3D-Sound Station

Designers: Jonathan Weiss, George Crowell, Mike Chu
Client Coordinator:  Luanne Holland and Susan Parker, Durham Public Schools
Supervising Professors: Richard Goldberg and Kevin Caves

The client was a ten year-old boy with multiple disabilities, causing limited vision and cognitive and developmental delays.  The goal of the project was to provide a versatile stimulation and entertainment system, activated by switch presses.  The 3D Sound Station includes speakers, large pushbutton switches, an LED tube, music keyboard, and an mp3 player, all mounted on an adjustable stand.  Several modes, selectable by the therapist, allow the station to provide different types of cognitive training and feedback for the client.

How this project helped
The client is often unable to independently participate in class activities and has had limited success with commercially available technologies. The 3D-Sound Station will aid in therapy with the client, as well as provide him with entertainment.  The client was intrigued by the device from his first interactions.  Our supervisor, the client’s speech therapist, said,  “The device looks great and [the client] seems to enjoy it already.”

The 3D Sound Station (Figure 1) includes five main components: an mp3 player, speakers, user input switches, LED tube, and detachable musical keyboard.  In addition, a teacher interface box allows the teacher to switch between different operating modes of the device.  The mp3 player (Rogue Robotics, Toronto, Ontario) is controlled via RS232 serial commands from a PIC microcontroller. Because it uses an SD flash card, the audio files can easily be updated by the client’s teachers, using any computer.

Four powered speakers provide audio feedback; one pair acts as the left channel, and the other pair acts as the right.  The two high-contrast interactive switches (Enabling Devices, Hastings-on-Hudson, NY) provide light and vibration feedback when pressed.  The LED tube (purchased at crazypc.com) provides bright colorful light for visual feedback, as well as encouragement for the client to look up and sit up straight.  The musical keyboard (purchased at Radio Shack) connects directly to the speakers via a headphone jack.

The 3-D Sound Station has six operating modes.  The first three modes are programmed to teach the user cause and effect.  Mode 1 outputs the same auditory reward upon activation regardless of which switch is pressed, while Mode 2 outputs a different reward sound for the left and right switches.  Mode 3 chooses a random song from Folder A when the left switch is activated, and chooses a different random song from Folder B when the right switch is activated. Currently, Folder A contains music files while Folder B contains voice clips of our client’s father.  However, these folders can be reprogrammed to contain any desired audio files.

Mode 4 encourages the user to follow directional auditory cues.  A five second sample of a file randomly selected from Folder A is played out of the left speakers only, and consequently, a five second sample of a file randomly selected from Folder B is played out of the right speakers only.  The user then is then allowed ten seconds to choose by activating the respective switch.  Once selected, the file is played through all four speakers. This mode stimulates a cognitive response from the user and allows him to make decisions. Mode 5 can be programmed to allow the client to respond to simple questions.  Currently, pressing the left switch produces a recorded “No”, while the right switch produces “Yes”.

The first five modes can be programmed via the teacher interface, which uses two 6-position knobs, to determine how long the audio response will play: 5, 15, 30, and 60 seconds, momentary, and full-length.  In all five modes, the LED tube lights during the audio response.

In Mode 6, the switches are deactivated and a musical keyboard, which has been placed on the tabletop by a teacher, is powered on. The keyboard sounds play through the four speakers of the device.

The components are mounted to a sturdy music stand, to which a sheet of polycarbonate is attached.  The music stand allows for adjustment in both height and tilt angle.  A wooden disk, attached to the bottom of the stand, provides good stability.  A PIC16F876 controls the system, and power is supplied by a 16V, 500 mA wall transformer.

Cost of parts for the 3D Sound Station was about $520.

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