The sign language is widely used by deaf people around the globe. As the spoken languages, several sign languages do exist. The way sign language is learned by deaf people may have some details to be improved, but one can state that the existing learning mechanisms are effective when we talk about a deaf child, for example. The problem arises for the non-deaf persons that communicate with the deaf persons -the so-called listeners. If, for example, one couple has a new child that turns to be deaf, these two persons find a challenge to learn the sign language. In one hand, they cannot stop their working life, especially because of this sad news turns to be more costly, on the other hand, the existing mechanisms target the deaf-persons and are not prepared for the listeners. This paper proposes a new playful approach to help these listeners to learn the sign language. The proposal is a serious game composed of two modes: School-mode and Competition-mode. The first provides a school-like environment where the user learns the letter-signs and the second provides the user an environment used towards testing the learned skills. Behind the scenes, the proposal is based on two phases: 1 -the creation of a gestures library, relying on the Kinect depth camera; and 2 -the real-time recognition of gestures, by comparing what the depth camera information to the existing gestures previously stored in the library. A prototype system, supporting only the Portuguese sign language alphabet, was developed -the Kinect-Signand tested in a Portuguese Sign-Language school resulting in a joyful acceptance of the approach.

Part 2: Key ApplicationsInternational audienceSign language is the hearing impaired form of communicating with other people, including listeners. Most cases, impaired people have learned sign language form childhood. The problem arises when a listener comes in contact with an impaired person. For instances, if a couple has a child which is impaired, the parents find a challenge to learn the sign language. In this article, a new playful approach to assist the listeners to learn sign language is proposed. This proposal is a serious game composed of two modes: School-mode and Competition-mode. The first offers a virtual school where the user learns to sign letters and the second offers an environment towards applying the learned letters. Behind the scenes, the proposal contains a sign language recognition system, based on three modules: 1 – the standardization of the Kinect depth camera data; 2 – a gesture library relying on the standardized data; and 3 – the real-time recognition of gestures. A prototype was developed – Kinect-Sign – and tested in a Portuguese Sign-Language school and on eNTERFACE’13 resulting in a joyful acceptance of the approach