The primary mobility aids used by blind and partially sighted students are likely to be the Guide Dog, the long cane, and personal helpers (e.g. Buddies). Other recent technological innovations include tactile maps, various electronic travel aids and personal navigation kits.
Electronic travel aids (ETAs) are designed specifically for use outdoors, and have been the subject of considerable research and development over many years (Foulke, 1986). There has been some debate (Heyes no date, a) as to whether such devices should attempt to provide a complete non-visual 'map' of the immediate environment (i.e. a vision substitution system), or whether they should provide a small amount of information on a specific characteristic of the environment (e.g. a mobility support aid).
The Sonic Pathfinder falls clearly into the second of these categories, and is designed specifically as a supplement to other primary mobility aids. This is a head-mounted device which provides a simple tonal display that provides advance warning of objects that lie in the user's travel path (Heyes, no date, b). It is a highly selective aid, providing information only of immediate practical use to the pedestrian, and prioritising objects lying straight ahead of the user. As with data sonification devices, training in the use of ETAs is essential. In the case of the Sonic Pathfinder, training has to be provided by specialist trainers, and takes several sessions spread over the best part of a week.
A more advanced and integrated system, involving the use of GIS and GPS technology, has been developed as part of the Personal Navigation Assistant project (Golledge et al., 1991; Loomis et al., 1998).
See the following related documents in this guide: Assistive Technology; Travel; and Getting Around.
Page updated 14 December 2001
GDN pages maintained by Phil Gravestock
© Geography Discipline Network/authors, 2001
ISBN: 1 86174 115 4