MAKE: Blog: How LRAD works

How LRAD works

HowStuffWorks has a great article on how LRAD works -"In November of 2005, pirates attacked a cruise ship off the coast of Somalia. The pirates had machine guns and rocket-propelled grenades. But the cruise ship had a Long Range Acoustic Device (LRAD), which was credited with driving the pirates away by firing a beam of sound. Learn what makes sound a weapon and explore other uses for the LRAD." - Link.

Pictured here, Woody Norris with his LRAD from MAKE 05.

Related:

Woody's World- A Q&A with the inventor of a pirate- scaring noisemaker, a helicopter for every garage, and a way to hack gravity itself. From William Lidwell's article "Woody Norris is standing 50 feet away from me, pointing a menacing-looking sci-fi contraption at my head. We're in the back lot of his American Technology Corporation in San Diego, Calif. Woody's device is called the LRAD (for Long Range Acoustic Device). It looks something like a big spotlight, the main difference being that it projects sound instead of light. Woody yells to me, "We are going to start with some music. This is really cool!"... MAKE 05 - Page 30.
More from Woody Norris - In this exclusive web extra, the conversation with Norris continues. Learn Norris' views on inspiring creativity, selling yourself along with your inventions, learning when to quit, and why inventors shouldn't be afraid someone will steal their idea - PDF.

Related:

Comments

Oldest comments listed first.

Posted by: JFields on March 7, 2006 at 9:29 AM

This is one of my favorite sites.

I was really enjoying the Woody Norris interview posted in the PDF, but it's cut off in the middle. Can you please post the full article?

Posted by: philliptorrone on March 7, 2006 at 9:32 AM

the full article is in MAKE, if you're a subscriber you can log in and read it right now.

Posted by: Phodio on August 1, 2006 at 12:28 PM

I can confirm the Long Range Acoustic Device LRAD has been in use for years now among other issues to avoid maritime piracy and to give information to big crowds and demonstrations.

It is a great tool as one can communicate to the counterpart in several hundreds meter distance. Thereby it helps to avoid dangers situations. E.g. demonstrants and police officers - as long as they do not get in touch they can not start a fight.

Also it can be used in case of disaster. The authorities can inform and warn the population very efficiently using the LRAD for long distance messaging.

You should see the LRAD as a kind of megaphone. It gives normal acoustic messages, however good engineering work have made it possible to narrow the sound beam.

Have a look at this LRAD video presentation to understand the product and what it can do LRAD - Long Range Acoustic Device

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