This project started out with a single primary goal, to build an aide that would enable the client to express his thoughts in intelligible speech. There were numerous secondary goals:
In the course of building this device we learned a lot, and managed to come up with an aide that met not only the primary goal of communication, but also all of our secondary goals:
Building the device so that the client could operate it efficiently involved looking at the client’s capabilities and trying to take full advantage of them. We had learned that Michael was quite capable of operating 8 large buttons, especially if they were spaced fairly far apart. We learned that his fine-motor control problems extended into the realm of not being able to control pressure being applied. Thus our eight buttons needed to be sensitive to light pressure as well as being able to withstand abuse. For these reasons we decided to use buttons from video games, as they are both sensitive and durable by necessity of their market. We also installed a large, durable, lever arm, on-off switch. This was chosen because it enabled the client to easily turn the machine on and off, and because it used a different movement type (a swing instead of a press) which doesn’t detract from his ability to operate the buttons.
To provide feedback to the client we took advantage of the fact that he can read and we hooked up an LCD to the parallel port. We then divided the screen up into several sections, corresponding to the most useful information to the client at that particular point. We angled the screen so that it would be aimed at the client's head when he is sitting in his wheelchair, and we avoided scrolling. We also gave the facilitator the ability to independently select the text to be displayed on the LCD from the words that are programmed to be said.
To be comfortable for the people conversing with the client the project needed to provide natural sounding speech at natural speeds. We accomplished this by a combination of digitized human speech and a good speech synthesizer. The speech must also must occur at natural speeds, which means that there cannot be any significant delays between selection and execution of speech items and that the selection process must be fast for the client. We did this by using a combination of hardware appropriate for a real-time environment and efficient software coding. In an effort to keep maximum flexibility and to ensure minimal key presses we adopted a two phase approach, Quick Keys for the most common needs and Infinite Lists for everything else.
The ease of use was provided by having all of the needed information visible to the client or facilitator when they needed it and by keeping the whole system as simple as possible without sacrificing power. For the client this meant having text describing his current options displayed in a manner corresponding to the buttons. For the facilitators this meant having a friendly window-based environment as show in Figure 7-Figure 12.
Flexibility was achieved by the use of a building function applied to lists of letters/words/phrases. This means the client is able to put items together from the lists to form new items and because one of the lists is all letters, he can build any word(s) or phrase he wants. The client is able to save these built-up words or phrases means that he can personalize the system to his own conversational styling.
The project was kept affordable by using or modifying existing technology to our purposes. We started with a computer that had the sound and the input capabilities we needed at a price we could afford. The computer needed to be portable so we made it so it can run off batteries and has a built-in display and sound. The finished size was 14" wide x 14" long x 1-5" deep with a total weight of 23 pounds. It is constructed out of 3/4" plywood and everything is strapped down to insure durability. When completed the project cost was under $800, including the parts that were destroyed or scrapped because better parts were found. To build another similarly configured system would cost somewhere around $450.
In the process of building this system we consulted with a large number of experts in the field. These included Easter Seals of Colorado, Denver Children’s Hospital, the Speech Pathology Department of the University of Wyoming, the Speech Pathology group from Laramie Public Schools, the Developmental Preschool - Laramie, Wyoming, Educational Resources at Laramie County Community College - Cheyenne, Wyoming, and the parents of three children with severe speech impairment. We showed them our work in progress to get their feedback, which was very favorable and which has caused us to investigate further marketing of the product.
The client has now had the device for 4 months and we are told that he likes it very much and uses it daily. The family has told us that it is truly wonderful and they greatly appreciate that we built it for him. His speech therapist is very impressed with the device and has inquired about securing another such device for one of her other clients. We did get one bit of negative feedback, which concerned glue we used to secure the 2" keycaps on the buttons not holding up for extended periods of time.
We have been reluctant to do any real advertising of the device until we had a chance to review the system we built, but word has started to get out and demand for additional systems has started coming in. We have built a second system for a child, in Laramie, who has fine-motor control. His system uses the full keyboard in a combinative manner. His preschool teachers have given us great feedback and have hinted that there is another child in the school who could use a device similar to the one described in this discussion. Additionally, there are three other requests for systems; two more for the original family (they have two adopted 4 year olds who also cannot speak), and one for a young woman in Oklahoma.
Our systems are useful for literate speech disabled person’s with some method of manipulating buttons or sensors. This represent 3%-6% of the non-speaking population [KB93] and represents about 40-80 cases per year at Easter Seals of Colorado. Future research can be conducted in many aspect to improve either the systems performance, or the number of people that it is useful to, including:
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