Acoustics & Audio Technology News

Scientists from Duke University have demonstrated a cloaking technique to make objects invisible to sound waves. But unlike the unique metamaterials needed to make objects invisible to light waves, arrays of holes in stacked plastic sheets make ships invisible to sonar. In air, this acoustic cloaking approach is functional for the 1 to 4 KHz range of audible frequencies. Size and location of the holes, plus the spacing between the plastic sheets, influence how incoming sound waves are affected. Not surprisingly, the same technology could be applied to optimize the acoustic design of concert halls.

TES Electrical Electronic Corp. is a professional test instrument manufacturer dedicated to all kinds of handheld equipment. The TES-1354/1355 Noise Dose Meter measures: personal sound exposure measurement at work, percent noise dose, exposure time, sound level, and more. Find out more about TES Electrical Electronic Corp.

The OROS Overall Acoustic is an optional NVGate plug-in for all OROS 3-Series Analyzers. With an OROS 3-Series you get a multi-channel analyzer, so why not turn your unit into a true multi-channel sound level meter. The OVA plug-in extends the analyzer capabilities to a comprehensive acoustic measurement system.

With the explosion of portable electronic devices that feature built-in miniature speakers, manufacturers face the challenge of making them louder while delivering higher quality sound as educated consumers now demand. Fortunately, all kinds of design nuances and processing techniques can be implemented to make these size-constrained speakers perform like much bigger counterparts, as this EE Times article describes.

Debuting at the Consumer Electronics Association show, a wireless system combines a high-fidelity speaker with a 10 W LED light. A MusicLite unit comprises a 70 mm full range loudspeaker, a 65 W reflector bulb equivalent LED — plus a remote to control both — and a wireless audio receiver. Completing the package, a 2.4 GHz wireless transmitter connects to practically any audio source.

Positioned between an electronic device being charged and a power source, a metamaterial could facilitate wireless power transmission. Functioning as a lens, the material controls the waves, making it seem like there's no gap between the device and the power source. Resembling a Venetian blind, the hypothetical metamaterial would be an array of thin conducting loops of PCB copper-fiberglass material.

To overcome the problem of traditional underwater microphones becoming less sensitive with depth, researchers developed a new hydrophone modeled after an orca ear. The diaphragm of the device consists of a plastic-membrane-covered silicon chip, but the membrane is 25x thinner than regular plastic film. Water flows in and out through a network of nanoholes, solving the depth sensitivity problem.

Extech sound meters, from Fotronic Corporation, include all the features and functions needed for basic noise level surveys or to meet the requirements for OSHA compliance, community noise ordinances, or machine noise evaluation. It is tripod mountable and has a ±2 dB accuracy with 0.1 dB resolution.

The new Larson Davis Model 831 Sound Level Meter Reverberation firmware was designed to comply with the latest ISO 3382-2 and ASTM E2235-04 measurement standards. It supports both the Integrated Impulse Response and Interrupted Noise excitation methods and includes an automated trigger to easily control the measurement.

Near the beginning of the Iraq war, radio-frequency (RF) jammers were top secret — reporters mentioning such equipment were sent home. Still today, the "battle for the electromagnetic spectrum" continues to be fought worldwide, but the technology is advancing. Characterized as "uber jammers," 20,000 units of ITT's JCREW 3.3 machines will be built if the equipment passes muster, as Wired.com reports.

In the near future, Volkswagen drivers will be able to drive virtually hands-free while monitoring a new control system with an electronic horizon. Featuring radar, a camera, laser scanner, ultrasonic sensors, and more, a new "Temporary Autopilot" (TAP) semi-automatically controls Volkswagens up to 80 mph. Vs completely automatic technologies, TAP uses a "production-like sensor platform."

Continuous blood-pressure monitoring can now be done more easily with a new wireless monitor. The wristwatch-like monitor has functional software to keep both doctors and patients informed of critical vital signs — sounding an alarm for abnormalities. In use, data is transmitted to a pateint's cellphone and then onto the cloud for medical professionals to check a 24 hour graph of the results.

Designed to work with any Bluetooth 4.0 compatible smartphone or other gadget, a heart rate chest monitor can be set up in mere seconds. Measuring 3.8 x 6.5 cm, the 1.1 cm thick monitor unit is encased in plastic and resides in a soft fabric belt. Weight is only 46 g or less than that of two AA batteries. Based on running 1 hr/day, the device will run for 18 months when powered by a CR2032 button cell.

BK Precision 735 Sound Level Meter, Digital, Datalogging, with RS-232 software and cable.

Whether you are testing for OSHA compliance, quieting equipment, or monitoring the roar of a stadium crowd, B+K Precision's Sound Level Meters can get the job done. With the model 735, BK Precision can meet all your sound testing needs.

Densitron Corporation breaks the 6 in. touch screen barrier with the introduction of their 5.7 in. Surface Acoustic Wave (SAW) Touch Screen into North American Markets. Industries such as medical equipment and industrial instrument manufactures are looking toward touch screens to enhance the user experience of their products.

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U.S. researchers have come up with a way to allow astronauts to perform ultrasound exams in space to replace an onboard doctor plus CAT scans or MRI testing. The resulting "ultrasound intuitive guide" lets astronauts conduct exams on the International Space Station. Astronauts can now diagnose collapsed lungs, fractured bones, kidney stones, organ damage, and more using a catalog of images.

To date, augmented reality hasn't really taken hold except for a few impressive smartphone apps. But thanks to Sony's new augmented reality system, that scenario is changing. Utilizing Smart AR in mobile gaming, for instance, allows real-world objects to participate in the game. Here, game characters materialize on a tabletop, for example, and respond to moving real objects. See it, to believe it.

Do You Safeguard Your Hearing?

Loud noises at both work and play can permanently affect your hearing. What precautions do you take?

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