Forum Proceedings

Charles A. Laszlo, Ph.D.

Professor Emeritus
Department of Electrical and Computer Engineeringbr University of British Columbia

Chairman Assistive Listening Device Systems (ALDS) Incorporated

The proper way to look at the classification of assistive listening device technologies.

At the Forum we have examined existing assistive listening devices divided into FM, infrared and loop categories.  I wish to submit that such a categorization is based on only one aspect of assistive device technologies, and that due to the shortage of time we did not have the opportunity to fully synthesize our views on  the "common" problems.

The main purpose of assistive listening devices is to deliver "clear speech". Clear speech may be defined as speech delivered to the hard of hearing listener from the speaker's mouth, or from a TV or other sound system, without any distortion by echoes, corruption by noise, or modification by acoustical conditions. The general scheme for all assistive listening devices is shown in the attached diagram.(Diagram 1)

As illustrated, the existing technologies (FM, infrared, inductive) differ only in the method by which the signal is transmitted non-acoustically. They all share the common components required to convert the acoustical signal to a high-quality electrical signal, and on the other end, to deliver the signal in the most appropriate form to the hard of hearing listener.

Any analysis or comparison of the different technologies available today, and the evaluation of technologies that may become available in the future, must be considered in this general framework.  Some problems, such as microphone arrangements and signal acquisition are common to all system, while other matters, such as privacy, depend on the transmission method (FM, infrared, inductive) used.

It became apparent at the verbal presentation of the summary reports at the Forum, that this essential distinction was somewhat lost. For example, specific recommendations were made for improved microphone arrangements for FM systems, but not for infrared or loop systems. Yet, the microphone issue is common for all system, whatever transmission methods they may use.

I would recommend that in the preparation of the final report the common issues, and the issues specific to each of the transmission methods, be clearly separated. The scheme illustrated provides the correct framework for presenting the existing obstacles and the technological needs in this area.

A view on accessibility for hard of hearing people

A major concern of people with disabilities is accessibility, but this term has different meaning to people with different disabilities. For example, people in wheelchairs are concerned with mechanical accessibility to places and services so that they can get access to buildings, enter rooms, use bathrooms, reach telephones, and so on. Hard of hearing people define accessibility in terms of their ability to communicate and to understand verbal communication. In this context signs and written instructions, quiet acoustical surroundings, good lighting to aid speech reading, and assistive listening devices are important.

In the US and Canada the fight for such hearing or communication accessibility has been a major focus for hard of hearing people, and some spectacular results have been achieved.  For example, and we now have laws that require telephones to be hearing aid compatible. Such laws have a profound impact. Hard of hearing people can now reasonable expect that eventually all telephones will be accessible to them. The responsibility to provide such telephones is not the responsibility of the individual hard of hearing person; he or she has to do nothing. The responsibility has been passed on to the manufacturers and suppliers of telephones to ensure that hearing aid compatibility exists. Naturally, the hard of hearing person still has the responsibility to obtain a suitable hearing aid equipped with a T-switch in order to take advantage of the capabilities of hearing aid compatible telephones. If the hard of hearing person decides to use a hearing aid without the T-switch, then we expect that he or she is prepared to bear the consequences.

The decision to introduce laws that require that public utilities supply the means of access through the hearing aid compatible telephone is an act by society to provide the means of communication for hard of hearing people. It seems to be obvious that such societal action with respect to telephone accessibility cannot succeed without hard of hearing people taking the responsibility to ensure that they take advantage of what is made available to them. In other words, they must decide to purchase the right kind of hearing aid.

Another major aspect of accessibility for hard of hearing people is the ability to hear, communicate, and participate in those aspects of life where live speech, verbal presentation, face-to-face communication, and interaction are essential. Unfortunately, in many everyday environments it is difficult, and often impossible, for hard of hearing people to communicate effectively. For this reason hard of hearing consumer organizations are exerting a great deal of pressure on governments, schools, churches, health care institutions, entertainment facilities, and on businesses to provide hearing-accessible environments.

Among the factors that help to create such accessible environments the acoustics of rooms is obviously very important. The creation of good acoustical environments is difficult, but nevertheless it should be a major concern in the architectural and engineering design of buildings. Not much can be expected in the improvement of existing buildings, and so in general we must continue to cope with generally poor acoustical environments.

This is one of the reasons why assistive listening devices and systems are gaining popularity. Specifically, under certain circumstances, such devices can overcome the barriers created by poor acoustical conditions. Thus, the demand for better accessibility is closely linked to the performance and availability of assistive listening devices. It is significant that at present the tendency is to judge accessibility in terms of what facilities are provided by others. For example, we consider a movie theatre or similar public place hearing-accessible if a suitable infrared, FM, or loop system is provided.

In general, hard of hearing people expect that accessible public places provide both the transmitters and the receivers for infrared and FM systems. From the provider's point of view, making available the transmitter part of the system requires a one-time installation. For example, to set up the equipment for the transmitting part of an infrared system in a meeting hall, it is necessary to install a bank of microphones, a microphone selector, an amplifier, and the infrared panels, and to establish cable connections to all these parts. The financial investment in such a system may be quite substantial. However, microphones and other components of the system often exist as part of the public address system, and so costs can be kept within reasonable limits. The important point is that the provider has to be concerned about the system only once. They have to make a capital investment, and apart from some occasional maintenance, have very little to do with the transmitting part of the system afterwards.

The receiver part, however, is another matter. To make these available requires a substantial on-going operational effort. To use our example of the infrared system, the operator of the meeting hall must ensure that there are a sufficient number of receivers, neck loops, silhouettes, and earphones available. The operator must also have staff to ensure that the batteries are charged and that the receivers are working well, that the receivers are handed out and collected(!) after use, that their operation is explained to hard of hearing people, and that assistance is given to those who run into trouble with the equipment. To ensure that all is running smoothly requires careful organization and specially trained people. This is very costly and troublesome for most operators.

Not surprisingly, experience has shown that while institutions are prepared to supply the installations that involve the transmitting equipment, many are reluctant to commit themselves to the related facilities and personnel required by the operational management of the receivers.

It is not difficult to appreciate the problem. Hard of hearing people are often frustrated by not being able to use an assistive listening device which has been provided for them. They commonly encounter inoperative receivers, discharged batteries, unfamiliar equipment, and lack of help! Thus, hard of hearing people feel that the many institutions and commercial establishments are insensitive and are not interested in providing proper accessibility, while on the other hand, management of facilities often conclude that hard of hearing people are not appreciative of their efforts and make unreasonable demands. Stories of unhappy experiences of operators are abound, and these negatively influence the motivation of managers to install systems for hard of hearing people. It is truly a sad situation when goodwill and effort results in frustration and bad feelings on both sides!

In view of these experiences it seems reasonable to believe that hard of hearing people would enjoy much greater accessibility and satisfaction if they would own and could use their own receivers  no matter where they go! Firstly, many more public and private establishments would be equipped with transmitters if management did not have to worry about receivers. Secondly, users themselves would ensure that the equipment is working well with fresh batteries installed, and would of course know how to use the receivers with or without their hearing aid.

But is this a feasible proposition?  The answer is yes, it is, provided some conditions are met.

The first condition is that both transmitters and receivers must be made to conform to standards so that all of the user-owned receivers will work with any infrared, FM or loop installation.  While such standards do not exist at present, they would be in the best interests of all parties.

The second condition is that the receivers must be simple to operate. At present some receivers have too many adjustments, dials and buttons, making them difficult and confusing to operate. However, operational simplicity could be achieved with the increasing use of microelectronics and careful design.

The third condition is reliability and robustness. There are no technical or manufacturing reasons why receivers could not be made reliable. Equipment already on the market seldom requires repairs, and the electronics are already very robust. With simplification most controls could be eliminated, allowing the introduction of "unbreakable" designs.

The fourth condition is low cost. Receivers, some of which are quite expensive at present, could be made generally affordable with economies of scale brought about by a large market. This large market would be created if millions of hard of hearing people would begin buying their own equipment!

The fifth condition depends on the four previous ones and is perhaps the most important. This condition is the interest and willingness of hard of hearing individuals to actively accept more responsibility for accessibility. If hard of hearing people could be assured that a standardized system widely supported and serviced by businesses, institutions, and governments is in place, it would then become possible for them to accept this responsibility through the "ownership" of their receivers.

Due to the shortage of time, there was no opportunity to discuss this matter at the Forum. Nevertheless, I believe that this is an important, and possibly decisive, consideration and should be included in a "demand-pull" examination of the assistive listening device field.

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