We will know how to "talk" under water

"The inspiration for this research project was the situation when I was completely unable to communicate under water with another diver" - said Łukasz Nowak of the Institute of Fundamental Technological Research PAS in Warsaw, coordinator of the project of building a device called a "bionic sonar".

 

Communication between divers under water is quite complicated, typically achieved with a variety of gestures. It would be much easier to take rebreather out for a moment and just say something.

 

"Unfortunately, this does not work, which you can easily check yourself, for example at a swimming pool. Firstly, breath bubbles make much noise and interfere: they vibrate and become a source of sound. Secondly, our voice does not really want to leave the mouth: it bounces back from the boundary of the water due to differences in the density and speed of sound in water and air" - explained the scientist.

 

Our voice also propagates as vibrations of the throat, neck, head parts, but in this way we are not able to emit sound with sufficient levels in water. Dolphins can do this because their voice system has adequate tissue that matches its parameters to the water. "We are looking at dolphins, specifically their anatomy and specific body structures that enable the production of sounds of different frequencies, and the penetration of sound into the water" - described Nowak.

 

The researcher explained that the sound waves made by dolphins are propagated in their bodies, they are reflected in specially shaped air chambers inside the head, pass through a number of tissues with different properties, matched to allow smooth passage of generated signals into the surrounding water.

 

Scientists from the Institute of Fundamental Technological Research PAS are now checking whether the human voice system can be adjusted to the water in a similar way. If they come to a positive conclusion, they will be able to build a device called a bionic sonar. It is used to obtain information about the surrounding environment using acoustic waves.

 

"The system can be imagined as a voice system extension, something you can put to your mouth, head or throat, and it will allow the transmission of sound into the water. Other person will be able to hear this sound now without any equipment, because the transmission of acoustic waves from water into the hearing system does not faces such obstacles" - said the researcher.

 

The device can be useful for recreational divers, technical divers, but not only for them. Some marine mammals, including dolphins, use sound to navigate, locate and communicate underwater. Therefore a bionic sonar can be used to detect objects, collect detailed data on their location in space, speed, size and object type. It can be used, for example, for the location of unmanned underwater vehicles.

 

Scientists want to develop an active sonar, one which would emit sound waves and listen for returning signals. It consists of several main components: acoustic wave generation and emission system, receiver that registers incoming acoustic waves. Another component is the data processing system that analyses the received acoustic wave parameters, compares them with the parameters of emitted signal, and through a series of operations provides required information.

 

"For now, our work focuses mainly on sound wave transmission and receiving systems. We are also working on the preparation of patent applications for specific solutions" - explained Nowak. Scientists from the Institute of Fundamental Technological Research PAS are working on the project together with researchers from the Medical University Gdańsk and the University of Gdańsk.

 

Source: PAP - Science and Scholarship in Poland, Ewelina Krajczyńska