ABSTRACT: This paper describes the development of a system that uses a portable Pocket PC to generate 3D spatialized sounds, based on the readings from a multidirectional sonar system that detects obstacles around a blind person. The distances from the user position to the closest objects in six directions are continuously determined using six sonar range meters.
The information is used by the Pocket PC to create a 3D sound environment that represents the obstacles in these directions through the simulation of six spatialized sound sources. The dynamic spatialization of the sounds is achieved through the use of previously computed Head Related Transfer Functions, taking into consideration the distance to the obstacles, and the direction the person is heading. The paper explains the process followed by the Pocket PC to acquire the signals from the sonar system, and the real-time creation of the 3D sound environment that would help a blind person locate nearby obstacles in his or her navigation environment. This system may facilitate the navigation of blind individuals through indoor environments, since it provides the user with information that is different from that collected through the use of a cane. This system explores the presence of obstacles in all six directions around the user simultaneously, and it can provide an indication of obstacles even if they are farther away from the user than the radius covered by the reach of the cane.