A brand new method sends sound to a particular individual with out listening to these round | Science | EUROtoday

The establishment itself acknowledges that “it sounds like science fiction.” A crew of scientists from the State University of Pennsylvania (USA) has created a method to ship distant sounds to a particular individual, with out anybody listening to him. In the experiment launched on Monday, the researchers have fired two unbiased beams of inaudible ultrasound, surrounding the recipient’s head, every on the one hand, and when crossing the face work together and comes the sound of the well-known choir of The Messiah From Händel: “Hallelujah! Alleluia!”. The authors call “audible enclaves” or “whispering rays” to these remote sound bubbles.

Mechanical engineer Jiaxin Zhong explains to this newspaper possible applications, such as receiving custom sound messages in public spaces. “Museums, libraries or exhibitions could offer individualized sound without the need for headphones,” he says. “Auto drivers could receive navigation instructions while passengers enjoy music without distractions,” adds Zhong, one of the main authors of the method. These personalized sound bags, states, could also facilitate confidential military communications, improve the experience of virtual reality and even create areas of silence in noisy environments, if you choose to selectively cancel unwanted sound. Its results are published on Monday in the magazine PNASof the National Academy of Sciences of the United States.

The experiment is promising, but has important limitations, according to Yun Jing, leader of the Revolutionary Acoustics Laboratory of Pennsylvania. First, the choir of The Messiah It is heard as on an old -tuning old radio. “To achieve a better sound quality we will need better ultrasound emitters, because those we are using now are very cheap acquired to perform the concept test,” explains Jing. Your team also explores artificial intelligence tools to offer a more clear result.

The distance is another relevant factor. The source of ultrasound is an acoustic goals, an ultradelgated material that is capable of modifying the waves that affect it. In the experiment, scientists have placed a doll a few centimeters from the issuer, but Jing states that they could create a sound bubble around a person located “a few meters” away. “The problem is that ultrasonic waves are attenuated in a short time within the air, so reaching 100 meters might be tough, except we have now very highly effective ultrasonic emitters,” he argues. The advantage of its ultrasound source is that it barely measures 16 centimeters in length, a compact format that would facilitate its applications.

Telecommunication engineer Juan Miguel Navarro, from the Catholic University of Murcia, collaborated more than a decade ago with Yun Ling in acoustic simulations of great enclosures. Navarro recalls that the targeting of sound has already been used for more than 20 years in security applications, such as long -range acoustic devices, considered non -lethal weapons because they emit painful sounds that use the enemy. “The novelty of the brand new examine is that it permits us to breed an ample sound bandwidth to transmit vocal and musical sign at low constancy,” says the engineer.

The Spanish Marcos Simón, a technical sound engineer, founded in the English city of Southampton the Audioscenic company, which develops devices capable of detecting the listener’s ears and sending the focused sound. Simon applauds the new work, in which he has not participated. “The methodology introduced is de facto novel and, so far as I’m conscious, it had not been attainable to implement one thing comparable beforehand,” he says.

The Spanish engineer, however, emphasizes that in his opinion there are “vital technological limitations” to use this concept. “In the first place, ultrasound speakers require very high energy levels, which implies high power consumption. In addition, to get ultrasound speakers to emit audible sound, second -degree intermodulation products are required [las señales surgidas por la combinación de ondas ultrasónicas]. This needs to generate a very high acoustic pressure, which raises doubts about possible effects in the human auditory system, especially considering that the levels of safe exposure to ultrasound are not yet completely defined, ”says Simon, visiting researcher on the University of Southampton. However, from a technological perspective, it nonetheless requires vital growth earlier than it may be utilized in sensible contexts, ”