Researchers at MIT have developed a new acoustic fabric that converts audible sounds into electrical signals, offering new listening opportunities for the hard of hearing.
The team developed an acoustic fabric woven with a fibre that is designed from a ‘piezoelectric’ material, capable of producing an electrical signal when bent or mechanically deformed, creating electrical signals from sound vibrations.
The fibres can be made to capture sounds ranging in decibel from a quiet library to heavy road traffic, determining the precise direction of sudden sounds such as claps.
The fibres can also be made to generate sound, such as a recording of spoken words which another fabric can detect.
The fabric is designed to work like a microphone, converting sounds into mechanical vibrations, then into electrical signals in a manner similar to how the human ear hears. The researchers suggest that a directional sound-sensing fabric could help people with hearing loss to tune in to a speaker amid noisy surroundings.
The researchers also reversed the fibre’s function to serve as a speaker, recording a string of spoken words and feeding the recording to the fibre in the form of an applied voltage. The fibre then converted the electrical signals to audible vibrations, which was detected by a second fibre.
Wei Yan, lead author, explains: “Wearing an acoustic garment, you might talk through it to answer phone calls and communicate with others.
“In addition, this fabric can imperceptibly interface with the human skin, enabling wearers to monitor their heart and respiratory condition in a comfortable, continuous, real-time, and long-term manner.”