Ultrasound, privacy, marketing
Ultrasound describes the qualities of noises broadcast at frequencies too high for humans to hear. The DolphinAttack is one such hack, described in research carried out by a team at Zheijiang University in China. In this research, the team demonstrated that it was possible to broadcast inaudible commands that could activate devices and applications, like Siri or Google Now, that listen for audio commands.
The ramifications of using hidden commands to activate technology are immense. It has already been explored by the marketing industry, where the idea of ultrasonic beacons latching onto passing mobile phones seems very attractive.
In an interview with TechCrunch in 2014, a company called SilverPush said that it had already developed technology that used inaudible sounds, via websites or television, to retrieve data from the phones of its app users. What seemed like a good idea to the marketing industry was a disturbing thought to virtually everyone else.
In 2016, the Federal Trade Commission issued a warning to app developers on the Google Store who were employing the “audio beacon” technology to monitor users. SilverPush subsequently said it was no longer using its audio beacon software.
It’s easy to imagine, in a Black Mirror world, how secret signals could be used to switch off all the smartphone cameras during a protest.
Audibility in children
This idea of a sound that only the young could hear was recently resurrected with an acoustic deterrent known as the Mosquito. This was invented by Harry Stapleton, also from Wales, to keep kids from loitering around shops. It broadcasts an irritating high-frequency sound that only the young can hear. If it did breach human rights, one would also have to ban the Mosquito phone app, which teens use to annoy other teens. You can test your own hearing with one of the many online frequency hearing tests.
Haunting sounds
These are low-frequency sounds just under 20MHz, the lower limit of human hearing. The body reacts to the infrasound in a variety of ways. The eyeballs might vibrate and lead to the perception of something vague and indistinguishable on the periphery of your vision. There can be middle-ear pain, hyperventilation, and a sensation of fear or panic. Put those symptoms together in a supposedly haunted room and you get the “presence” that many people felt.
Infrasound also exists in nature. Elephants use it to communicate over long distances, and it’s produced by earthquakes, tornados, and ocean movement. It’s also said to be responsible for “the hum,” a phenomenon in which people hear some kind of persistent hum in the environment. The hum has been reported worldwide and has yet to have a satisfactory explanation.
Skyquake
For me, one of the scariest sounds that nature produces is the skyquake, an incredibly loud noise that appears to boom down from the sky. Exactly what produces this awesome racket is not known. You’ll find several theories online, from thunderstorms and earthquakes to the testing of top-secret aircraft. And it might be that not all of these sounds have the same origin. However, I can guarantee that if you hear a skyquake, you’ll be inclined to think angels are heralding the end of the world by blowing hard on their heavenly trumpets. It’s a curious cacophony, and when it occurs, it can be terrifying.
Voice in your head
You might think you’ve never experienced a voice in your head, but you’d be wrong. In fact, you are experiencing one right now. It is the voice you are using while reading this article. It’s also the voice you use when you talk to yourself. The reason I mention this universal voice in the head is the news that researchers at MIT have developed a headset that allows us to transcribe our inner voice. You can mentally ask it a question, and the headset responds with an answer that can be acted upon by one of your digital devices.
The sounds we hear around us are not always what they seem. We hear only a small spectrum of the sound in the world, and our brains have to do a very creative job of making sense of everything else.