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Section 4: Teaching students to determine when there is a crossable gap in traffic

Page 1:Skills needed to determine when it's "clear to cross"
Page 2:USING HEARING -- Know what to listen for and "tune in" to the sounds
Page 3:USING HEARING to determine when it's quiet enough to be "all clear" -- is this skill necessary?
Page 4:USING HEARING -- Teaching students to determine when it's "quiet enough," and understand the effect of masking sounds
Page 5:USING VISION -- Visual tasks for crossing streets
Page 6:USING VISION for "all clear:" Knowing what to look for, and seeing them efficiently/reliably
Page 7:USING VISION for "all clear:" Looking left/right -- challenges and strategies with different eye conditions
Page 8:USING VISION for "all clear:" Procedure to train students to look for vehicles while scanning / glancing to each side
Page 9:USING VISION -- When you see traffic at a distance -- do you have time to cross?
Page 10:USING VISION -- is traffic far/slow enough? "Determining Gaps in Approaching Traffic" (was "TMASD")
Page 11:USING VISION -- How to determine how many seconds is "X" seconds?
Page 12:USING VISION -- ALTERNATIVE when you cannot judge whether the traffic is far/slow enough to allow you time to cross
Page 13:USING VISION -- Determine when the traffic is far/slow enough by SCANNING or GLANCING left/right
Page14:USING HEARING OR VISION -- Which is better to determine when it is clear to cross?
Page15:USING HEARING OR VISION -- Teaching students to choose vision or hearing to detect vehicles

Page16:Review

Please note that the links inserted throughout the text are NOT necessary,

they are meant only for those who want to know more.

Section 4:
Teaching students to determine when there is a crossable gap in traffic

So far, we have talked about:

·  what is a Situation of Uncertainty and how to recognize it(Section 1);

·  teaching students to recognize Situations of Uncertainty(Section 2);and

·  what to do when you are in a Situation of Uncertainty(Section 3).

You'll be pleased to know that this section (Section 4) is NOT about Situations of Uncertainty!
It is about teaching students what to do when they are inSITUATIONS OF CONFIDENCE.

What do we do at crossings in a Situation of Confidence?

Well, since being in a Situation of Confidence means that we can hear and/or see the traffic well enough to figure out when there is a crossable gap in traffic, we go ahead and cross when there is a crossable gap, of course!
But wait -- that's assuming thatwe KNOWhow to figure outwhen there is a crossable gap in traffic!
And THAT is what this Section is all about -- teaching students how to use their hearing and/or vision to figure out when there's a crossable gap in traffic at Situations of Confidence.
We will cover each of the following forcrossing in Situations of Confidence:

Determining when it is "clear to cross"

·  Using hearing;

·  Using vision (looking from side to side);

Determining when there is a crossable gap in traffic that you can see approaching (knowing it is slow/far enough to allow you time to cross);

·  Learning to make that determination whenlooking from side to side;

For students who haveboth functional vision and hearing:

·  Understand the advantages and disadvantages of each and how to use them;

·  Be able to choose which is best for each situation.

This sums up all that is covered in this Section. As you read each page, please remember these are strategies only to be used when you are in Situations of Confidence. Enjoy!

Page 1 of 16

Skills needed to determine when it is "clear to cross"
if you are in a Situation of Confidence

Using hearingyou need to:

·  know what to listen for and be able to "tune in" to those sounds;

·  be able to determine when it is quiet enough to be "all clear" (understand the effect of masking sounds)

using visionyou need to:

·  know what to look for and how to see it effectively and reliably;

·  be able to determine it is "all clear" by scanning / glancing left/right efficiently

If you can see traffic at a distanceyou can determine whether you still have time to cross if you can:

·  determine if the time-to-arrival of the approaching traffic is long enough to cross and

·  make this determination by glancing / scanning to each side.

If you have usable vision and hearing, you need to understand:

·  what are the advantages / disadvantages of each, and

·  when to use which.

Teaching these skills is what this section is all about!

Page 2 of 16

USING HEARING
to determine when it is "clear to cross"

Know what to listen for and "tune in" to those sounds

Students can greatly improve their ability to hear approaching vehicles with experience -- asDaniel Kishsays, people develop a knack for it when they listen intently on a regular basis. For example, at my street-crossing workshops I've noticed that those who regularly listen for traffic to cross streets can hear the approaching vehicles much sooner than those who do not.
Suggestions:

·  Have the student listen for approaching traffic, and record the detection-to-arrival times of the vehicles that are heard when it is quiet. After listening intently for a while, the times of detection-to-arrival will probably get longer as the student learns to "tune into" the sound of the approaching traffic.

·  Daniel Kish suggests that turning the head periodically can greatly improve the detection of minute sounds, especially against a noisy background such as wind or other traffic sounds. Perhaps the reason this is effective is because it shifts or refreshes the sound, which attracts the brain's attention to it.

·  Daniel Kish also suggests stepping back or forward, listening to find the best position to hear the vehicles -- this may also avoid or reduce any blocking of the sound of the vehicles.

Page 3 of 16

USING HEARING
to determine when it is "clear to cross"

Be able to determine when it is quiet enough to be "all clear" (understand the effect of masking sounds)
Is this skill really necessary?
The importance of understanding the effect of masking sounds hit me like a ton of bricks when I went back to analyze the crossing whereSue Etterswas hit. I had assumed that Sue had been crossing in a Situation of Uncertainty because she said she crossed only when it was quiet, and yet she was often surprised by vehicles that she hadn't heard when she started crossing.
When I was finally able to assess the situation, I was shocked to find that it was NOT a Situation of Uncertainty, even when the road was dry and it was 4:00 in the afternoon (when thesound level of "quiet"is usually highest)!
So what's going on here? If this was not a Situation of Uncertainty, why was Sue often surprised and eventually hit by a car she hadn't heard when she started crossing?
Well, to make a long story short, I found out that when Sue thought it was "quiet," there were actually still some masking sounds from receding cars. And I had noticed that her crossing was one ofthose placesthat I told you about, where even the slightest masking sound, such as receding cars after they were out of sight, or a train in the distance, kept me from hearing vehicles with enough warning.
So Sue didn't realize how quiet it had to be. She hadn't noticed that the sound of the distant cars made her unable to hear the sound of the approaching cars until it was too late.
That is why it's important for your students to understand the effect of masking sounds and, in situations where they can be confident that "it's clear to cross when quiet," they need to know how quiet it has to be in order for that strategy to be effective!

Page 4 of 16

USING HEARING
to determine when it is "clear to cross"

Teaching students to determine when it is "quiet enough," and understand the effect of masking sounds
Students need to be able to . . .

·  NOTICE masking sounds (sounds that are not part of theambient residual sound) and

·  EVALUATE THE EFFECT of those masking sounds on their ability to hear approaching vehicles.

Noticing masking sounds

One strategy that may help is to ask the students to indicate when they think it is "quiet" (or as quiet as it can be in that situation!). If they are reporting that it is "quiet" when there are actually some masking sounds (such as receding vehicles, distant lawnmowers or airplanes, etc.) help them learn to notice those sounds.
They may not report some sounds because they think the sounds are not loud enough to cause a problem, and they may be right! But you want to be sure they at least NOTICE the presence of those sounds. Learning whether those sounds make a difference is the next step.

Learning the effect of various masking sounds in different situations on the ability to hear approaching vehicles.

As we've explained in Section 1, a little masking sound usually isn't a problem, but sometimeseven the slightest soundscan drastically reduce the ability to hear approaching vehicles. Students can learn about the effects of masking sounds by observation, either formal or informal as described below:
Informal observations:

·  When students can hear a car coming from a distance, have them notice that they can't hear cars coming behind it (or sometimes cars coming from the other direction) until after the first car has passed. Make sure they understand that this is because the sound of the first carmaskedthe sound of the second car.

·  When students are measuring the detection-to-arrival times of approaching vehicles, have them notice how much shorter those times can sometimes be when there is another sound such as an airplane or receding car.

Formal observation:

You can help students learn to judge when masking sounds are loud enough to significantly impact their ability to hear approaching vehicles by creating steady masking sounds and letting them observe what happens:

Step 1:Find a situation where the student can hear approaching vehicles with enough warning to know that it is clear to crosswhen quiet.
Step 2:Create a steady masking sound (I use a recording of my vacuum cleaner!) and ask the student if he can still hear the vehicles well enough. Make sure the source of the masking sound (such as the tape recorder) stays in the same place and remains steady throughout this process.
Step 3:Use theTMADmeasurements to assess whether the student was correct about being able to hear the approaching vehicles above the masking sound with enough warning.

For example, perhaps a student judges that in a certain situation she can hear the vehicles with enough warning to know that it's clear to cross whenever it is quiet, and the TMAD measurements indicate that her assessment was correct. You then can play a recorded steady noise softly and ask the student to judge whether she can still hear the traffic well enough above the noise, while you measure detection-to-arrival time to give her feedback. Sometimes I ask students to set the volume of the recorded noise themselves, making it just low enough that they think they can still hear the vehicles over that masking sound, and then we use the TMAD to see if the masking sound was loud enough to impact the warning time.

Page 5 of 16

USING VISION
to determine when it is "clear to cross"

Visual tasks for crossing streets
So far, we've talked aboutlisteningfor vehicles to identify when it's clear to cross. Now we're going to consider the task oflookingfor vehicles to determine if there is a gap in traffic long enough to cross.
Basically, there are two visual tasks for crossing streetsIFyou are in aSituation of Confidence:

1. Watch for "all clear:"
This task involves looking to make sure nothing is coming.

2. Determine if gaps in traffic are long enough:
Students who can see vehicles approaching in the distance may be able to determine whether those vehicles are far/slow enough to allow time to cross before they arrive.
Assessment and training of this skill may be just as important as the skill of making sure it's "clear to cross." Lack of this skill may be what caused the deaths of Dick and Lorraine Evensenat the crossing shown in the photo to the left, and research suggests that some people with visual impairments think that their ability to judge gaps in traffic is better than it actually is (Cheong, Geruschat, and Congdon, 2008).

But WAIT! There's MORE -- and it's critically important!

Glancing or scanning in each direction:
Unlikelisteningfor vehicles, which can be done from both directions at once, people canlookfor vehicles in only one direction at a time (unless they have two heads like the woman in the photo!).
This means that both of the visual street-crossing tasks(watching for "all clear;"anddetermining ifgaps in traffic are long enough)must be done while looking from side to side to make sure there is a crossable gap inbothdirections.

This will all be covered on the next few pages, starting with learning how to look for vehicles effectively.

Cheong, A.M., Geruschat, D.R., Congdon, N. (2008). "Traffic gap judgment in people with significant peripheral field loss."Optometry and Vision Science, American Academy of Optometry. Vol 85, No 1: pp. 26-36

Page 6 of 16

USING VISION
to determine when it is "clear to cross"

Knowing what to look for, and how to see all vehicles effectively and reliably

Just as students who use their hearing need to learn how that hearing is affected by conditions such as ambient sound level, blockage and masking of sounds, and clogged ears or head congestion, students who use vision to watch for vehicles need to understand how lighting, sight lines, and features of vehicles can affect their ability to see them.
For example, they may notice that