Japanese researchers have developed a "SpeechJammer" gun than can be used to force people to stop speaking from more than 30 meters away. The device does not cause pain or physical discomfort to the target.
According to Kazutaka Kurihara of the National Institute of Advanced Industrial Science and Technology, and Koji Tsukada of Ochanomizu University, human speech is jammed by giving back to the speaker their own utterances at a delay of a few hundred milliseconds. The device works by recording the target's speech and firing the words back at them. This has an effect on the brain's cognitive processes causing the speaker to stutter and finally fall into silence.
According to the study paper titled "SpeechJammer: A System Utilizing Artificial Speech Disturbance with Delayed Auditory Feedback," the researchers Kurihara and Tsukada, said: "This effect can disturb people without any physical discomfort, and disappears immediately by stopping speaking."
Physorg.com reports that the device is based on the principle that the cognitive functions of speaking require a constant auditory feedback. According to Physorg.com, it partly explains why singers sing better when they wear headphones that allow them to hear their own voice as they sing. However, the cognitive processes involved is disrupted when there is delay between the time the words are spoken and the time the speaker hears the words. When there is such a delay, the speaker gets "discombobulated" and stops speaking. Scientists call this effect delayed auditory feedback.
Physorg.com explains that what the Japanese researchers did was that they attached a directional microphone and speaker to a box that holds a laser pointer and a distance sensor. The device has a computer board that computes the delay time based on the distance of the gun from the speaker. To operate the device, the user points it at the target like a gun with help of the laser pointer, then pulls the trigger.
The researchers, according to Fox News, found that the device was more effective when used on people reading aloud than on people engaged in "spontaneous speech." They also found that it was only effective when used on people saying something intelligible. For example, they found that it cannot stop someone making a meaningless sound such as "ahhh," over a period of time.
Kurihara and Tsukada, according to The Telegraph, said the device is effective for hushing people speaking aloud in a public library or for silencing people who interrupt others in group speeches.
The authors said: "There are still many cases in which the negative aspects of speech become a barrier to the peaceful resolution of conflicts."
The Japanese researchers have no plans to market the device because the technology is as simple as it is effective and it is doubtful they could patent it. It is already being speculated that a few years from now "Oscar winners [will be] jammed instead of herded offstage by increasing the music volume. Or hecklers in a crowd silenced at a moment’s notice." Technology Review also suggests a use for the device: "Clearly, speech jamming has a significant future role in contributing to world peace and should obviously be installed at the United Nations with immediate effect."
The potential legal implications of people carrying SpeechJammer guns are also noted. According to Physorg.com: "...new laws will have to be written to govern their use, of course, because no matter how much people would like to force others to shut up, they’ll hate it just as much when it’s pointed at them."