One can speak for his shirt collar when he speaks in a low voice. However, this expression may have a literal meaning. Engineers from Massachusetts Institute of Technology (MIT), along with collaborators from Rhode Island School of Design, have created a new "acoustic cloth" that has surprising utility. It can be used to listen to the heart and answer calls.

The "piezoelectric" fiber was created by researchers using the inspiration of the human ear. According to Nature's study, the fabric converts sound into mechanical vibrations, then into electrical signals. It can detect different noises, from those made in quiet libraries to those from heavy traffic. Additionally, it can determine where a sudden sound like applause is coming from.

There are many practical uses for it. This fabric, when woven into a shirt lining can seamlessly interact with the skin of humans, allowing them to comfortably, continuously and long-term monitor and manage their cardiac and respiratory health," says Wei Yan (assistant professor at Nanyang Technological University, Singapore), who developed the fiber as MIT postdoc. He says that you can also use the fiber to "talk through it" and answer calls or communicate with other people.

Grace Noel, coauthor of the study, says that the invention could be used to aid hearing impaired people communicate better. "The performance of the membrane is comparable with that of a handheld mic," she said. To detect the source of a shot and to take cover.

It's not just that. Yoel Fink (another author) sees potential for it to be incorporated into maternity clothes to control the baby's heartbeat. Yan suggests more options: Yan envisions integrating it into spacecraft's surface to hear the space dust buildup, embedding it inside buildings to detect cracks and tensions, or weaving it into an intelligent network to monitor the fish in the ocean.