Unwanted noise plagues our daily lives, from traffic rumbles to loud neighbours and chatty colleagues. Researchers at MIT, in collaboration with other institutions, have created a solution: a special silk fabric, as thin as a human hair, that significantly reduces noise levels.
This innovative material contains a hidden superpower – a fiber that activates when charged with electricity. When sound hits the fabric, it triggers vibrations that counteract the noise in two ways. Inspired by noise-cancelling headphones, the fabric’s vibrations create a “symphony of silence” by emitting sound waves that interfere with unwanted noise, similar to how musical notes can cancel each other out.
The practical applications are vast. Made from everyday materials like silk, canvas, and muslin, this noise-suppressing fabric can be seamlessly integrated into real-world environments. Imagine dividers in open-plan offices constructed from this fabric, or thin walls that effectively block sound transmission in homes.
“In a world overflowing with noise, our aim was to create silence, a valuable commodity even more precious than gold,” said lead author Grace Yang. “By harnessing the power of fabric vibrations, we’ve opened a new door to designing quiet spaces.”
The fabric’s noise-cancelling prowess extends beyond vibrations. The researchers discovered that keeping the fabric still also disrupts sound waves, acting as a sound barrier for walls and dividers. In an unexpected turn of events, they found that the quiet fabric reflects sound like a mirror reflects light.
Experiments revealed that both the fabric’s mechanical properties and pore size affect its sound-generating efficiency. While silk and muslin share similar mechanical properties, silk’s finer pores make it a superior fabric loudspeaker.
Testing the fabric in direct suppression mode demonstrated a significant noise reduction of up to 65 decibels, roughly equivalent to loud conversation. In vibration-mediated suppression mode, the fabric achieved an impressive 75% reduction in sound transmission.
The research team is looking ahead, exploring ways for the fabric to block sound across multiple frequencies. This will require advanced technology and improvements in the fabric’s manufacturing process. Additionally, they aim to optimize the fabric’s performance through design modifications.
“The possibilities are endless,” said Yang. “We’ve just begun to tap into the potential of this sound-suppressing fabric. This is the dawn of a quieter, more peaceful world.”