Wednesday, June 10, 2009
What is it, what does it do, and how is it beneficial for the Deaf-Blind
By Scott Davert
The advancement of technology over the past fifteen years has opened many new doors to those who are deaf-blind. Scanners and optical character recognition software help deaf-blind individuals read printed material such as mail, e-mail allows those who are deaf-blind to network with one another, and the world wide web gives individuals who are deaf-blind access to lots of information previously inaccessible.
Another advancement in technology has been the evolution of global positioning systems (GPS). The purposes of this article are to explain what GGP is in general terms, how it effects the deaf-blind population, and my own experiences with this technology.
GPS (or global positioning system), is a satellite-based navigation system made up of a network of 24 satellites orbiting the earth at all times. This system, when the proper signals are received, allows a user to tell where they are located. Depending on many different factors, the accuracy can range from as close to 6 feet to as far away as 300. GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use triangulation to calculate the user's approximate location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. With distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map. The most basic way to explain what a receiver does is to think of it in terms of your television. In order to display the information sent out by a station, your TV must be able to first pick up the signal sent out by the station and then be able to interpret it. The better the reception of the signal, the clearer the picture will be.
The only information obtained from the GPS itself is the actual location of the user. The rest of the information available, such as nearby businesses, street information, etc, is actually determined by software installed on the receiver or something connected to this receiver. The software in the receiver or in whatever the receiver is connected to will take the information obtained from both the satellites and the map data it has, and allow a user to plan routes from two chosen points, tells the user of nearby locations, and approximates the user's speed and direction of travel.
Portable GPS systems are available to the deaf-blind population as add on to notetakers such as the Braille Note, Braille Sense and the Pac Mate. All three of the above mentioned products bring the power of GPS to the deaf-blind consumer. Whether you use speech and/or Braille output, these systems allow the deaf-blind population to access all of the information mentioned above. These Notetakers have both speech output as well as electronic Braille displays. For those with low vision, a GPS package on a mobile phone which utilizes screen magnification to enlarge the text on the phone's display is another possibility.
One of the many uses of GPS for me is when riding a city bus. While I do have some residual hearing, I do not have any vision. This makes it challenging to hear the announcement of where the bus is stopping. With GPS, this is no longer an issue. Further, I can use the "look around" feature in my GPS package, I can tell what streets and businesses I am passing by. I can even look up a specific business address and phone number.
Another experience I have had is through tracking a cab driver. This driver decided that since I was deaf-blind, he thought I would not know where he was going. He passed where I lived and continued on and turned on to another road. I asked the driver where we were going, and he said "We are almost there". I inquired as to what street we were on, and he gave me a location about a mile away. I told him that this was not correct and that he should turn around and go back to where I needed to go and not charge me extra for the traveling he decided to do. He was stunned, and apologized profusely for trying to rip me off.
While there are many benefits to GPS, there is one final point I'd like to make. GPS technology does give a deaf-blind traveler lots of useful information, however, these systems miss environmental information. While GPS technology can give you directions as to where to go, it does not take into account of whetherthere are any sidewalks along that route, addresses can be inaccurate, and so on. GPS is not a replacement for orientation or mobility skills, nor is it a replacement for any of the tools deaf-blind travelers already use such as a cane or service dog. It is, however, another powerful tool that can assist deaf-blind travelers in getting from one point to another effectively.
Editor's note: Scott Davert is a graduate student at Western Michigan University seeking dual masters' degrees in rehabilitation teaching and vocational rehabilitation counseling. Mr. Davert has previously taught deaf-blind consumers on assistive technology while doing internships at HKNC in 2006 and 2008. He will return to HKNC this summer to do another internship in the assistive technology and communications learning departments. He is also the Vice President and webmaster of SHI-M=DB, a consumer organization for people with combined vision and hearing loss in Michigan.