Apparatus for recording, transmission and reproduction of sound or images; data processing equipment, computers; electronic tablets, namely, PC tablets, tablet computers and electronic writing tablets; software being recorded programs for collecting, processing and fusionning data from distance and inertial sensors; computer peripherals; electronic navigation apparatus for mobility assistance for disabled or non-disabled persons; electronic navigation apparatus for mobility assistance using ultrasound; navigation aids, in the nature of satellite-aided navigation systems, inertial navigation systems, radio navigation systems and obstacles avoidance systems primarily comprised of sensors for measuring proximity to objects and GPS navigation devices for disabled or non-disabled persons; electronic apparatus for navigation assistance using ultrasound; mobile apparatus, instruments and equipment for data processing; mobile apparatus, instruments and equipment for the transmission, reception, processing and reproduction of sound, ultrasound or other signals; mobile apparatus, instruments and equipment positioned on a limb being part of the body or a cane for the processing of data from surroundings, namely, computers, computer hardware, data and digital signal processors, inertial sensors, GNSS receivers, electronic proximity and distance sensors; apparatus connected to mobile telephones or tablet computer, namely, electronic sensors and computers, earphones and loudspeakers; apparatus connected directly or via an intermediate apparatus to the Internet, namely, computers, tablet computers, and mobile phones; computer software applications for mobile phones or tablet computers, namely, electronic travel aid software for disabled or non-disabled persons that provides directions, point-of-interest information and obstacles avoidance