A New Navy Weapon Actually Stops You From Talking

Interesting Engineering – by Christopher McFadden

The U.S. Navy has successfully invented a special electronic device that is designed to stop people from talking. A form of non-lethal weapon, the new electronic device effectively repeats a speaker’s own voice back at them, and only them, while they attempt to talk.

It was developed, and patented back in 2019 but has only recently been discovered, according to a report by the New Scientist.

The main idea of the weapon is to disorientate a target so much that they will be unable to communicate effectively with other people.

Called acoustic hailing and disruption (AHAD), the weapon is able to record speech and instantly broadcast it at a target in milliseconds. Much like an annoying sibling, this action will disrupt the target’s concentration, and, in theory, discourage them from continuing to speak.

It is important to note that the device is unlikely to be used on the battlefield anytime soon and will probably be used as a form of crowd control.

AHAD has been developed by engineers at the Naval Surface Warfare, Crane Division, a Navy research, and development facility in Indiana that develops handheld and crew-served weapons for the service.

As for the technical details of the device, a quick review of its patent is very interesting indeed.

“According to an illustrative embodiment of the present disclosure, a target’s speech is directed back to them twice, once immediately and once after a short delay. This delay creates delayed auditory feedback (DAF), which alters the speaker’s normal perception of their own voice. In normal speech, a speaker hears their own words with a slight delay, and the body is accustomed to this feedback. By introducing another audio feedback source with a sufficiently long delay, the speaker’s concentration is disrupted and it becomes difficult to continue speaking.”

If you want to see the thing in action, the patent filing handily also includes a sort of promotional video of another device that works in a similar way.

The device effectively annoys someone into not speaking

AHAD works by using a series of directional microphones and speakers that can target a speaker’s voice. The speech is then recorded and transmitted back in the same direction.

Interestingly, the broadcasted sound is on a narrow beam and will only be heard by the speaker. This will not only confuse the target but, ultimately, prevent them from being to concentrate and stop talking. The behavior of the target will be noticeably altered by the action, likely also confusing anyone who was listening to the target person. Put another way, such a weapon will make you think you’re going crazy — so too the people around you.

Such a technique will likely be most effective when the repeating speech is a syllable or two behind the real-time speech of the target speaker. You can think about how distracting this would be if you’ve ever experienced an echo of your voice on a phone call.

It is also important to note that devices like AHAD could have other applications too. For example, it could be used as a form of electronic hailing device between ships.

More intriguingly, as the patent alludes to, “by aiming AHAD system at a wall or corner, AHAD system can also project sound to the target surface such that audio appears to originate from the target.” AHAD now joins the tanks of other non-lethal weapons currently fielded by U.S. Armed Forces like, for example, the nonlethal Long Range Acoustic Device.

This sonic weapon is able to focus sonic waves at high decibel levels at a target leading to the target suffering from migraines, ringing of the ears, or mild pain and discomfort. Quite how the U.S. Armed Forces will deploy and use AHAD is yet to be seen, but it is guaranteed to annoy enemy combatants or domestic malcontents.

Interesting Engineering