Acoustics & Audio Technology News

Audio headsets — Bluetooth especially — do make life easier for multitasking. But in operation, talk times and standby times are often not quite what the user expects. The solution for some may be a $99 solar-powered headset (chargeable indoors or outdoors) to attain up to 12 hr talk times. In contrast, gamers may want to invest their tech dollars in a $299 neuroheadset due out later this year.

High linearity and optimal efficiency in RF amplifiers for cell phones, base stations, and other electronics are not necessarily mutually exclusive as long as "clever techniques" are used in the design according to a recent EDN article. In handsets, higher efficiency corresponds to longer talk time or battery life; in base stations, less power consumed and lower heat equates to lower overall costs including electric bills.

Just proven recently, the antlers on a bull moose actually perform an acoustic function. When sound waves bounce off the wide palms of the antlers, the moose turns his ears toward them. This amplifies the sound by almost 20%. Researchers believe it's the only land mammal possessing such a built-in amplifier. Incidentally, a moose's ear is 60x larger than a human's.

Keeping boisterous highway noise at bay was previously accomplished by erecting a giant wall of concrete, wood, or composite to block it out. Not surprisingly, there are always better alternatives. A case in point is using 0.5 in. thick acrylic sheet as a sound blocker. One recent installation in Orange County, CA runs 1500 ft in length providing 8 to 12 dBA noise reduction while providing 92% light transmission, an important aesthetic benefit for residents.

Today, going greener by saving energy is a primary goal when controlling industrial motors, solar and wind power equipment, CNC machines, and more. One way to accomplish this in increasingly complex embedded systems is to utilize floating-point digital signal controllers (DSCs) with SoC integration. This approach delivers a bevy of benefits vs a fixed-point alternative beyond now being more affordable.

Depending on the reference, there is no definitive answer as to whether test-and-measurement instruments should be external or on-chip. Fortunately, Rick Nelson, EDN editor-in-chief, tackles the issue, providing an up-to-date perspective, current trends, and references in his recent editorial. Although more cost-effective testing than million-dollar systems is needed, he predicts that embedded instruments won't replace external counterparts.

Mobile phones in the near future will attain data rates of 250 Mb/s on the downlink. Scheduled to report on extensive test results shortly, the Japanese service provider is targeting 2010 for the first rollout. In the longer term, the company plans to incorporate small biochips or biochemical analyzers to send medical data wirelessly to health specialists.

With a plethora of Bluetooth devices all the rage today, it peaks one's curiosity to find out why and how this wireless communication protocol got this definitely unique name. Way back in 1996, a special interest group (SIG) seeking to define short-range wireless needed a codename for the developing technology. To make a long story short, Bluetooth's roots trace back to King Harald Bluetooth who united Denmark in the 10th century, just like the SIG was attempting to unite members 1,000 years later with a single wireless standard.

World's Earliest Voice Recording

As it turns out, history stands corrected. Thomas Edison take note. The oldest voice recording to date was made in 1860 (perhaps 1853) by a Parisian who created a 10 sec recording of Au Clair de la Lune with his phonautograph. The inventor, Édouard-Léon Scott de Martinville, made his recordings on blackened paper using a horn-stylus contraption. Timeline-wise, Edison's Mary Had a Little Lamb came about two decades later.

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The Paradoxical Search for More "Juice"

Sooner or later, virtually all users of cell phones and other electronic mobile devices run into a compromising situation when batteries go dead. What do you think OEMs should do to solve the problem?