Sonic technology that allows audio to be specifically directed at a limited audience, as opposed to booming sound out as far and as loud as possible, has been around for a good many years but has yet to penetrate the mass consumer market. That situation could well change very shortly, however, thanks to the Soundlazer. The low-cost, pocket-friendly, open source, and completely hack-friendly parametric device developed by Richard Haberkern uses ultrasonic carrier waves to transmit sound from a connected music player on a narrow beam to a select listener.
Haberkern says that his Soundlazer project was inspired by the kinds of sonic experiments undertaken by companies and research labs for decades, in which sound is transmitted over a narrow ultrasonic beam so that someone stood close by the listener would not be able to pick up any of the source audio. It's fair to say, though, that in spite of promising successes like the Hypersonic speaker system demonstrated during a TED talk in 2004 by Woody Norris, the consumer market has not been exactly flooded by parametric speaker systems.
Work on the Soundlazer system actually began a few years ago, sourcing components and tweaking the design until it was finally ready for its public spotlight earlier this year. Haberkern decided to list the project on the Kickstarter crowd-funding portal in March, to both gauge interest in the project and raise enough cash to get production moving. At the time of writing, the directional speaker system has already received a good deal more than its initial target of US$48,000 and still has a couple of weeks left to run.
Soundlazer works by sending an audio signal from a digital media player, smartphone or computer/laptop to a built-in ADAU1701 digital signal processor for enhancement prior to transmission to an oscillator where an electrical signal is produced that rapidly switches on and off at 40,000 times per second. This signal is amplified and routed to the unit's 39 piezo ultrasonic transducers responsible for Soundlazer's directional audio beam. Haberkern apparently decided on including 39 emitters as a happy trade-off between effective range and device affordability.
The wide variety of potential applications for the technology appears only to be limited by imagination. A user could, for example, share music with a friend without annoying family or colleagues in the same room. The town where I live has a quaint public address system that runs a kind of local radio station on market days, and with a directional speaker system in place, those that live in the houses above the market need not be bothered by the relentless racket from below. Vandals or burglars could be discouraged from undertaking their particular unpleasantness by pointing uncomfortable audio at them only from a remote security office, or perhaps even by using a suitably created smartphone app.
The system outputs 120dB at 40kHz, which Haberkern says shouldn't be a problem for prolonged listening so long as the recipient is at least five feet (1.52 meters) away or bounces the signal off solid objects like walls.
Soundlazer has been developed to encourage sonic experimentation by the user. The basic kit comprises a fully functional circuit board with power supply and audio cable, and is being offered to backers who stump up at least $175. Each device will come with a complete set of design files and programming instructions, and the unit's board includes a programming port for interfacing with Analog Device's Sigma Studio DSP developing environment, which will allow users to expand the device beyond its supplied capabilities or just tailor the sound by creating custom waveforms. At this pledge level, however, this software will need to be purchased separately.
Backers who pledge $500 will find the Sigma Studio software and programming cable included with a Soundlazer that's been nicely housed in a rather swish red anodized aluminum outer case with black stand.
There's no word on post-Kickstarter pricing or availability, but backers should start to receive their fully-functional units from August.
