Applied Computer Simulation Labs

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Blind Street Software Guide

for Blind Street Software Version 0.3b


Blind Street provides a virtual training environment that may help persons who are blind to more effectively and safely determine the number of lanes of traffic on a road, the direction of traffic flow, and areas of a road where it may be safe to cross, based on the relative density of flowing traffic. Blind Street is designed to be used with the assistance of an Orientation & Mobility Training Specialist.

Developer Information:

The Blind Street software is developed by the Oregon Research Institute Applied Computer Simulation Labs. Our address and contact information are shown below.

Oregon Research Institute
Applied Computer Simulation Labs
1715 Franklin Blvd.
Eugene, OR 97403-1983

If you have any questions about how to use the Blind Street software, or if you are having trouble getting the software to function, please refer to contact information below:

Email: http://simlabs.ori.org/contact
Phone: 541-484-2123 x2305

Minimum System Requirements:
  • 800 MHz Pentium or compatible processor.
  • 256 MB RAM.
  • 3-D Sound Card (Creative Audigy series recommended).
  • External stereo speakers or headphones (highly recommended).
  • 3-D Graphic Accelerator Card (NVidia FX series or better recommended)
  • 6 MB of disk space are required to install the software.
  • Windows 2000, XP, or Vista.
  • DirectX 8 (or later).

Additional Recommended Hardware:
  • A headphone distribution amplifier such as the Rolls HA43.
  • High quality headphones.
  • An InterSense InterTrax2 head tracker with 3 Degrees-of-Freedom.

Installing the Blind Street Software:

The Blind Street software can be installed by downloading it directly from our web site.

To install Blind Street do the following:

1) Locate the installer application for Blind Street and double-click it. Install Blind Street Icon

2) Click "Next" to install the latest version of the Blind Street software.

Install Wizard Screen

3) The installer will show you a default installation path. Click the "Next" button, if the recommended path is okay.
Install Location

4) You may choose to install a "Desktop" shortcut. Click the "Install" button to install these options. Uncheck any options you do not wish to install.
Install Components Screen

5) You will see this screen when the installation process is complete. Click the "Finish" button.
Install Complete Screen

Updating the Blind Street Software:

If an earlier version of Blind Street is already installed on your machine you will see the dialog window below. Click the "Yes" button.

Uninstall Blind Street Screen

1) Click the "Uninstall" button to uninstall the older version of the Blind Street software.

Uninstall Screen

2) When the uninstall process is complete you will see the following dialog window. Click the "Close" button to complete the removal of the old version of Blind Street.

Uninstall Complete Screen

3) The next time you run the Blind Street installer you should see the following dialog window.

Install Wizard Screen

Using the Blind Street Software:

To start using Blind Street, double-click its icon.

Once Blind Street has started you will see a road with four lanes of traffic, two lanes of traffic moving left, and two lanes of traffic moving right. Various vehicles will pass back and forth periodically and 3-D sounds accompany each vehicle as they move within the training space.

For optimum 3-D spatial realism, both the trainer and student should be wearing stereo headphones, attached to the computer. Alternatively, the student can wear headphones and the trainer can listen to the environment through external speakers. The student should also be wearing a head tracking device (see below), so the computer can determine how to alter the virtual location and dynamics of sound within the simulation.

Hitting the Escape key (Esc) at any time will quit Blind Street.

Blind Street Interface Features

Angle of Listener's Head
- Indicates the angle the listener's head is turned, in degrees, as measured with a head tracking device.

Average Speed of Vehicles - Determines the average speed of traffic flow.

Relative Density of Traffic - Determines the relative density of flowing traffic.

The average speed slider adjusts the speed of traffic from a range of 10 MPH, up to 100 MPH (miles per hour).

Average Speed Slider

The Traffic Amount slider adjusts the average traffic density from a range of 10%, up to 100%.

Traffic Density Slider

Setting Up the Blind Street Audio Hardware:

Hooking Up the Headphone Distribution Amplifier:

The Blind Street software is designed to help students improve their listening skills. For this reason it is important to use an external amplifier with the training system to maximize audio fidelity and have more control of the loudness of the sounds the student hears while using the training system.

A headphone distribution amplifier allows you to send the same audio signal to one or more headphones simultaneously. In addition, each pair of headphones hooked up to the distribution amplifier has an independent volume control, so the loudness can be adjusted for each listener. This is especially useful if you want to hear what the student hears, at a volume that best suits you, while offering complete independent control of the volume the student receives.

Below, are two headphone distribution amplifiers we recommend. One is made by the Rolls corporation, and costs about $70, and the other is available at Radio Shack for about $20.

The Rolls headphone distribution amplifier can be plugged into a standard AC outlet, has individual volume control for up to six pairs of headphones, and can output a louder signal than the Radio Shack unit.

The Radio Shack "3-Channel Headphone Volume Booster" (Part # 33-1109) is smaller and somewhat more portable than the Rolls unit. It requires 2 AA batteries and can handle up to 3 pairs of headphones. There is no individual volume control for each pair of connected headphones, and the amp has less volume output than the Rolls unit.

Either headphone amplifier will work with the Blind Street program. If you need to purchase a distribution amplifier please contact the ORI Applied Computer Simulation Labs and we will tell you where you can purchase one.

The setup for the Rolls headphone distribution amplifier is shown in the image below.

Amplifier Setup

A - This is where you plug the headphone distribution amplifier into the computer's sound card. The computer sound card has several plug "jacks," so you may have to look carefully to make sure you're using the correct one. Often, the jack you'll want to use on the sound card will be the second one from the right as you're facing the machine from the front. If you plug the cable into the wrong jack you won't hurt anything, but you won't hear anything either.

B - The power plug. You should see a bright red light when the amplifier is powered on.

C - Headphone output jacks. You can hook up to four headphones to the Blind Streetsystem at once, if you like. Usually, you'll want just two: one for you, and one for your student. However, it's sometimes useful to hook up two additional guests, so the option is available, provided you have enough headphones. If possible, try to set the volume level of the student's headphones consistently, so their listening experience is as comfortable and conducive to learning as possible.

The setup for the Radio Shack 3-Channel Headphone Volume Booster is shown in the image below.

Headphone Amp Setup

You will need (2) AA batteries for this unit. Below is a diagram to show how the batteries should be installed.

Setting Up the 3-D Head Tracker:

The head tracker is an unusual piece of equipment. On the outside it looks like a thumb-sized piece of plastic, but inside is a very sophisticated, tiny gyroscopic mechanism that can very accurately measure the inertial changes that occur as it is moved in space. The InterSense head tracker provides three-degrees-of-freedom, which means that it can inform the computer of roll, pitch, and yaw, which translate into X,Y,Z coordinate positions that allow the computer to accurately measure changes in position to within thousandths of an inch. The head tracker is key to the Blind Street software as it allows the computer to determine how to "reposition" a sound when the student turns their head, and provides an accurate measurement tool to evaluate the student's listening skills.

The head tracker is mounted with Velcro on a baseball cap. When the baseball cap is placed on the student's head the bill should face backward. This allows the cable to fall behind the student, so it's out of the way, and makes it easy to slip headphones on the student, over the baseball cap. The head tracker needs a serial port on the back of the computer. The plug for the serial port will only fit on one or two of the connectors on the back of the computer, but it doesn't matter which one. It will figure out where it's plugged in automatically. The head tracker must also be plugged into an AC wall outlet, so make sure both the serial cable and the AC connector are hooked up before you use it.

Calibrating the 3-D Head Tracker:

Before you can use the head tracker for training it has to be calibrated. Fortunately, calibration is easy. There's a small round button on the left side of the head tracker that reset it's X,Y,Z positions to zero. This is necessary only when the head tracker is first placed on a student's head. If you don't calibrate the head tracker, the computer won't accurately know where the student's head is pointing. The picture below shows you where the reset/calibration button is located.

Head Tracker Reset Button

Using the 3-D head tracker:

Blind Street was designed to use the InterTrax series of head trackers manufactured by InterSense. The newer versions of the InterTrax have a USB (Universal Serial Bus) connector, which makes them extremely easy to connect since the power is supplied through the same plug as the USB connector. The unit shown above has a USB connector and is about as small as an average person's thumb.

If you have any questions about hooking up your particular model of InterTrax head tracker please do not hesitate to contact us. We recommend the USB model because of its lighter weight and simpler connection.