"You know how to whistle don't you? Just put your lips together and blow." Few user manuals could be condensed into this single if much abused line from a Bogart movie. But for John Prestwich, a well-timed whistle is all he needs to direct his Possum. This is just one example of his innovative approach to using environmental control and other aids to living such as voice-input word processing. But then, what else would one expect from someone acclaimed "Man of the Year" in 1991. John contracted polio in 1955 at the age of 17. As a result of this he is paralysed below the level of his chin. Conventional methods for using computers are not available to him. Even those means which have been especially designed for people with physical disabilities, such as light pointers or single switch operation, are not appropriate.
If asked which technological development would make the greatest impact on his life John unhesitatingly replies "voice controlled robotics". Yet, for John, both whistling and speaking must be synchronised to the imposed rhythm of his artificial respirator. John relies upon the negative pressure respirator for his breathing. John's chest is encased in a rigid shell with a gap for chest expansion. The machine creates and releases a partial vacuum by which means his lungs are forced to inspire and expire air (315 million times and increasing: one of the reasons for his long-standing entry in the Guinness Book of Records).
Over the years John has so adapted himself to this regimen that his sense of timing is impeccable. He rarely misses a menu selection nor is he interrupted even mid sentence by lack of breath.
The few occasions on which this control breaks down are due to respiratory infections or indigestion! Many of us will have eaten injudiciously over the recent holiday season, and unfastened our waistbands to accommodate the temporary swelling. John has no diaphragm; if his stomach bloats and pushes upwards, then the gap for chest expansion decreases, reducing the volume and efficiency of his breathing. This adversely affects his capacity for whistling and speaking, and disrupts his timing. There are some computer-human interface problems in the real world which are never dreamed of in R&D laboratories.
Although he favours using a whistle to control the Possum (because he finds there is less interference from TV or CD) John is an enthusiastic user of speech-recognition technology. John has good voice quality but because he is softly-spoken, the initialisation of his system was more extensive and tiring than it might be for other users. It took him 3-5 repetitions of each item and command word to train the system to his voice. John employs voice control for information access and word-processing amongst other uses.
Whereas previously John might have asked his wife Maggie to locate and dial a telephone number for him, or to take a letter from his dictation, he now has independent access to these facilities.
If John wishes to contact somebody, he selects his on-line telephone directory from a menu screen, and when the directory is open, uses the phonetic alphabet to indicate the appropriate subset, saying "tango" to display the list of names beginning with `t' for instance. When the names are listed he says the appropriate
name, and the number he requested is printed on-screen in large characters.
John has to switch from the voice controlled PC to the whistle-obedient Possum to dial his call. Selecting the dialler from the Possum, John is presented with a menu of commands and numbers from 0 to 9. The menu items are sequentially scanned, and John whistle toggles as the appropriate number lights up. In this way he builds up the telephone number and then whistles the command to dial.
Observing this roundabout procedure, the casual visitor may be tempted to shortcut this by offering to place the call, but to John, his independence in such matters is "a big thing" : In John's observation and experience, misplaced `kindness' can exacerbate the isolation of some disabled people, excluding them from active management of their own affairs. He says that the real danger arising from this is that the only means of contact such people have with others is to make a request prefaced with "Could you".
John is determined to limit his requests to only those things which he absolutely can not do for himself, and as it is, he is working on those. Having glimpsed some of the campaigning letters he has composed, one can only assume that John's family motto is "No quarter asked nor given". In words reminiscent of Carlyle's classic phrase "Little other than a red tape Talking-machine, and unhappy Bag of Parliamentary Eloquence", John makes full use of his speech-to-text facilities to lambaste bureaucratic short-sightedness, and to express his robust opinions.
John says that his quality of living received a inestimable boost with his marriage to Maggie in 1971 _ When assessing the contribution that technology has made to his life, John reports it thus: "When I first became disabled there was nothing to .assist me. I couldn't even switch an alarm bell on. I had no movement at all. Now, technology has caught up with my disability and I'm able to have full control of my environment, and to speak to the world with
out help from anyone." Anybody who has met John is tempted to follow the word "disability" with "and rugged determination". Yet there is no hint of complacency or satisfaction with the technical status quo. The much prophesied telecommunications revolution will bring more information and power to John than ever before-the next few years can only be interesting.