MIT researchers have developed an ultrathin material that can turn any rigid surface into a high-quality audio speaker. The team showed off a hand-sized speaker that weighs about as much as a dime, and uses far less energy than a traditional loudspeaker. One possible application is noise cancellation in noisy environments, such as an airplane cockpit.

https://scitechdaily.com/mit-engineers-develop-a-flexible-paper-thin-loudspeaker/