real top-notch peace and quiet.

That place could very well be the special anechoic chamber located at Orfield Laboratories right here in the Twin Cities. The chamber, which is hidden behind two vault doors, has 3.3-foot-thick fiberglass sound-deadening fiberglass acoustic wedges covering all of its flat surfaces, so instead of bouncing off the walls, ceiling, and floor as in a traditional room, any sounds are absorbed. I'm talking absorbed almost completely - the double-walled steel and concrete room is, in fact, 99.99 percent absorbent. That's a lot of quiet! Humans can't detect any sound registering below 0 dBA, and the Orfield chamber has a decibel rating of −9.4 dBA! The space is so soundproof it's listed in the Guinness Book of World as the "Quietest place on the planet."

Of course, there are some side effects to being thrust into utter silence. One is that the sounds inside your own body, your breathing, stomach gurgles, and of blood rushing through your veins become quite pronounced. "In the anechoic chamber, you become the sound," says lab president and founder Steven Orfield.

Be aware that it's not that easy being in a totally silent environment. The longest anyone has been able to withstand the sensory deprivation of the chamber is 45 minutes. And even short spells of dead silence can trigger hallucinations. The brain just doesn't like being deprived of sensory input.

Orfield's anechoic chamber has been used by several industries, including Harley-Davidson, Whirlpool, and airlines to test product sound levels, and by NASA to test the ability of astronauts to function in the extreme silence of space where, as they often say, no one can hear you scream.

SOURCE and LINKS
Story at Geek.com
Sensory deprivation causes hallucinations
Frequency range of the human ear
Gizmodo story

Apr
11
2011

Take a break and listen to the sounds around you. What do you notice? Is there anything surprising that you've been tuning out? How do the sounds change over time, and do they improve or degrade your well-being?
Do you hear what I hear?: Way up in the floor, Omnitheater...
Do you hear what I hear?: Way up in the floor, Omnitheater...Courtesy David Benbennick

It's easy to think of sound as a side-effect of important behaviors like communication, transportation, building stuff, etc. But could sound be important all on its own, worthy of our attention? We all live within environments of sound, and so do animals. In fact, there's a emerging field called soundscape ecology, which aims to study sound and its relationship with ecosystem health.

Traditionally, studies focus on the sound of one animal to understand its communication. For example, one scientist recently decoded prairie dog-ese.

But soundscape ecologists don't look at individual animal sounds so much as the bigger picture--they want to know which animals are loud or quiet, which ones have higher or lower pitches, which animals follow the sounds of other animals, and then they try to put it all together to understand the soundscape as a system that shows how animals interact with each other through sound. They also want to understand how human sounds impact these soundscapes.

Researchers compared bird life around noisy equipment that compresses natural gas with similar — but quiet — habitat. In Alberta, they found that birds had fewer offspring at the noisy sites. Similar results came from the Southwestern U.S.

Eee: my bat-dar doesn't work in loud environments!
Eee: my bat-dar doesn't work in loud environments!Courtesy Stahlkocher

Species that use echolocation, such as bats and (potentially extinct) Yangtze river dolphins, have trouble locating prey and moving safely through their habitat when unexpected sounds disrupt their echos.
Tamarin: My cage is alive with the sound of muuuusic!
Tamarin: My cage is alive with the sound of muuuusic!Courtesy Helenabella

Musician David Teie has even shown that he can create music that impacts the moods of tamarins.

And then there are the impacts of human sound on humans. Garret Keizer writes in his book, The Unwanted Sound of Everything We Want, that he "chose to write a book about noise because it is so easily dismissed as a small issue. And because in that dismissal I believe we can find a key for understanding many of the big issues."

I'm loud: how often do you see me flying low over nice neighborhoods?
I'm loud: how often do you see me flying low over nice neighborhoods?Courtesy John Pozniak
Keizer distinguishes between sound and noise, which is unwanted sound. He discusses how soundscapes are divided up according to wealth and sociopolitical power--that there are people who make noise and people who listen. Airports or loud factories might be built near less affluent neighborhoods, for example. Keizer asks us to recognize that the sounds we make can have impacts beyond us:

A person who says “My noise is my right” basically means “Your ear is my hole.”

So sound can be an indicator of larger social issues or ecological disruptions. As you read this, do you notice anything about the sounds around you that make you think of a bigger issue or problem?

The mystery of why thousands of dead blackbirds were found in a small town in Arkansas on New Year's Eve has been solved. Loud sounds, possibly fireworks, scared the birds from their roosts, sending them into a panic that led them flying into house and in some cases, directly into the ground. Here's the initial video report of the event:

And here's the latest news story.

Jun
14
2010

I'm sure there's a lot of jokes I could make about stereotypical tensions between nerds and jocks, but there's science to be had at the World Cup, and I'm never one to back down from an exercise in applied physics.
Vuvuzelas: Fans raise their vuvuzelas in celebration of soccer season
Vuvuzelas: Fans raise their vuvuzelas in celebration of soccer seasonCourtesy Manuguf

If you've been watching any of the matches on TV or have any friends that are, you may have heard about the controversy centered around a popular fan item - the vuvuzela. Vuvuzelas are plastic trumpets used by soccer fans in South Africa to cheer on their team and goad the opponents. When blown, they can achieve decibel levels upwards of close to 130 dB. That's as loud as a loud rock concert or a jet at take off.

It's gotten to the point that referees and coaches want the horns banned, and fans at home are complaining that the noise is drowning out network commentary.

Now for the science. Editors at the German blog Surfpoeten have pointed out that because the horn has a simple acoustic fingerprint (tones at 233, 466, 932, and 1864 Hz), very basic filtering software can remove the vuvuzeula drone from broadcast media (original German link). This may not prevent the players on the field from having to endure the noise, but it could at least help out the estimated 125 million people watching at home (per match).

This same idea may be in use in technology you own. Noise cancelling headphones have been around for a while. They sample ambient audio around you and play an opposing wave to cancel it out. Much like with the vuvuzelas, monotone sounds such as lawnmowers and airplane engines are the easiest to block.

May
24
2010

The theremin: An apropos sign adorns the instrument at the Bakken Museum of Electricity in Minneapolis, MN, since it can only be played by not touching it.
The theremin: An apropos sign adorns the instrument at the Bakken Museum of Electricity in Minneapolis, MN, since it can only be played by not touching it.Courtesy Mark Ryan
Anyone who has ever watched a 1950s science fiction film has probably heard the eerie emanations of the electronic instrument known as the theremin. It’s that high-pitched wavering tone that usually accompanied radioactive giant insects, or flying saucers and spacemen (e.g. The Day the Earth Stood Still). It can also be heard creating the good vibrations in the Beach Boy’s song of the same name, I remember seeing Simon & Garfunkle in concert a few years back, and noticing that the instrument was used during the performance of their song The Boxer.

I don’t remember when I first became aware of the device. I suppose it was in those aforementioned sci-fi movies. The electronic instrument (the first of its kind) was created by Russian professor Leon Theremin in 1917, when he stumbled upon it while trying to construct a better radio. Theremin was also a musician and obviously saw potential in his accidental invention.

The theremin is an odd-looking thing made up of a box containing circuitry, some knobs, and two metal antennas, one straight, and the other looped. Rather than strumming, bowing or hammering strings, or blowing air into brass tubes or across reeds, the sounds of the theremin are produced by not touching it. Here’s how it works: inside the theremin’s circuitry guts, two radio frequency oscillators produce two distinct signals. It’s the mixing of these two signals in a process called heterodyning that create the theremin’s sounds. The performer stands near the unit and controls the pitch and volume by moving their hands in the vicinity of the two antennas. Generally, the left hand controls the volume over the looped antenna, and the right hand the pitch near the straight antenna, although some performers, such as virtuoso Pamelia Kurstin, reverse the antennas (I’m guessing the instrument can be constructed for both right-handed and left-handed people). Changes in pitch and volume are controlled by the performer moving his or her hands nearer or farther from their respective antenna. In Kurstin’s case, the closer her left hand moves towards the straight antenna, the higher the pitch in tone, while the farther her right hand moves from the looped antenna, the louder the volume. Musical techniques such as vibrato and staccato can be mastered and controlled by rapid hand movement,

In this TED Talk performance (which got me interested in this subject), the above-mentioned Pamelia Kurstin shows that the theremin is not limited to just special effects. She has mastered the instrument to the point of being able to create dreamy and haunting melodies, as well as simulate a walking bass line as she does in the first song, Autumn Leaves. You’ll notice Pamelia appears to be in a trance while playing the instrument, but as she explains she’s keeping as still as possible so as to not corrupt the tone production. Unintentional body movements or even her breathing can affect the tone she’s trying to produce.

The Bakken Museum of Electricity in Minneapolis has a working theremin on display that visitors can play. Making sounds on the instrument is pretty easy but making music is a completely different story. Like the human voice, the violin, or similar instruments, the theremin allows for what’s called portamento, that is the gliding between a range of tones. You’re not limited by frets or keyboards, and have to sense your way from one note to the other. If you ever get a chance to play an actual theremin you’ll realize just how difficult it is.

Thereminvox.com
Official Pamelia Kurstin website
Pamelia Kurstin on MySpace Music
Some guys performing a theremin jam of Gnarls Barkely's Crazy

Science Friday logo
Science Friday logo
Courtesy Science Friday
It's Friday, so it's time for another Science Friday video... The honk of a horn or the rumble of a truck sounds like noise to most of us. But to Lucy Fitz Gibbon, and others with absolute pitch, there are notes embedded in that noise. Psychiatry professor David Ross, of the Yale School of Medicine, explains what's known about how people acquire this mysterious ability.
Nov
04
2009

Blue, blue, my ears are blue.: The blue morpho butterfly hears through ears on its wings.
Blue, blue, my ears are blue.: The blue morpho butterfly hears through ears on its wings.Courtesy William Warby

The blue morpho does. Scientists have found that this large butterfly of Central and South America has ears on its wings. These primitive ears can distinguish between the high-frequency sound of a bid singing, and the low-frequency sound of a bird flapping its wings. A singing bird is a sitting bird, and thus no threat to the morpho, but a flying bird could be attacking, and detecting those sounds tells the butterfly when to beat a slow, erratic retreat.

(Wait a minute…Blue Morpho…wasn’t he a character in Yellow Submarine Reloaded?)

May
25
2009

Maybe you'll get to like the hum: and maybe not.
Maybe you'll get to like the hum: and maybe not.Courtesy LunaDiRimmel
The hum… if you can’t hear it already, you will now, because now you know about it. And once you hear it, it will never go away. Never.

Before I go any further:
So… I hear that there’s an X-Files episode out there that’s all about this. If this is truly the case, I’d like all of you X-Filiacs reading to just bite down on your autographed Gillian Anderson coasters, and grip your David Duchovny brand Wholesome Stress Release Balls, and just deal with it for a few minutes. (So many people read my posts, I’m sure there must be at least a few thousand die-hard X-Files fans among them.) Are y’all occupied? Think about bees.

Now, for the rest of you (us): The hum.

“The hum” is a sound so low that for most of us it’s usually beyond the southern end of perception. But some people hear it. And they can’t stop hearing it. It’s a deep rumbling tone, and for some people it’s only apparent in certain locations, but to others it can be heard just about everywhere. All the time. The hum has driven people to punch through brick walls, and bite the heads off of gear shifters, because it just won’t stop. (I’m assuming about the brick punching and car biting.)

Scientists believe that the hum is actually a real sound, unlike the tones perceived by people suffering from tinnitus. Tinnitus is an inner ear disorder (and maybe sometimes psychological, which causes people to hear sounds when there’s nothing actually making that sound. The perceived sounds vary, but, in general, it’s like when your ears start ringing for no apparent reason, except that the ringing might never stop.

The hum, on the other hand, is usually perceived as something like the sound of an idling diesel engine. But while there are folks who believe that the hum is actually caused by aliens, and sinister government X-Filesy activity, most scientists believe that the hum is a combination of real sounds (not that aliens wouldn’t make real sounds, but, um…) and a sort of unintended fixation on the part of the hearer.

As this article on the BBC points out, the hum might be caused by the actual vibrations of a nearby factory, or a constantly running piece of equipment in your house, like a fan or the refrigerator. While the sound is so low and quiet that it’s usually barely on the edge of perception, if someone hears it, and focuses on it, they may not be able to make themselves stop hearing it. Once it’s on their minds, they think about how they can’t stop hearing it, and they become focused on the sound, and without intending to they end up adjusting their internal “gain” to notice that sound. Sort of like if you’re trying to be sneaky, the sounds you make seem very loud, or if you’re trying to catch someone else being sneaky, the sound of someone unlocking the front door after curfew is going to be very noticeable.

I just hope none of y’all ever notice the hum. Because what if you can’t stop thinking about it? It’ll always be there… So don’t sit back and try to hear it right now. Don’t even think about that continuous rumbling sound that might be flooding through our town now and forever.

(Oh, if you’re wondering what to listen for, the BBC article has a simulated sample of the hum that you can check out.)

Feb
07
2009

Stradivarious secret is in the sauce
Stradivarious secret is in the sauceCourtesy caribb

Stradivarius violins soaked in "secret sauce"

Having obtained minute wood samples from restorers working on Stradivarius and Guarneri instruments, scientists now have verified that the wood was treated with borax, fluorides, chromium and iron salts. Borax is a wood preservative and an insecticide. It makes sense that wood craftsmen would want to protect their creations from being chewed up by worms.

Joseph Nagyvary, a professor emeritus of biochemistry, first theorized in 1976 that chemicals used on the instruments – not merely the wood and the construction – are responsible for the distinctive sound of these violins." Texas A&M University

Joseph Nagyvary, a professor emeritus of biochemistry, along with Renald Guillemette, director of the electron microprobe laboratory, and Clifford Spiegelman, professor of statistics, all Texas A&M faculty members published their research in the current issue of the scientific journal Public Library of Science (PloSONE).

Learn more about Nagyvary's research

Source: "Secrets Of Stradivarius’ Unique Sound Revealed"
Nagyvary's website: Nagyvary Violins