From: empower@smart.net
Subject: Presentation of latest research on Talking Signs technology
I'd like to submit the article below as a discussion item for this list.  
I have some thoughts about it, pro and con, though would prefer 
to hear from others first.  Anyone wish to begin a discussion?
Regards,
Jamal
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From the web page http://www.dinf.org/csun_98/csun98_063.htm
 CSUN 98 Papers 
TALKING SIGNS (R) REMOTE INFRARED AUDIBLE SIGNAGE FOR TRANSIT
STATIONS, SURFACE TRANSIT, INTERSECTIONS AND ATMS.
                      Bill Crandall, Ph.D.
                      Smith-Kettlewell RERC
                       2232 Webster Street
                    San Francisco, CA. 94115
                       B.L. Bentzen, Ph.D.
                 Accessible Design for the Blind
                        Linda Myers, M.Ed.
                Marin County (CA) Public Schools
The most common signage for people who are blind is restricted
to tactile displays. This requires persons to be at the location
of the signs before they can identify the information it bears.
Using such signage as an aid in locating and traveling to a
telephone booth, bus stop, elevator, public electronic terminal,
building entrance or exit, leads to the paradoxical effect of
having to already be there before one knows where it is. In
addition to the problem of locating specific travel goals, very
often blind travelers are unaware of the many amenities that
sighted travelers encounter in a purely serendipitous fashion.
Remote Infrared Signage is particularly appropriate for open
spaces where tactile signs are inappropriate; they label the
environment for distant viewing. Remote infrared signs allow
people to directly know not only "what" choices are available to
them, but "where" in the environment these options are. Just as
sighted persons visually scan the environment to acquire both
label and direction information, remote infrared signs directly
orient the person to the labeled goal and constantly update the
person as to his progress to that goal. That is, unlike Braille,
raised letters, or voice signs which passively label some
location or give mobility instructions to some goal, remote
infrared signage provides a repeating, directionally selective
voice message which originates at the sign and is transmitted to
a hand-held receiver. The direction selectivity is a
characteristic of the infrared message beam and ensures that
persons using the device gets constant feedback about their
relative location to the goal as they move towards it.
An analysis of the National Center for Health Statistics
estimated that 4.3 million non-institutionalized people in the
US had difficulty reading the newspaper with their corrected
vision -- a functional definition of perceived limitations
termed Severe Visual Impairment (Nelson and Dimitrova, JVIP,
March, 1993). An additional 2.3 million people also reported
difficulty with seeing medium to far distances. Another recent
study (Chiang, et. al., Milbank Quarterly, 1992) estimates 1.1
million people are Legally Blind under the definition of tested
acuity (<20/200). Data from the Bureau of the Census put the
figure for this same level of impairment at 9.7 million people
(McNeil, 1993). Many other disabilities prevent persons from
reading print. In addition to people who are blind or have low
vision and may not be able to see the print, there are many
stroke, head-injured, autistic and dyslexic (or even just
educationally impaired) persons who may not be able to
assimilate printed language even though they can see the page.
Many people can accept this information through speech. During
the past three years of human factors research we have
established that blind people using Talking Signs can easily
learn to use the system effectively.
Transit Stations:
Transit stations present unique challenges to people who are
print disabled; they must visit specific points along
potentially crowded and complex paths of travel having no signs
which are legible to them, in order to successfully navigate
from street entrances to the proper train. Such a course
involves the challenge of identifying the correct entrance,
change and ticket machines, station agent kiosks, entry gates,
escalators, steps and elevators onto the platform, a specific
platform area and specific train or coach.
Previous research indicates that Talking Signs users
independently learned many characteristics of the system which
we did not specifically teach them in the short training
preceding test trials. Ease of use, learning to scan, ease of
picking up messages, and following the sign to the destination
are thought to be related to the level of training and indicate
a need to evaluate training requirements for effective and safe
use of Talking Signs. The present study, therefore focused on
the question: "What is the minimum amount of training required
for a person to effectively and safely use the Talking Signs
system?" To answer this question, we evaluated the travel
characteristics of 36 visually impaired people who used the
Talking Signs system as an aid to navigation through a complex
subway station in downtown San Francisco (Powell Station) for
the Bay Area Rapid Transit (BART) and the San Francisco
Municipal Railway (Muni). The broad cross section of subjects
was divided into three groups, each group being matched for
varying levels of mobility skills, degree of residual vision,
and method of travel (guide dog or cane), presence of hearing
impairment, and level of spatial thinking. Each group received a
different level of training on the proper use of the system.
From our results it is clear that persons having visual
impairments are readily able to learn to use the Talking Signs
system for the wayfinding information necessary for traveling
routes in a transit station without assistance. Within the
limits of the one hour test period, of 36 participants traveling
routes without aid, 35 successfully completed at least two easy
routes 23 successfully completed at least two medium routes
(plus all easy routes) and 17 successfully completed at least
two hard routes Plus all easy routes and all hard routes). It
appears that training enabled participants who were more highly
trained to complete more complex routes. This finding was not
statistically significant, however. Even the minimal level of
training in which participants received written instructions in
their preferred medium, enabled many participants to
successfully travel routes in a complex transit environment in
which they were given no information other than that available
from the Talking Signs, themselves.
Surface Transit and Buses:
In the absence of Talking Signs transmitters, there are two
primary ways which blind travelers use to find unfamiliar bus
stops. The first is to ask another pedestrian, if one can be
found, and the second is to laboriously look from one end of a
block to the other, bearing in mind that stops may be at the
beginning, middle or end of a block, may or may not be marked by
a pole, may or may not have shelters, and shelters may be along
either the curb side or at the building line away from the curb.
In order to locate a particular bus of many which are parked
along a curb, the blind pedestrian must hurry from one door to
the next, asking the bus driver or waiting passengers the
identity of each bus.
Locating and Identifying Bus Stops: Eighteen blind participants
located and identified bus stops using either the Talking Signs
system plus their usual mobility skills or their conventional
strategies, including tactile signs, but without asking for
assistance. They then located and identified a particular bus
out of three lined up along a curb using either their normal
procedure of asking the driver or using the Talking Signs
system. Participants were generally more successful in locating
and identifying bus stops using the Talking Signs system than
using tactile signs, particularly when the bus stop was
identified only by a pole-mounted sign rather than a bus
shelter. Participants using dog guides had particular difficulty
in the absence of the Talking Signs system.
Identifying Buses en masse: In order to locate a particular bus
of many which are parked along a curb, the blind pedestrian must
hurry from one door to the next, asking the bus driver or
waiting passengers the identity of each bus.
Success on the bus identification task was high regardless of
whether the bus was labeled with the Talking Signs system or
not, with only 9 failures on 108 attempts to locate the correct
bus within one minute. There were also no significant
differences in times to locate the bus using the two methods.
However, subjects thought that because there were no physical
obstacles, either people or newspaper racks interfering with
walking near the edge of the sidewalk directly to the door of
the bus, the experimental set-up for locating buses represented
an unrealistically easy task for the "no Talking Signs"
condition. That is, subjects volunteered that under more
typically challenging conditions, the Talking Signs system would
make identifying and locating buses much easier. There was,
perhaps a statistical "ceiling effect" on this task.
When, during the Focus Group, participants were asked to choose
between labeling bus stops with Talking Signs transmitters and
labeling with tactile signs, all eight participants preferred
the Talking Signs system. The tactile signs were considered
helpful for definite confirmation, however.
Remote infrared audible signage provides wayfinding information
for surface transit as it has previously been shown to do for
transit stations, thereby enhancing independent use of public
transit by persons having visual impairments.
Pedestrian Crossings at Light Controlled Intersections:
Intersection crossing points are the places in any journey where
the traveler is most vulnerable to danger, in the form of
collisions with passing vehicles which can result in serious
injury or death. This significance is widely recognized not only
by blind persons themselves, but >by the Orientation and
Mobility profession, who spend a good deal of their mobility
training time with each client attempting to teach techniques
for successful street crossings. At controlled intersections in
busy urban areas, many confusing cues are presented to the blind
traveler who must rely primarily on traffic sounds to accomplish
the task. For example, the usual cue for determining when it is
safe to cross in this situation is the detection of traffic
beginning to move in the pedestrian's direction of travel and
parallel to him. However, anywhere that green arrows allow turns
in front of the pedestrian, safety is not assured by this cue.
In addition, even for the most experienced traveler, there are
certain things which can not be determined by sound, such as the
exact width of the street or if a turning island exists. Having
access to all of this type of information lowers the risk of
making an inaccurate judgment.
Progress has been made in avoiding many of these ambiguities
through the deployment of prototype Talking Signs units at
signalized intersections in downtown San Francisco. The
application involves providing two types of information to
pedestrians. The first tells the user where he or she is
located; it is comparable to the information posted on the
visual signs at each intersection. The repeating message users
hear from the speakers of their hand-held receivers when they
are walking down the sidewalk is, for example, "Traveling East
on the 800 block of Grove Street toward Larkin Street." When
users nears the curb, another message is heard through the
receiver's speaker. This "pedestrian crosswalk indicator"
message tells users the condition of the traffic signal. It
repeats, for example "Wait... Larkin Street" or "Walk Sign....
Larkin Street," the particular message depending upon the status
of the visual walk/wait sign. Sighted pedestrians also have
specific information about the characteristics of an
intersection such as turn lane, mid-block crossing, cut-through,
island, pedestrian activated 4-way walk signal, free right
turning lane, short walk cycle, use of pedestrian activated
signal at island for walk signal to cross second half of street,
etc. These extended messages which communicate special
attributes about an individual intersection can be added to the
message (following the street name on the approach message).
Alternatively, this additional information may be provided
through a different receiver channel.
In determining the effects of Talking Signs on street crossing
performance at complex signalized intersections, 20 persons
having very little or no vision were asked to cross four complex
signalized intersections in the Civic Center area of San
Francisco under two conditions: with information provided by
Talking Signs, and without information provided by Talking
Signs. All crossings were made under normal daytime traffic
conditions.
Participants completed the experiment individually, in sessions
lasting approximately 90 minutes. Participants received
approximately 10 minutes of training in using Talking Signs at
intersections before completing the experimental procedure.
Results: Binomial (step) tests were conducted in which each
participant was compared with him/her self on each of the above
measures at each of the four intersections, in both the Talking
Sign and no Talking Sign conditions, and then a statistic was
computed to determine the probability that differences between
performances using Talking Signs and no Talking Signs were
significant.
Participants were more successful on eight of the nine measures
when using Talking Signs than when not using Talking Signs.
Nineteen of 20 participants were more successful when using
Talking Signs than when not using Talking Signs. One participant
had the same (nearly perfect) score both with and without
Talking Signs. Participants included persons using both long
canes and dog guides, persons with and without hearing loss,
persons who considered themselves to be good to excellent
travelers, and persons who did not consider themselves to be
good travelers. The following types of data were obtained by the
experimenter as each participant made each crossing.
Safety: Did the participant begin the crossing during the Walk
phase of the light cycle?
  * Talking Signs 99%
  * No Talking Signs 66%
Precision: Did the participant begin the crossing from within
the crosswalk?
  * Talking Signs 97%
  * No Talking Signs 70%
Was the participant heading toward the opposite corner when
he/she began the crossing?
  * Talking Signs 80%
  * No Talking Signs 48%
Did the participant end up within the crosswalk at the opposite
corner?
  * Talking Signs 76%
  * No Talking Signs 56%
Need for assistance: Did the participant need (request)
assistance in finding the crosswalk?
  * Talking Signs 1%
  * No Talking Signs 19%
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