The U.S. Navy has invented a new device to prevent people from talking. The Acoustic Holographic Audio Disruptor (AHAD) records a person’s conversation and plays it back, disrupting their concentration and preventing them from speaking further. While it is an intriguing concept, it is uncertain whether this technology will be used on the battlefield.
This device disrupts their concentration and prevents them from speaking further.
AHAD was developed by engineers at the Naval Surface Warfare Center, Crane Division, a research and development facility of the Navy in Indiana specializing in handheld weaponry. According to a report by New Scientist, the patent was granted in 2019.
According to the patent illustration, the target’s conversation will be replayed back to them twice, once immediately and once after a short delay. This delay creates Delayed Auditory Feedback (DAF), altering the speaker’s normal perception of their voice. In normal speech, speakers hear their own voice with a slight delay, and their body has adapted to this feedback. By introducing a different audio feedback source with a long enough delay, the speaker’s concentration is disrupted, making it difficult to continue speaking.
The patent application even includes a link to this video, illustrating the process:
SpeechJammer
If you grew up with siblings, you might instantly recognize this “technology.” AHAD is essentially like an annoying sibling, repeating anything you say immediately, in a funny or annoying voice. The only difference is that siblings do it simply to irritate another family member, while a government agency using this system could employ it to prevent riots or other illegal gatherings.
The system can be used in a very stealthy manner, as the patent explains: By using directional microphones and speakers, the system will only capture the target’s voice, and only the intended speaker will hear the transmitted sound. A person targeted by AHAD may be shocked by this technology and confused that no one nearby can hear what they are hearing. Those around them may be equally puzzled when the person suddenly stops speaking and behaves strangely. In other words, it could make you feel like you’re going crazy and make those around you think you’re insane.
The interruption technique works best if the device repeats the speech one syllable after the speaker’s rhythm. Strangely, it is completely ineffective for some individuals, perhaps those with extremely high confidence, and may even enable some people to speak better. The effects are not consistent enough to make the technology practical in real-world applications.
Long Range Acoustic Device system on the USS Blue Ridge command ship
This technology has several other applications. It can be used as a conventional audio signaling device, possibly to give directions to a ship or to initiate a conversation. More intriguingly, by directing the AHAD system at a wall or corner, the AHAD system can also project sound to a target surface so that the sound emanates from that target.
AHAD falls under the category of non-lethal weapon systems, designed to achieve desired effects without causing permanent harm. The U.S. Navy has deployed other types of non-lethal acoustic weapons, including the Long Range Acoustic Device, which can transmit focused sound waves at very high decibel levels, causing pain. The pain forces people to flee from an area and can lead to prolonged physical effects, including migraines and tinnitus, lasting up to a week.
