Scientists invent artificial cochlea to boost performance of hearing aids

It mimics the function of hair cells found in the ear.
Loukia Papadopoulos
An illustration of the human ear.jpg
An illustration of the human ear.

Chainarong Prasertthai/iStock 

Researchers at Technische Universität Ilmenau, Kiel University, University College Cork, Karlsruher Institute of Technology, and Fraunhofer Institute for Digital Media Technology Ilmenau have engineered a microelectromechanical sensor inspired by the human cochlea that can process sounds and detect individual signals in noisy environments more effectively than current microphones.

This is according to a report by Tech Xplore published on Tuesday.

"The idea for the research was to build artificial hair cells, similar to the hair cells in the inner ear, which are responsible for the sound detection in the human ear," Claudia Lenk, lead author of the paper, told the science news outlet. 

"We were inspired by the previous work by Bryan Joyce et al., who used cantilevers with complex feedback to achieve the specific properties of the hair cells. We thought that we can create artificial hair cells quite easily and efficiently since we have a specific type of cantilevers (silicon beams) which can be read out and actuated completely electronically."

Mimicking hair cells

The invention mimics the different hair cells contained in ears that are responsible for detecting distinct tones.

"Hair cells in the ears can be individually tuned, in particular the gain for detection, and thus how each tone is detected can be adjusted," Lenk explained. 

"This is important if we want to separate, e.g., speech from background signal. In this case, the gain would be high for the tones belonging to the speech signal and low for the background signals. In this way, background and speech can be much easier be separated."

The invention consists of two key components: a series of small silicon cantilevers designed to act as artificial hair cells and a feedback loop that tunes the detection properties of each cantilever individually.

"We successfully implemented the properties of human hearing directly in the sensor via a quite simple and fast feedback loop," Lenk told Tech Xplore

"This has two big implications. Firstly, the system is rapidly adaptable, and this is quite important for application in various situations. The cochlea's bio-inspired properties also help to highlight important information like when a sound started or specific tones, which should help to make the processing (e.g., speech detection) faster and more efficient (i.e., smaller neural networks necessary for processing)."