years later they would be able to do—but it was not possible at the time. VOTEM was an example of reducing the requirements to match what was possible. Clearly, spoken Morse code was not a viable input method for someone who could use a typewriter keyboard, but was a candidate for someone who could not. This situation is still the case: speech recognition is only really viable in situations where it is not possible or inconvenient to use a keyboard.
VOTEM—the Voice Operated Typewriter Employing Morse Code sparked my interest in developing technology to assist people with disabilities. It also introduced me to technologically assisted human-human communication. The knowledge and background I had gained in my research into Automatic Speech Recognition showed me that speech communication is very much more than the words which are spoken. Human communication is the very basis of our humanity and is a very complex and subtle process. Our communication with other human beings is not just a set of messages that we relay to other people: it is, in a very real way, our personality. If we are to develop artificial means to replace speech, we must be as concerned about the form of the communication as the efficiency of it as a message carrier.
I thus embarked on background reading in the area of what was to become known as Augmentative and Alternative Communication (AAC)—technology to support people with impaired speech and language. I also became familiar with a range of (relatively unrelated) research topics that would prove to be very useful in my future research.
At this time, Possum Controls was one of the leading developers of systems for severely paralyzed people, these were based essentially on scanning a matrix by sucking and blowing down a tube. Figure 2.1 shows an early version of such a system. This technology had been developed by Reg Mailing, who was a “visitor” at Stoke Manderville Hospital. He observed patients using a whistle to communicate with people. At that time even simple electronics was too expensive for this application, but he realized that the Strowger equipment (a two-dimensional mechanical selector mechanism used in telephone exchanges at time) was inexpensive, and could be modified to provide a scanning matrix which could control domestic equipment or an electric typewriter via a pneumatic tube. He formed the POSSUM Company [Mailing and Clarkson, 1963, Mailing, R., 1968], which in the early 21st Century is still marketing communication aids for disabled people.
By the early 1970s, a number of similar systems had begun to appear [Copeland, K., 1974, Foulds et al., 1975, Ridgeway and Mears, 1985, Vanderheiden, G., 2002]. Some examples of these are shown in Figure 2.2. There were no portable systems, and they all required the disabled person and the conversational partner to look at a remote display or printout. This meant that eye contact, and the ability to notice facial expression, which I believe is very important in face-to-face communication, was not possible. In addition, I thought that an AAC system should be instantly available—so that users did not feel that they had to wait for something important to say, before switching their system on, and that, like speech, it should provide a transitory communication—not a “permanent” written one. An example of the dangers of a printed output was related to me by Arlene Kraat. A non-speaking patient had printed out the message “you did not brush my hair properly” to a nurse, but, instead of this being interpreted as a relatively unimportant comment, it was taken as a formal complaint. This example highlights the difference between the impact of spoken and written messages, which also became a concern in our research into television sub-titling.
Figure 2.1: An early Possum system.
2.2 THE TALKING BROOCH—A COMMUNICATION AID FOR NON-SPEAKING PEOPLE
A challenge for AAC systems was to create a portable device that was mounted near to the face. Conventional displays were not appropriate as visual displays at that time were heavy, large, and expensive. My “eureka” moment occurred whilst I was travelling through King’s Cross station where there was a rolling newscaster display, and I remembered Taenzer’s [1970] work aimed at improving the “Opticon”. This was a reading aid for the blind, in which the operator scanned a printed page via an array of small vibrators on their finger.
Taenzer had shown that a rolling display of only one character width was readable. In a preliminary experiment we showed that the reading speed increased as the number of characters displayed increased [Newell et al., 1975]. We thus conducted formal reading experiments using a simulated display between 1 and 12 characters long. We also compared rolling and walking displays (where the location of the character matrixes were fixed and the letters jumped from one matrix to the next). Users performed significantly better with the rolling display and, with a 5-character display, 99% of sentences could be read at a (fast typing) rate of 60 wpm [Newell and Brumfitt, 1979b].
Figure 2.2: Early AAC Devices. (a) Portaprinter - commercially available; (b) TIC - developed by Rick Foulds, Tufts University, Boston; (c) AutoCom - developed by Greg Vanderheiden, University of Wisconsin-Maddison.
Although a rolling display would be more expensive to produce, we decided that this was essential, and, as a compromise between cost and readability, we built a 5-character prototype using individual light-emitting diodes. This can been seen in Figure 2.3(a). A later version shown in Figure 2.3(b) used light emitting diode array. The whole system consisted of the display mounted in a breast pocket, a battery pack and a keyboard. This fulfilled the requirements I had laid down, and an indication of the success of the Talking Brooch idea was given by a child’s parent who said that the very first time he had told a joke was via his Talking Brooch.
Figure 2.3: The Talking Brooch. (a) A prototype Talking Brooch; (b) the commercially available Talking Brooch.
A portable device the ELKOMI 2 marketed by Diode (Amsterdam) had a 9-letter walking display, but, even though the display was longer, our results would indicate that it would be less easy to read at normal typing speeds.
At much the same time Toby Churchill of Toby Churchill Ltd had developed the Lightwriter, which consisted of a much longer single line display integrated with a keyboard [Lowe et al., 1974], and is shown in Figure 2.4(a). In later versions of the Lightwriter, such as that shown in Figure 2.4(b), there is a two-sided display—one side facing the communication partner, and another identical display facing the operator—again with an integrated keyboard. Although the Lightwriter was not as good at promoting eye contact, it did facilitate an appropriate body language for face-to-face communication. In addition, the integrated nature of the system meant that there was only one “box”, and no external wiring. The only other portable device available at that time was the Cannon Communicator, which essentially was similar in style to a pocket calculator, but with an alphanumeric keyboard and a strip printer.
Figure 2.4: The Lightwriter. (a) Earliest version; (b) 2010 version.
In 1976, Vanderheiden [1976] reviewed the literature in this field, addressing the issues of accessing communication aids and the relative merits of direct selection (as employed in
