TSU radiophysicist creates a directional speaker for audio broadcasts

28 December 2019

Fedor Emelyanov, radiophysicist at Laboratory of Siberian Physics and Technology Institute, is developing a multi-beam sound speaker that will be able to transmit signals directionally: two different sound messages will be heard only in certain locations. This technology will be useful for audio excursions in museums and exhibitions, for audio advertising or at concerts.

- This speaker will transmit sound directionally. For example, there is a speaker in the room and there are many people around. In a certain place, people will hear a message, but as soon as they leave a given area, the sound will disappear, - said Fedor Emelyanov. - Today, such speakers are used at exhibitions, in museums, and in stores. For example, it was an experiment: in a store, there was a basket with bananas, and in one particular place people heard a voice advertising bananas. As a result, the sale of bananas increased almost 2 times.

The uniqueness of the TSU radiophysicist development is that one speaker will transmit two different signals to different places, the estimated radius of action is up to 50 m. That is, in the crowd one person behind a given place will hear the first message, the other in another location will hear the second message, and the rest will hear nothing.

- We conducted a preliminary experiment in which the speaker generated two ultrasonic signals at frequencies of 40 and 41 kHz and emitted them simultaneously. Because air acts as a transducer, these waves are added and subtracted. The human ear perceives frequencies from 20 Hz to 20 kHz, and then the sound with a frequency above 20 kHz is ultrasound. When the signal frequencies add up, it turns out the inaudible frequency of 81 kHz, but when subtracted, then it turns out 1 kHz, and this is the audible range. In this case, a person can hear the signal transmitted from the speaker, - explained Fedor Emelyanov.

As a result, the radiophysicist will create a multi-beam directional speaker, and the number of sound transmission channels will be its main advantage both in the technical part and in the price.

The speaker will be equipped with a USB port or Ethernet, which will help to connect different devices to it. Due to its small size, it will be convenient to operate and place in various rooms.