Tokyo-based Smartmedical, the medical service platform developer, announced on April 5 that it has launched the first vocal emotion-recognition app for the Apple Watch. Deemed EmoWatch, the app identifies and tracks users' emotions through their voices, rather than language. 

The app utilizes vocal recognition technology known as Empath to analyze voice properties, such as pitch, speed and volume. With this data, it charts users' "energy points," which contribute to a barometer that measures their level of energy.

"EmoWatch enables users to easily measure and monitor their emotional state," said Takaaki Shimoji, a Smartmedical Corp. board director. "All they have to do is speak to their Apple Watch. In order to maintain healthy mental well-being, it is very important to be aware of one's mental state. The app tracks and charts mental states so that users can check their mood in any situation."

EmoWatch's barometer shows the proportion of four key emotions: joy, calm, sorrow and anger. Shimoji went on to say that, although the emotion-recognition technology can analyze other mental states, it can be difficult to interpret several emotions if there are more indicators than necessary.

"The app gauges a user's well-being, detecting whether their mental state is positive or negative," Shimoji continued. "We created this original barometer by analyzing correlations with POMS (Profile of Mood States) scores."

POMS is a psychological rating scale designed to assess mood states. It consists of six key standards, although the EmoWatch condenses them down to four: tension-anxiety, depression-dejection, anger-hostility, fatigue-inertia, vigor-activity and confusion-bewilderment.

Smartmedical has made its Web Empath API available to developers online. Individuals can sign up to gain insight into the voice emotion-recognition technology. 

Apple Watch owners who want to take advantage of the EmoWatch app can do so by downloading it from the App Store. Smartmedical positions EmoWatch as a "mental health app," and the description of the app itself states that it can be helpful for "keeping good mental well-being in various situations." 

In 2015, Empath won the Japan Resilience Award. It has been refined through collaborative research programs at facilities, including the University of Tokyo and Nara Institute of Science and Technology.