This R&D project implements a new way of perception of the three-dimensional surrounding space, based exclusively in sounds and thus especially useful for the blind. The innate capability of locating sounds, the externalization of sounds played with headphones and the machine capture of the 3D environment are the technological pillars used for this purpose. They are analysed and a summary of their main requirements are presented. A number of laboratory facilities and portable prototypes are described, together with their main characteristics.