Singers, teachers, call-center employees, coaches and politicians have one thing in common — they almost always use their voices when working. This means they are also at risk of vocal fatigue now and then. Fortunately, scientists found a way to help them prevent vocal cord strain and other injuries.

Northwestern University researchers recently developed a first-of-its-kind smart device that monitors people’s use of their voices and alerts them to potential overuse, fatigue and injury. The team responsible for the wireless wearable hopes it could be a game-changer for individuals who rely on their voices to make a living and communicate effectively.

The postage-stamp-sized device is soft and flexible and adheres easily to the upper chest, sensing vibrations whenever the wearer is talking or singing. Collected data is sent to the user’s smartphone or tablet in real-time, so tracking vocal activities are done throughout the day.

The smart device comes with custom-machine learning algorithms that help differentiate speaking from singing, allowing users to monitor different vocal activities separately. Cumulative total vocal usage is also measured, and users can set their personalized vocal thresholds.

Whenever the wearer is close to reaching the threshold, the accompanying app connected to the device via Bluetooth will provide alerts in the form of real-time haptic feedback. The notifications remind users when it’s time to take a break.

Vocal fatigue or injury affects everyone who is constantly speaking or singing. Overused vocal folds tend to swell, making the voice sound raspy and lose endurance. When a person constantly experiences vocal fatigue, they are at risk of suffering permanent damage that could derail their career.

“It’s easy for people to forget how much they use their voice. Seasoned classical singers tend to be more aware of their vocal usage because they have lived and learned," voice expert Theresa Brancaccio, who co-led the study, said in a news release by Northwestern University.

"But some people — especially singers with less training or people, like teachers, politicians and sports coaches, who must speak a lot for their jobs — often don’t realize how much they are pushing it. We want to give them greater awareness to help prevent injury,” she added.

Northwestern’s John A. Rogers, a bioelectronics pioneer, led the development of the wearable. He already had existing devices designed for similar purposes. The team helped him modify them to come up with one smart device capable of measuring vocal load over time using different parameters, including frequency, volume, amplitude, duration and time of day.

“I thought it was a great opportunity for us to extend our technologies beyond our very important, but narrowly targeted, uses in health care to something that might capture a broader population of users. Anyone who uses their voice extensively could benefit,” Rogers said.

Meanwhile, Brancaccio is hopeful that even non-singers would find the device helpful because keeping the vocal cords healthy is beneficial to all people. "Your voice is part of your identity—whether you are a singer or not. It's integral to daily life, and it's worth protecting,” she noted.

The research behind the new technology will be published in this week’s issue of the Proceedings of the National Academy of Sciences.

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Northwestern University researchers developed the smart device to help singers and other people who constantly use their voice. Northwestern University