People such as singers, public speakers and teachers run the risk of injuring their vocal cords through overuse. An experimental wearable system is designed to help keep that from happening, by warning users as they approach their vocal threshold.
The setup is being developed by "a team of materials scientists, biomedical engineers, opera singers and a speech-language pathologist," led by Northwestern University's Prof. John A. Rogers. It incorporates two devices: a sensor that is adhered to the skin over the wearer's sternum, and a haptic feedback unit which is worn on their wrist. Both are wirelessly linked via Bluetooth to an app on the user's smartphone.
The sensor continuously detects the vibrations of the wearer's vocal cords – but not any external noises – transmitting its readings to the app. Machine-learning-based algorithms then process the data, ascertaining the frequency, volume, amplitude and duration of all the user's vocalizations, along with the times of day at which they occur. The algorithms are also more than 95% accurate at differentiating between singing and talking.
If the app determines that the person is getting dangerously close to the specific threshold which they previously set for themselves, it warns them by causing the haptic feedback unit to vibrate. The user then knows to shut up for a while – or at last quiet down a bit – in order to give their vocal cords a rest. Even a break of just 15 to 20 minutes may suffice.
A display on the app provides more information on the user's vocal activity, along with recommendations for resting appropriately. And importantly for the privacy-conscious, the system does not record what the user is saying.
"It’s easy for people to forget how much they use their voice," said Theresa Brancaccio, a Northwestern lecturer and voice expert who co-led the study. "Seasoned classical singers tend to be more aware of their vocal usage because they have lived and learned. But some people […] often don’t realize how much they are pushing it. We want to give them greater awareness to help prevent injury."
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.
Source: Northwestern University