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The Sonic Glasses Evaluated

The Sonic Glasses Evaluated

The Sonic Glasses Evaluated





Professor Kay, the inventor of the sonic glasses, heads the Department of Electrical Engineering, University of Canterbury, Christchurch, New Zealand.




A precis of the findings from two questionnaires (169 items for the 94 users of the aid, 88 for the 21 trainers) to evaluate the ultrasonic binaural sensory aid for the blind, a mobility and orientation device invented by the author.  The results, summarized in three lengthy tables, indicate that 88 percent of the users found the device useful and that only 20 percent of the trainers thought that their own training was inadequate.


Walter Thornton, in two recent articles (1971a; 1971b), has gone a long way toward informing blind people of the operation and use of the Binaural Sensory Aid for the Blind developed at the University of Canterbury, Christchurch, New Zealand.  Because of the extensive use to which he has subjected the device, he must now be the most experienced user; in consequence, he is also the most able person to say what can be expected from the aid.  One man's opinion, however, is not acceptable when determining a policy to be adopted in relation to the sensory aid; the data presented in this paper, therefore, has been gathered to form the basis for such decisions.  It also gives each person some chance of assessing the value of the aid in his or her setting--an equally important factor.



The evaluation instrument was designed to meet the requirements of a) the blind user, b) the teacher, and c) the agency administrator.  Twenty-five mobility teachers were trained (six in Australia, 18 in the United States, and one in England) to use the device (while blindfolded) in conjunction with the long cane.  Two were dog guide trainers who also learned to combine the use of the glasses with the disciplined handling required by the dog guide.  Each teacher was to train up to eight people over a 12-month period, but various administrative and technical difficulties slowed the program down in most areas.  Only the teacher in England completed his program and, in fact, almost doubled it, training 18 people in the time allotted.  Nevertheless, at the time when the data were collected, over 100 people had been trained with only 10 "drop outs".  The work now reported was completed in June 1972, but further training and evaluation will continue.



The evaluation instrument is discussed in detail elsewhere (Kay, 1972).  In essence it consists of two questionnaires, one designed for the 25 active teachers and one for the blind users.  Some 169 questions are asked of the users and 88 of the trainers.  The answers, therefore, cover the program extensively.  Twenty-one teachers returned their questionnaires; of the 94 sent to blind users in late May, 65 had been returned by the end of June.  One cannot reliably assess the reason for non-returns when using questionnaires, but even sighted participants often fail to provide more than about a 75 percent response.  All questions are in print, so a greater burden was placed upon the blind people.  Where checks can be made on the viability of the data, we find it to be very high.  For example, there were five who said that they had returned their aid; at the time of asking the questions nine had indeed done so.  The proportion of reported malfunctions also checked with the devices received for repair.  There were, in fact, several areas where data checked well.  The details of the questions and answers are to be published in a future issue of the A.F.B. Research Bulletin.  All that can be presented here is a very brief precis of the answers.



Questions were asked on a variety of topics such as trainee characteristics, trainer experience, attitudes to the device, effectiveness of the training program, design and convenience features of the device, skills in mobility for which the device may be particularly suited, etc.  Two particularly relevant areas of interest are mobility skills and attitudes.  The responses are presented in Tables 1,2 and 3.  In Tables 1 and 2 the response of the teachers and the users can be compared; also in Table 1, the long cane user is compared with the dog guide user.  There are significant differences of opinion in some areas, but these should be related to the novelty of the device and the changes it can bring about in blind mobility.  The percentages do not constitute votes of popularity.  Since the opinions of teachers on some skills vary greatly, it is evident that the teaching of these must have influenced the opinions of the users.  The variability also reflects to some extent the inadequacies in teacher training.  Much better training, both of teachers and users, is now possible and this will undoubtedly lead to greater uniformity of opinion.



Several blind users were subsequently asked about the difference in opinion between themselves and the teachers.  It appears that learning continues with usage and a number now find they can do things which were too difficult during training; eg, subtle sounds are now more readily interpreted.  Many teachers are not aware of this because of the lack of good follow-up procedures and inadequate personal experience.  Even those who trained the teachers do not have the experience many blind users now enjoy.  At this point in time, it would appear that some of the blind users could play an important role in future training programs.  (This would be contrary to either the long cane or the dog guide training programs).



Although the results must have been influenced by the many training, technical, and administrative inadequacies, they do show a high level of acceptance by both the teachers and the users, and many new skills have become possible.  The concept of the device has been unanimously accepted by the trainers, and 90 percent of the users believe that it is helpful in mobility.  Eighty-eight percent of the users want to keep the glasses, five percent have not expressed an opinion, and only seven percent have indicated that they do not want to keep them.


Much remains to be done with the device, particularly redesigning to reduce many of its engineering shortcomings.  It was, of course, an evaluation device and limited engineering resource were made available prior to undertaking the exercise (a chicken-and-egg problem); even so, 60 percent of the users thought the glasses adequate in their present form and 85 percent were satisfied with their reliability.



On the question of teacher training, 70 percent of the teachers would have liked more training although only 20 percent felt that their initial training was inadequate.  A greatly improved training program is now possible, but resources for its design have yet to be made available.  Several blind users could perhaps now play a useful part in the training programs in conjunction with the orientation and mobility teacher; they better understand the language of the aid and the perception of the environment which it makes possible.



Kay, L: Sonic glasses for the blind: A progress report. A.F.B. Research Bulletin, 1972, No. 25, in press.

Thornton, W. The binaural sensor, The New Beacon. 1971,


Thornton, W. The binaural sensor as a mobility aid. New Outlook for the Blind, 1971, 65,324-326.(b)