Tangible Acoustic Interfaces (TAI’s) are a particular class of tangible interfaces that rely on various acoustic techniques in order to determine interaction parameters such as the position of contact and the nature of the contact with the interface. TAI’s are closely related to the sense of touch, by the mean of the acoustic vibrations that are produced when touching or manipulating an object, either with the hand or with another object (e.g. a stick or a pen). By analysing those vibrations, it is possible to determine where and how the object is touched, thus providing a complete description about the tangible interaction.

The European project TAI-CHI (Tangible Acoustic Interfaces for Computer-Human Interaction) [2004-2006] was led by Cardiff University (UK) and included 7 partners across Europe, spanning from fundamental research in acoustics to prototype applications, and building around two platforms, EyesWeb on the software side and SenseWeb on the hardware side. The project led to new technology breakthrough, such as the continuous tracking of fingers touching a surface or the use of 3D objects. For more info, please consult the project’s web site: http://www.taichi.cf.ac.uk/

We have realised several demonstrators based on TAI technology, such as the Sound Rose installation, the Touch Table and the Percussion Tray. We have been also involved in the realisation of some non-musical demonstrators, such as the light globe demo shown on the left, realised in collaboration with the Laboratoire Ondes et Acoustique (LOA) in Paris : virtual switches are created on the surface of the globe using two piezo sensors fixed near the base of the globe and sensing the vibration when taping on it.