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Posts tagged with "audio"

Google Explores "Eyes-Free" Phones

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The screens on many mobile phones can leave a user feeling distinctly vision impaired, especially if her attention is divided between tapping virtual buttons and walking or driving. Fortunately, engineers at Google are experimenting with interfaces for Android-powered mobile phones that require no visual attention at all. At Google I/O, the company's annual developer conference held in San Francisco last week, T.V. Raman, a research scientist at Google, demonstrated an adaptive, circular interface for phones that provides audio and tactile feedback.

"We are building a user interface that goes over and beyond the screen," says Raman. Often, eyes-free interfaces are employed for blind users, but Raman, who himself is blind, assures that these interfaces have much broader implications. "This is not just about the blind user," he says. "This is about how to use these devices if you're not in a position to look at the machine."

Source: http://www.technologyreview.com/communications/22731/

Nanotechnology that will rock you

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Forget boxy loudspeakers. Researchers have now found that just a piece of carbon nanotube (CNT) thin film could be a practical magnet-free loudspeaker simply by applying an audio frequency current through it.

These nanotechnology loudspeakers – which are only tens of nanometers thick, transparent, flexible, and stretchable – can be tailored into many shapes and mounted on a variety of insulating surfaces, such as room walls, ceilings, pillars, windows, flags, and clothes without area limitations. The scientists demonstrated that their CNT loudspeakers can generate sound with wide frequency range, high sound pressure level, and low total harmonic distortion.

"Near the end of 2007, we found that just a piece of carbon nanotube thin film could emit loud sound simply by applying an audio frequency current through it" Dr. KaiLi Jiang tells Nanowerk. "But the sound frequency doubles that of the input. We attributed this to the thermoacoustic effect. The alternating current periodically heated the CNT thin films, resulting in a temperature oscillation. The temperature oscillation of thin film excites the pressure oscillation in the surrounding air, resulting in the sound generation."

Source: http://www.nanowerk.com/spotlight/spotid=8007.php
January 2010
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