Holosonics is selling the “audio spotlight”, an ultra-sonic loudspeaker than generates audible noise by the non-linear behaviour of air. The radiation pattern is a few degrees, so that sound does not disperse like a conventional loudspeaker. A special signal processing amplifier is required to convert audible signals into the ultra-sonic range.
Read more on the Holosonics web site.
With the investment of ESI Group into Vibro-acoustic Sciences, the makers of AutoSEA and other software products, the company has been split into two groups. The sales office in San Diego and Detroit are now called ESI North America. Vibro-Acoustic Sciences now only exists in San Diego and is a research and develop company, working on improving AutoSEA and continuing to develop the Resound software.
Read the press release on the ESI Group web site.
JMC Products has developed a DC motor for fans that is significantly quieter than conventional motors. In a conventional fan motor a square wave switching voltage is applied to the stator that generates torque ripples and vibrates the entire structure which makes a ticking noise. JMC have reduced this noise by changing the switching frequency to 25kHz, above the range of human hearing.
Read the JMC media release here.
Alpine, a Japanese manufacturer of audio, video and security products for cars, has developed a car audio system called the Alpine F1 Status. Each time the system is switched on, the acoustic characteristics of the cabin are analyzed using a Time Stretched Pulse technique to synchronize the arrival time of sound from the speakers in the car.
Read more on the Alpine web site.
Matsushita, the Japanese company that manufactures under the Panasonic and National brands, have developed a technique to provide a listener wearing headphones the feeling of 3-dimensional sound. Typically people wearing headphones think the noise is coming from the center of their head. The new technique involves modifying the sound to account for the transfer function of the ear canal, so that the listener thinks the sound is coming from in front.
Read the press release on the Matsushita web site.
Panasonic make a range on noise cancellation headphones and earphones. See the Panasonic web site for more details.
David Swanson from Penn State University has developed a security system called APIDS – acoustic perimeter intrusion detection system. The system uses wires connected to geophones. When the wires are disturbed, the vibrations in the wires are analyzed by a computer to determine if the vibration is caused by an intruder or a false alarm such as wind, rain drops or a bird sitting on the wire.
Read more on the Washington Post web site.
Visit the Penn State graduate program in acoustics site.
The 10th International Congress on Sound and Vibration, will be held in Stockholm, Sweden between 7-10 July 2003. The conference organisers have extended the deadline for submission of abstracts to 1st February, 2003. Currently there are over 200 abstracts that have been submitted and the titles can be viewed here.
Read more on the ICSV10 web site.
There are often new additions to this web site, apart from the news items on the front page. I have added a link What’s New that is accessed from the menus under Departments.
Ellula Sounds has developed inflatable loudspeaker enclosures. They are intended for portable laptop or MP3 players. Models include 10W RMS desk speakers and a 35W RMS subwoofer.