Brazilian Bus Magnate Is Buying Up All the World’s Vinyl Records

Paul Mawhinney, a former music-store owner in Pittsburgh, spent more than 40 years amassing a collection of some three million LPs and 45s, many of them bargain-bin rejects that had been thoroughly forgotten. The world’s indifference, he believed, made even the most neglected records precious: music that hadn’t been transferred to digital files would vanish forever unless someone bought his collection and preserved it.

Mawhinney spent about two decades trying to find someone who agreed. He struck a deal for $28.5 million in the late 1990s with the Internet retailer CDNow, he says, but the sale of his collection fell through when the dot-com bubble started to quiver. He contacted the Library of Congress, but negotiations fizzled. In 2008 he auctioned the collection on eBay for $3,002,150, but the winning bidder turned out to be an unsuspecting Irishman who said his account had been hacked….

Read the full story here

Source: New York Times

Extracting audio from visual information

Algorithm recovers speech from the vibrations of a potato-chip bag filmed through soundproof glass.

Researchers at MIT, Microsoft, and Adobe have developed an algorithm that can reconstruct an audio signal by analysing minute vibrations of objects depicted in video. In one set of experiments, they were able to recover intelligible speech from the vibrations of a potato-chip bag photographed from 15 feet away through soundproof glass.

In other experiments, they extracted useful audio signals from videos of aluminium foil, the surface of a glass of water, and even the leaves of a potted plant. The researchers will present their findings in a paper at this year’s Siggraph, the premier computer graphics conference.

“When sound hits an object, it causes the object to vibrate,” says Abe Davis, a graduate student in electrical engineering and computer science at MIT and first author on the new paper. “The motion of this vibration creates a very subtle visual signal that’s usually invisible to the naked eye. People didn’t realize that this information was there.”

Read the full story here

Source: News Office – MIT

Acoustic Scientists Find Longest Ever Echo

Deep inside a complex of secret tunnels in the Highlands stirs a sound which will reverberate through the ages. The world record for the longest echo ever discovered has been shattered by a hidden network of oil storage tanks in Rossshire.

Inchindown oil storage tank

Acoustic scientists emerged from the Inchindown oil storage tanks, an underground fuel depot constructed during World War II, with proof that a gun-shot fired inside the tunnel resonates for a full 112 seconds.

The discovery marks a resounding defeat for the previous record-holder for the longest echo found in a man-made structure, the Hamilton Mausoleum, also in Scotland, where the sound of the doors being slammed shut took 15 seconds to die away to silence.

Guinness World Records has certified the findings made by Trevor Cox, Professor of Acoustic Engineering at the University of Salford and author of Sonic Wonderland: A Scientific Odyssey of Sound.

Prof Cox had received a tip that the Inchindown complex near Invergordon might prove fertile territory for an echo test.

Excavated out of solid rock between 1939 and 1941, the tanks were dug deep into the hillside amid concerns about the strengthening of Germany’s armed forces and the threat posed by long-range bombers.

The tunnels were to provide a huge bomb-proof reserve supply of furnace oil for the warships of the home fleet at Invergordon, a key Royal Navy anchorage.

Prof Cox had to enter the tank through one of the 18 inch diameter oil pipes because there are no doors. The tank was designed to hold 25.5 million litres of fuel and has walls 45 cm thick. The space is about twice the length of a football pitch, 9m wide and 13.5 metres high.

Allan Kilpatrick, an archaeological investigator for the Royal Commission on the Ancient and Historical Monuments of Scotland, fired a pistol loaded with blanks about a third of the way into the storage tank. The results stunned Prof Cox, who recorded the response picked up by the microphones about a third of the way from the far end.

“It was like going underground into a Bond villain’s lair. But never before had I heard such a rush of echoes and reverberation,” Prof Cox said. “I started off just playing around, whooping and hollering. The sound just goes on and on and on.”

“Then when we fired the pistol my initial reaction was disbelief; the reverberation times were just too long. I knew immediately we had a new world record.”

Read the full story here.

Source & image: The Independant

Sonic Warfare

The power of sound

Sound is an amazing force, and one that is often overlooked in terms of its powerful influence and destructive potential. The lucky ones among us get to hear sound every day, and what a privilege it is. There are times, however, when hearing may be a detriment to us. This is increasingly becoming the case with the development and application of sonic weapons by various military forces. Sound as a weapon is not a particularly new idea, but for years there has been much secrecy and misinformation shrouding the subject.

“Possibly the first mention of sonic warfare is the now much-cited ‘Walls of Jericho’ scenario — a biblical story which no doubt many of us are familiar with. The walls came tumbling down after the synchronised blast of trumpets and voices rendered it unstable. However, it is only recently that sound has seriously been considered as a valid medium for destruction. Human beings respond to certain categories of sound in a number of complex ways involving auditory perception and psycho-physiological response mechanisms rendered through the brain. Certain species of sound above (ultrasound) or below (infra-sound) the levels of human auditory perception would theoretically prove most effective within the crucible of warfare.”Spannered

What can sound do that is so damaging? Well, this is a broad question and is best answered by saying that it depends on the frequency, amplitude and medium of the sound wave. For instance, have you ever heard of the opera singer, Caruso, who could shatter a crystal glass with the power of their voice alone? It is entirely possible to shatter glass with sound. It is simply a case of hitting a note that resonates sympathetically with the glass.

Shattering glass

Along the same lines as the opera singer and the glass is another example of acoustic damage, a pretty extreme one actually. The human heart is, like everything, not indestructible. However, I bet you never thought you could stop a human heart with sound waves alone? Well, you can. Again, it wouldn’t be easy, but the science suggests it could be done. All that is required is a frequency that resonated with the heart significantly enough to actually stop it from beating. Imagine that…the potential to kill someone without touching them, poisoning them, shooting them or leaving a shred of evidence such as DNA on the crime scene. All that is essentially needed is a signal, an amp and a speaker, though this is a simplification!

“A variety of nonlethal acoustical weapons have been proposed and evaluated. Some of these are little more than fancy loud-speakers, while others involve more subtle or sophisticated processes and truely deserve the designation of acoustic weapon.”Global Security

It is also possible to raze buildings with sound alone. Low frequency waves would be best ‘weapon of choice’ as they have a long wavelength and are able to vibrate a wall or structure quickly enough to cause degradation to the structural integrity of the building. The frequency of the tones would need to be very low, lower than can be heard by humans (below 20Hz). Sound below this threshold is known as infra-sound and it’s effects are felt but not heard. You would need a huge amount of amplification to achieve the destruction of a building in this way, but the fact that it is possible is amazing.

“Infra-sound would be a powerful ultra-low frequency (ULF) weapon that could be directional and tunable, penetrating buildings and vehicles. High Intensity infra-sound could induce disorientation and reduced sensory motor functions. At higher levels of intensity, experimental have shown that animals may cease breathing temporarily. But this has seemed to be not a very practical weapon, since large banks of speakers were required to provide directionality, and power demands were deemed excessive.”Global Security

In other settings you may not wish to destroy a building, you may instead want to remove certain people from a building through relatively passive means, and sound can get the job done! An example of this was seen in 1990 when American forces attempted to drive Manual Norriega, military dictator of Panama from 1983-89, a from the Vatican Embassy in Panama in 1990 using sound. The US military played loud rock music such as Van Halen – Panama, and I fought the Law, by the Clash. Through continuous playback over many hours the US managed to psychologically wear-down the former dictator, resulting in his surrender. This method was preferable to brute force, as Norriega was holed up in the Vatican Embassy, and if US troops were to set foot in the Embassy they would anger many Catholics worldwide. In such a setting sound was the ideal solution to the problem at-hand.

Manuel Noriega

Manuel Noriega

Another example of the destructive capability of sound is feedback. This is a closed system where sound grows exponentially with every cycle of its loop. A classic, if not tired, example of this is the rock gig scenario. We’ve all heard the shrill shriek of feedback once or twice at least, and it’s not pleasant.

How is it caused? It’s really very simple. Sound waves from a vocalist, for example, are picked up by a microphone, which is connected to an amplifier. Amplification of the signal occurs and the sound is output through a speaker. If conditions are correct (or incorrect from a sound engineers point-of-view), sound will travel from the speaker and back into the microphone, this is the beginning of another loop. If sound repeats this loop too many times then audible feedback will arise, growing into a deafening howl. Literally. While the effects of a single exposure to feedback are likely to be minor to insignificant, if the exposure is significant enough then damage to the ear system could occur. Indeed, if you have ever suffered from ringing ears after exposure to high amplitude sounds then the chances are that you have suffered permanent hearing damage.

A diagram illustrating a feedback loop

A diagram illustrating a feedback loop

If going to a rock gig with the intention of listening to the band – not being deafened by them – can cause permanent hearing loss to the majority of the audience, then imagine how damaging sound can be to us when we try to make it damaging!

LRAD, the Long Range Acoustic Device, is a new technology used to control crowds, deter pirates or insurgents from cruise or cargo ships. It has, allegedly, only been used a couple of times in a real-life setting, so accurate information on its effect is sparse. According to the manufacturers specification:

“The equipment weighs 45 pounds (20 kg) and can emit sound in a 30° beam (only at high frequency, 2.5 kHz) from a device 83 centimetres (33 in) in diameter. At maximum level, it can emit a warning tone that is 146 dB SPL (1,000 W/m2) at 1 metre, a level that is capable of permanently damaging hearing, and higher than the normal human threshold of pain (120–140 dB). The maximum usable design range extends to 300 metres. At 300 metres, the warning tone (measured) is less than 90 dB. The warning tone is a high-pitched shrill tone similar to that of a smoke detector.”LRAD Corporation

LRAD X1000

LRAD X1000

The LRAD was first used on US citizens at the G20 protests. As you can see from the video it certainly gets people moving when it is switched on. If you are going to watch this video, turn your volume down first – it is very loud!

“In the early 1970’s, acoustic engineer Vladimir Gavreau was experimenting with infra-sound weaponry. Now the stuff of infra-sound legend, Gavreau was responsible for the construction of a giant 6ft whistle, powered by compressed air, which reputedly scrambled the inner organs of it’s unfortunate operator (a phenomenon known as ‘cavitation’, where the internal physiology was fatally resonated). Distraught, Gavreau ceased his experiments, but left behind plans and models for highly sophisticated, directional sound cannons, which were apparently seized by the French authorities. In a recent conference with Dr Guy Peter Manners, Professor of Cymatics (a form of sonic therapy)….he informed me of experiments which he had first hand experience of in wartime Germany, where sonic weapons were being developed under a highly classified strategy initiated and financed by Hitler’s government. …A separate source reveals the fact that the Germans were pioneering a sound-based weapon known as the ‘Luftkanone’, developed at Talstation Lofer. This was a parabolic device which, although untested on humans, was apparently… ‘capable of killing a man with sound pressure in about 30-40 seconds. At greater ranges, although not lethal it would be able to disable a man for an appreciable length of time. Vision would be affected, and low-level exposure would cause point sources of light to appear as lines.'”Spannered

Acoustic devices being used as weapons doesn’t sound all that strange, not when you consider that the US military is behind it. They have a high military spending budget and view themselves as being the police force of the world. To me, an interesting question was “do acoustic weapons appear anywhere in nature? If so, why what, and what are the effects?”

After doing a small amount of research I discovered the amazing Pistol Shrimp. This little creature is capable of disrupting submarine communications with the sound of it’s pincers alone. They make a loud ‘chattering’ noise as they close the pincers, which carries a long way in water due to the density of the molecules (the speed of sound in wate is close to 1,500 metres per second, but it is temperature dependant). The really amazing part of the story about Pistol Shrimps is their ability to stun other sea creatures by snapping their pincers together extremely quickly. This creates a blast of bubbles which momentarily heats up to approximately 6,000 degrees Celsius (the same temperature as the surface of our Sun). The attacked creature is immediately stunned and is paralyzed, leaving the shrimp to clear up without a fight! It is incredible. You can really see why they have been given there name when you watch them using this incredible ability of theirs. Here is a video I found of the Pistol Shrimp in all its glory.

So, we have now seen acoustic weapons as used by Humans, and animals alike. Is there an application of sound that combines both animals and Humans? Yes, there is.

Pine Beetle

Pine Beetle

In Canada and North America the Bark Beetles population was growing rapidly and they little critters were destroying up to 33 million acres of forest in British Columbia and millions more in the United States. Scientists discovered that if they recorded the ‘song’ of the Bark Beetles, modified them slightly and played back the recording to the beetles they got instant and unexpected results. Hofstetter, one for the scientists involved in the research, explains.

“We could use a particular aggression call that would make the beetles move away from the sound as if they were avoiding another beetle. Or we could make our beetle sounds louder and stronger than that of a male beetle calling to a female, which would make the female beetle reject the male and go toward our speaker. We found we could disrupt mating, tunneling, and reproduction. We could even make the beetles turn on each other, which normally they would not do.” – Hofstetter

Using this technique they scientists were able to drive the beetles away from the trees and thus saving them from destruction.

As you can see, sound is very powerful and has many applications beyond the obvious ones such as listening to music and communicating ideas, etc.

Sound for Surgery

SurgeonsIn my youth I discovered some of the less obvious applications of sound, and this was part of my attraction to the field of audio studies. Suddenly sound wasn’t just a result of striking two things together, for example. It wasn’t just music or communication – I had learnt that sound waves had the potential to do so much more, and I liked it!

Take brain surgery for example. The tool that would come to mind for most of us when we think about surgery is probably a scalpel, or possibly a saw of sorts (sorry, I know that creates some vivid and rather unpleasant imagery, but I’m trying to make a point here).

Well, this could all change thanks to sound waves. A revolutionary new approach to neurosurgery avoids both radiation and a scalpel.

The new ultrasound device, used in conjunction with magnetic resonance imaging (MRI), allows neurosurgeons to precisely burn out small pieces of malfunctioning brain tissue without cutting the skin or opening the skull.

A preliminary study from Switzerland involving nine patients with chronic pain shows that the technology can be used safely in humans. The researchers now aim to test it in patients with other disorders, such as Parkinson’s disease.

The surgery is done using ultrasound waves – simple sound waves that are higher in frequency then the human hearing range – concentrated so much that they can heat up cells until they die.

To do this the sound waves are focussed to a single point, just like using a magnifying glass to concentrate light beams on a point where they can burn. This concentrated point can be less than a millimetre in diameter, and the surgeons can position it with extreme accuracy using an MRI scanner to guide the beam.

The focussed ultrasound technique is already being used to treat conditions such as uterine fibroids in the UK. However, the major challenge in using ultrasound in the brain is figuring out how to focus the beams through the skull, which absorbs energy from the sound waves and distorts their path. InSightec, an ultrasound technology company headquartered in Israel, has developed an experimental HIFU (High-intensity focused ultrasound) device designed to target the brain.

The InSightec device consists of an array of more than 1,000 ultrasound transducers, each of which can be individually focused. “You take a CT scan of the patient’s head and tailor the acoustic beam to focus through the skull,” says Eyal Zadicario, head of InSightec’s neurology program. The device also has a built-in cooling system to prevent the skull from overheating!

To read more on the topic, check out the links below.

I have actually written another article for another site which focusses on sound being used in an altogether different application, so perhaps I’ll grab that and post it on the Band Mate blog sometime soon. Keep an eye out.

Sources: BBC, MIT Technology Review, InMotion

Band Mate is One Year Old!

Band Mate's one year birthday!

Band Mate’s one year birthday!

Today marks the one year anniversary of the Band Mate site-launch! I am very pleased that the site is still running and gathering users. I am also very grateful to everyone that has signed up, created musician ads or shared the site with friends during the last year.

I accept that the site is still small in terms of the number of users. When I embarked on building Band Mate I certainly envisaged the site gaining more users within it’s first year, but the internet is a ruthless place, and I set no advertising budget for the Band Mate site. As such, the site has grown exclusively through ranking in search engines, as well as my occasional tweets reminding people that the site is out there, ready and waiting.

When a site of this nature launches, there is little to attract the initial visitors to the site. They see a musician-finder with little to no musicians listed on it. Why sign up? Yet it is only through people taking that step to sign up that there will ever be scores of musicians listed on the site. It is for this reason that I appreciate those who have taken the time to sign-up so much. They made the effort and showed their support for a young site like Band Mate.

Thanks again to everyone who has used Band Mate. Kudos to you. Here’s to more years on the internet, more users signing up, and more bands forming as a result of the former two points!

Record grooves under an electron microscope

Chris Supranowitz is a researcher at The Insitute of Optics at the University of Rochester. Along with a number of other spectacular studies (such as quantum optics, trapping of atoms, dark states and entanglement), Chris has decided to look at the grooves of a vinyl record using the institutes electron microscope.

The process of capturing the images is not as simple as just sticking a record under an expensive microscope, there is a lot of preparation (such as gold-sputtering the surface) and post-processing to be done.

Vinyl grooves 1

The dark bits are the top of the grooves, i.e. the uncut vinyl


Vinyl grooves 2

The grooves even closer up – the little bumps are dust on the record

Vinyl grooves 3

A single groove magnified 1000 times

CD pits

Chris also imaged the pits in a CD – here’s what they look like, just for contrast

3D image of vinyl grooves

Chris created a blue/red 3-dimensional image of the record groove! If you have a pair of 3D glasses (anaglyph), pop them on and take a look at this!

Source: SynthGear

Infinite Descent: Shepard Tones

Shepard Tone in spectrum view

Shepard Tone in spectrum view

Can you imagine hearing a tone that sounds as if it is constantly ascending or descending in pitch, yet which ultimately seems to get no higher or lower? It sounds like some kind of sorcery, but it is a fairly simple auditory illusion. A trick played on the mind. The tone in question is called a Shepard Tone.

Before I go on to explain how such a tone is constructed, you may wish to hear an example of this sorcery. You can hear it for yourself in this video which combines the Shepard Tone with fractals – a fascinating topic in their own right.To prove a point that the tone never does get any lower in pitch, the creator of the video made it 10 hours long! Watch the whole thing if you want, but I think you might be in some odd trance but the time it finishes.

So how is such a tone created? The basic concept is that there are a series of overlapping sine waves that start at a given pitch, and glissando down to the same pitch one octave lower/higher. For the purposes of this post we will assume we are dealing with a downward glissando. Here is an except from Audiotuts+ which explains the concept well.

You start with a Sine wave say on note A4 which sits at 440 Hz and you have it glissando down to A3 at 220 Hz over a period of time. During the same time you have another glissando starting on A5 at 880 Hz and dropping down to 440 Hz.

If you were to repeat this cycle the glissando starting on 440 Hz would pick up where the glissando starting on 880 Hz left off. This creates the continued sensation of a falling pitch. However, if you repeat the cycle then you will quickly jump back to 880 Hz and will noticably hear it. So what do we do? In order to achieve a smooth and seemingly endless cycle we need to fade in the upper most glissando and fade out the lower most.

Through the use of fades we can create a seamless join and the effect is an infinitely decending tone. Really quite cool, wouldn’t you say?

Read the full article from Audiotuts+.

The World’s Ugliest Music

Scott Rickard at TEDx

Scott Rickard at TEDx

You could be mistaken for thinking that this post will be about Justin Beiber or some other ‘musician’ of that calibur, but no — this music actually requires talent!

Scott Rickard set out to do what no musician has ever tried — to make the world’s ugliest piece of music. At TEDxMIA, he discusses the math and science behind creating a piece of music devoid of any pattern.

Scott Rickard has degrees in Mathematics, Computer Science, and Electrical Engineering from MIT and MA and PhD degrees in Applied and Computational Mathematics from Princeton University. At University College Dublin, he founded the Complex & Adaptive Systems Laboratory, where biologists, geologists, mathematicians, computer scientists, social scientists and economists work on problems which matter to people. He is passionate about mathematics, music and educating the next generation of scientists and mathematicians.

Have a look at the video here.

As Rickard says: Try and find any enjoyable aspect of this music, and then revel in the fact that you cannot!