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Wednesday, June 17, 2009

Indian scientists bridge audio divide

By Raja Murthy

An Indian American duo at the Massachusetts Institute of Technology (MIT) has created new technology based on the greatest engineering feat of nature - the human mind-body structure. Their invention, the Radio Frequency Cochlea, will not only enable a new generation of wireless Internet and communication technologies, but will also serve as a reminder of just how much civilization owes to the inner ear and ancient Asian powers of memory.

Indian American scientists Rahul Sarpeshkar and Soumyajit Mandal have merged human evolution with 21st century technology in their new invention - a high-speed, ultra-broadband, low-power radio chip that works on the same principles as the human inner ear, or cochlea.

Their invention, which they filed for patent as the Radio Frequency Cochlea (RF Cochlea), will usher in the next generation of wireless Internet, cell phone, radio and TV devices, and inevitably impact a US$2 trillion global media and entertainment industry with more advanced sound gizmos.

More immediately, the RF Cochlea will vastly improve radio frequency spectrum in the newly dawning technology of cognitive and smart radios - vital devices that automatically make better use of unused frequencies in our increasingly bandwidth-crowded world.

Sarpeshkar, a well-known professor of electrical engineering at the MIT and his graduate student Mondal, designed the 1mm by 3 mm RF Cochlea chip that is faster and more energy efficient than any currently working in radio-frequency (RF) spectrum analyzers [1].

More significantly, the RF Cochlea opens a fascinating new frontier of technology: living aid devices popping out of science blending with millions of years of human evolution. We could be entering an era of humanology, or more holistic technology uniting two or more disciplines of humanity-related knowledge.

Sarpeshkar told Asia Times Online that his invention has been "enthusiastically" received. "For the first time, we have technology that bridges the working of the human ear with the working of radio," he said.

That professionals involved with hearing having earlier had no working connection with those involved in radio technology sounds incredible. But it demonstrates how obviously related disciplines have been developing on parallel but separate tracks, until Sarpeshkar and his MIT team appeared. More disciplines could similarly and beneficially converge.

Sarpeshkar acknowledged that engineers could learn much from the greatest engineering device known yet to humans: the human mind-body structure.

While Mother Nature's technology is still leagues ahead of the variety created by humans, Sarpeshkar was inspired by nature's design concepts that have evolved over eons.

"Humans have a long way to go before their architectures will successfully compete with those in nature, especially in situations where ultra-energy-efficient or ultra-low-power operations are paramount," he said in a MIT media release dated June 3. "Nevertheless, we can mine the intellectual resources of nature to create devices useful to humans, just as we have mined her physical resources in the past."

Sarpeshkar and Mondal used the same design principles in the human ear to create the RF Cochlea. The device captures radio frequencies a million times higher than the 100 Hz (100 wave cycles per second) to 100,000 Hz that the human ear captures. It includes radio signals for most commercial wireless applications.

In Sarpeshkar's RF Cochlea, human-made inductors imitate the work of fluid mass in the ear, capacitors replicate ear membranes and active radio frequency amplifiers do the work of the outer hair cells in the ear that carry audio as electrical signals to the brain.

"The outer human ear acts as the radio antenna," Sarpeshkar explained to Asia Times Online, "the middle ear sifts through the substance from unwanted noise and the inner ear, or cochlea, is the amplifier and separates frequencies before sending signals to the brain."

As Sarpeshkar pointed out, RF Cochlea represents not merely a more holistic blending of human technology with nature's engineering, of merging biology with advanced electronics, but it also gives insights about the sense of hearing, a faculty fundamental to the development of civilizations.

That the inner ear and the evolving human mind are inter-dependent is obvious with the ancient world's richest treasures of wisdom first preserved and passed on across millennia through the inner cochlea hearing the spoken word, not eyes reading written script, and storing those words accurately in powerful memory.

The sensory impact the inner ear has on the mind becomes evident in how great oratory mesmerizes more than a great essay, or the way great music captivates and changes moods more than great prose. In his famous dialogues of Phaedrus (360 BC), ancient Greek teacher Plato too argues of the superiority of the spoken over the written word.

Sarpeshkar's South Asian origin fits with the ancient regional tradition of the heard and memorized word, via the inner cochlea, protecting old world knowledge and wisdom from invading culture destroyers burning libraries, books and manuscripts. The connection between the inner ear and memory can make fascinating scientific study.

"While the textual riches of Alexandria, China and Rome were being put to the flame, a wholly different tradition of scientific expression was brought to a peak in India, in a manner that would prove enormously more resilient to the vicissitudes of time and adversity," observed Alok Kumar, Department of Physics, State University of New York. "This was the oral, poetic tradition of Indian thought, whose greatest purveyor in astronomy and mathematics was Aryabhata."

Mathematician astronomer Aryabhata (born 476 AD), after whom India named its first satellite launched in April 19, 1975, composed the Aryabhatiya, a remarkable astronomy and mathematical work in poetic form. "There are no numbers anywhere in Aryabhata's composition in Sanskrit language, nor are there figures, drawings, or equations," wrote Kumar in his project note for the New Jersey, Princeton-based Educational Council on Indic Traditions organization that commissioned him to study ancient Indian contributions to science. "The Aryabhatiya expresses the highly sophisticated mathematics of sine functions, volumetric determinations, calculation of celestial latitudes and motions, and much more, in the form of a poetic code."

Inputs through the inner cochlea and advanced powers of memory preserved a more priceless treasure, the Buddha's teaching of Dhamma, or universal laws of nature, that detailed a non-sectarian path for freedom from all suffering - by objectively observing the constantly changing mind-matter phenomena within, manifesting at the bio-chemical level as bodily sensations arising and passing away, instead of blindly reacting to whatever we experience in the outside world.

The entire 82,000 discourses of the Buddha and related commentaries in Pali, one of the oldest known languages, were memorized and their authenticity confirmed in historic congregations of monks such as the Chatta Sanghayana or Sixth Council held in Yangon, Burma, between 1954 and 1956.

The First Council was convened in 544 BC, in the Sattapaaai Cave located outside Rajagaha, northern India, three months after the Buddha passed away. It was only during the Fourth Council held in Tambapanni, Sri Lanka, in 29 BC under King Vattagamani's patronage, that the voluminous Tipitaka [2] texts containing the Buddha’s teachings and related commentaries were committed to written script on palm leaves.

In the Chatta Sanghayana or Sixth Council in Burma, 2,500 learned monks from Myanmar, Cambodia, India, Laos, Nepal, Sri Lanka, Thailand and Vietnam recited the entire 82,000 discourses and related commentaries that they had heard and committed to memory, as did generations of monks across two millennia.

"An European spectator would have marveled at this preternatural feat, but it [extraordinary powers of memory of the heard word] is a commonplace occurrence in this area of the world," wrote a leading Sri Lankan scholar Harischandra Kaviratna in his 1971 essay "Unbroken Chain of Oral Tradition".

Sarpeshkar's RF Cochlea marks the latest milestone in the evolutionary journey of human hearing and civilization, a path that transcends a distance from 544 BC when the Buddha's personal attendant Ananda narrated to the First Council the entire discourses he heard from the Buddha, word for word. Ananda started every repeated discourse with the words in Pali "evam me suttam", meaning "Thus, have I heard [from the Enlightened One]".

"As in all interdisciplinary fields, it is important to synergistically combine the creativity and excitement generated by new non-traditional thinking with the discipline and knowledge of older ideas," said Sarpeshkar who calls the biological inner ear an "amazing custom analog computer".

"The cochlea quickly gets the big picture of what's going on in the sound spectrum," said Sarpeshkar. "The more I started to look at the ear, the more I realized it's like a super-radio with 3,500 parallel channels."

Forty-year-old Sarpeshkar was born and brought up in Bangalore before he left for the US as an under-graduate student. He holds over 20 patents, has authored more than 70 publications and ranks among the world's most brilliant young scientists from South Asia. His several awards include the Packard Fellow award, given to outstanding young faculty, and the Indus Technovator Award, which MIT instituted in 2003, for distinguished young innovators of South Asian origin working at the confluence of technology research and entrepreneurship.

After obtaining his degree in Electrical Engineering and Physics at MIT and his PhD at Caltech, Sarpeshkar joined the technical staff at Bell Labs, Biological Computation department within its physics division. Since 1999, he has served in MIT's Electrical Engineering and Computer Science Faculty, leading a research group on analog VLSI and biological systems that works on developing what it calls "low-power brain-machine interfaces".

The cosmopolitan Analog VLSI MIT team reflects the kind of international talent that MIT hopes to nurture in country specific programs it has operated since 1994 in China, Japan, Israel, India, France, Germany, Italy, Mexico and Spain.

Sarpeshkar's MIT team, for instance, includes Scott Arfin, Benjamin Rapoport, Lorenzo Turicchia, Micah O'Halloran from the US; Serhii M. Zhak from the Moscow Institute of Physics and Technology, Russia; Soumyajit Mandal from the Indian Institute of Technology, Kharagpur, Keng-Hoong Wee from Tohoku University, Japan; and Woradorn Wattanapanitch from Thailand.

So far, their brain-machine interfaces work to combine the human physical structure and 21st century technology has produced:

A new generation of high performance, low-power devices that mimic the communicating relationship of the mind, brain and human limbs, to help paralysis patients, the blind, and victims of Parkinson's disease and epilepsy. These ultra-low power brain-machine devices can run for 10 years or more, compared to current bulky devices that are 100-10,000 times more power and often lack wireless capabilities.

The Bionic Ear project to design advanced ultra-low-power cochlear-implant systems that also enable the deaf to hear music and tonal languages such as Chinese and other East Asian languages. Tonal languages use variations in tone, or pitch, to express different meanings of words. For example, the Mandarin word "ba" can be used with four different intonations to mean "eight", "to uproot", "to hold" and "a harrow". In contrast, English is a stress or accent-oriented language.

"Biological systems have developed over hundreds of millions of years of evolution to perform sensory, motor and chemical tasks extremely efficiently and robustly while using very little power, in very little volumes, and in real time," said Sarpeshkar, who sees his research as just the beginning of a journey for many more efficient, adaptable and cost-effective technologies to be developed from biology.

The RF Cochlea device demonstrates what can happen when researchers take inspiration from fields outside their own, said Sarpeshkar. "Healthcare is a natural area for applying biologically inspired technologies since we are trying to engineer systems that perform the normal functions of biological ones, so mimicking the biology can be helpful in fixing it."

Sarpeshkar's work also reflects the rewards that come by way of those daring to walk the rarely trodden path. "I have followed my heart in my work, and in my love for science," he said.
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