(Health Korea News / Lee Chang-yong) An artificial acoustic sensor that can detect specific sounds by precisely simulating the cochlea in the actual ear has been developed. A device that has high-sensitivity hearing like a movie character with superpowers and can selectively detect only danger signals is expected to enter our daily lives.
A research team led by Professor Han Chang-soo and Dr. Jeon Eun-seok of Korea University announced on the 24th that they had developed a next-generation wireless, multi-channel acoustic sensor capable of frequency separation and detection by mimicking the process by which the human cochlea perceives sound.
Among the human auditory organs, the cochlea is located at the innermost part of the ear and functions to change sound vibrations (frequency) into electrical signals and transmit them to the brain. If you unfold the spirally wound cochlea, you will find a very thin cell boundary membrane called the basilar membrane along the inner tube. The base, which is the beginning, is wide and thin, and as it reaches the top (apex), it becomes narrower and thicker.
The shape of the basilar membrane in the cochlea allows us to perceive a variety of sounds divided into different frequency bands.
Research on acoustic sensors that mimic these biological functions has been ongoing for the past 20 years, but acoustic sensors developed through existing research had limitations in detecting and analyzing sounds, such as a narrow frequency band and insufficient frequency band separation between multiple channels.
The research team developed a next-generation artificial basilar membrane sensor that more precisely mimics the shape of the basilar membrane of the cochlea. They developed a new method to effectively reflect the three-dimensional structural characteristics of the biological basilar membrane and reflected it in the design.
The artificial basement membrane structure was designed to have a width that changes along the length direction like a biological basement membrane. By adopting a spiral structure, the length per area was made as long as possible, greatly expanding the frequency band.
By imitating the basilar membrane and auditory nerve, 24 piezoelectric sensor modules were attached so that each of the 24 channels can have an independent frequency band. This allows the formation of a desired characteristic frequency depending on the location of the basilar membrane, and suggests the concept of minimum distance to the basilar membrane.
Using the wireless acoustic sensor developed in this way, we analyzed the driving sounds of high-speed, heavy-duty vehicles such as buses, trucks, and motorcycles running on actual roads. As a result, we demonstrated the ability to separate frequencies and detect and analyze electrical signals, such as distinguishing the type of vehicle based on sound alone.
Regarding this study, a professor said, “It is expected that it can be utilized as an early warning system that can detect danger signals in advance in noisy environments,” and “It also seems that it will be very effective in hearing assistance devices such as artificial cochleas.”
The results of this study were published in the June 17th issue of ‘Advanced Science’, an international academic journal in the field of materials.
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Source: www.hkn24.com
