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A sophisticated speaker system, described as a "bull-horn on steroids," may be one of the most effective weapons designed at repelling hijackers on the high seas, according to an anti-piracy expert.

Magnetic Audio Devices (MAD) can work to steer pirates away before an encounter escalates into violence, according to developers behind the system.

Currently, captains use the laser-like speakers to inform potential attackers the ship knows they're there from more than a kilometre and a half away -- that's farther than the naked eye can see.

But experts say on full blast, MAD speakers are powerful enough to knock someone off their feet.

Instead of blindly firing at an unco-operative pirate boat, the MAD speakers can also send shrill police tones piercing over the waters. Experts behind the technology claim the sound is so powerful that it irritates, and in some cases could disorient, attackers.

Former military pilot and U.K.-based Anti-Piracy Maritime Security Solutions manager Nick Davis advises shipping companies to use MAD equipment onboard.

"It's a very well proven and very effective deterrent," Davis told Â鶹ӰÊÓnet on the line from Busan, South Korea on Thursday.

At a maximum of 145 dB (decibels) and 2,000 Hz (hertz), MAD would deafen the average human standing 100 to 200 metres away, he said.

For now, the speakers on merchant vessel and oil ships aren't strong enough to permanently damage a target's hearing.

Operators standing behind the device are out of harm's range, Davis added.

This year alone, more than 80 ships have been hijacked off the coast of Somalia. The pirates have become increasingly brazen in their attacks, leaving companies scrambling to keep their ships, crew and cargo safe.

Inventor Vahan Simidian developed MAD several years ago after the U.S. government asked for a device to keep the "good and bad guys" away from each other long enough to implement appropriate defence measures.

Simidian demonstrated the technology with the least powerful of the MAD models on Canada AM on Thursday. The handheld device, which looks like a three-tier megaphone, weighs only four kilograms but can communicate roughly a half of a kilometre away with zero distortion.

"It's what you'd call a bull-horn on steroids," Simidian said, adding that the unit sells for about $3,000.

Whether you speak loudly or softly, it's "unbelievably clear," he said.

The technology uses planar magnetic transducers to produce crystal clear sound.

"This technology, believe it or not, when pointed at a window energizes that window and the sound can continue right into the vehicle or the boat or wherever it is," Simidian said.

Some ships are more vulnerable to pirate attacks than others. Fully loaded boats typically travel less than 20 knots making them sitting ducks for pirates.

Ship crews can use other non-lethal methods to protect themselves against attackers, including hanging barbed wire around deck, flooding the ballast tanks and spraying fire hoses on full power in an effort to push assailants overboard.

But MAD technologies could prevent pirates from boarding a vessel in the first place.

"It's quite unique," Simidian said.

The concept of MAD sound dates back to 1923, but Simidian and his team at HPV Technologies Inc., based in California, made it work about seven years ago.

The speakers were tested at the Edwards Air Force Base in California with the help of 50 scientists from all over the world.

Simidian is already working on a similar two-way acoustic technology.