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   Rehabilitation Engineering Research Center
   on Hearing Enhancement

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Dr. Ross on Hearing Loss

Beyond Hearing Aids – Hearing Assistive Technologies

by Mark Ross, Ph.D.

If one dates the emergence of Audiology as a profession from sometime in the late 1940's or early l950's, then for more than the first half of our existence the only technical assistance we could offer hearing impaired individuals was hearing aids.That one device represented the full spectrum of assistive devices available to anyone with a hearing loss.

The hearing related problems that remained, and more often than not there were an abundance of these, had to be accepted as an inevitable consequence of having a hearing loss. Expectations of what could be done were much lower than in the present era, and people were counseled to accept the limitations imposed by their hearing losses (and count their blessings in what the hearing aid could provide).

We live in a different era now, both socially and technologically. The Americans with Disability Act (the ADA), mandating the use of technical assistance for people with disabilities when such use is not "unduly burdensome" (Strauss, l994), testifies to the changes in social attitudes in our country. At the present time, people with disabilities do not see themselves as supplicants humbly accepting whatever assistance the wider society sees fit to offer them. The demand is for "full participation" to the degree that technological developments permit (qualified by the resources a society is willing to devote to realizing its good intentions). Expectations, in other words, are increasing and they are increasing at the same time advances in technological developments permit their realization. For people with hearing losses, hearing aids, even the best of them, are no longer enough. Only half in jest, we can date this new era from the time human beings landed on the moon, the formulation going something like this: "If we can land on the moon, why can't we"...(fill in the need).

As a matter of fact, it was about this same time that the first significant assistive device for hearing-impaired people was developed when Robert Weitbrecht, a profoundly deaf engineer, conceived of a coupling device to send typewritten messages over the phone line (cited in Fellendorf, 1982). The advent of this one device dramatically improved the lives of deaf people in a way that exceeded the most optimistic predictions at that time. What can be accomplished now with all types of assistive listening devices (ALD's), or to be more accurate, hearing assistance technologies (HAT - a term which incorporates visual and tactual transforms as well as auditory enhancements) could hardly be conceived of 30 years ago. In some ways, we have reached the moon; we just don't act like it yet.

The central issues now are not that hearing assistance technologies do not exist, but that too many audiologists are not sufficiently informed about the full range of available devices, nor know how to economically dispense them to clients within our current service delivery practices. The literature on assistive devices has proliferated in the past few years (Compton, 1989, 1993; Compton, Lewis, Palmer, & Thelen, l994; Montano, 1994; Palmer, 1992; Ross, l994). Unlike the situation years ago, when the only technical assistance available was hearing aids, audiologists can now select from a wide range of HAT for hearing related difficulties that go beyond what hearing aids can do. If there is a problem now, it is not that there are not enough HAT devices, but that their very quantity may be a little intimidating to the practicing audiologist.

Detailed information on hearing assistance technologies are not only available in the references cited above, but Palmer (l992) and Compton, et. al. (l994) also provide accurate and up-to-date lists and prices of "starter" and "advanced" HAT displays. Additionally, every issue of the various trade and consumer magazines (e.g. Hearing Instruments, The Hearing Dealer, The Hearing Review, Audecibel, Hearing Health, The SHHH Journal) as well as many professional journals (ASHA Magazine, Audiology Today, Volta Voice) report on new product development and provide addresses for the various mail order catalogues. These are the critical resources for professionals who wants to familiarize themselves with current devices and to keep up with new developments. Therefore, rather than simply adding another reference to this literature, this chapter will present a functional overview of various devices, pausing now and then for examples and personal observations both as an audiologist and a hard of hearing adult.

The first section will discuss a communication needs assessment. The second section will describe existing HATs, ranging from listening systems to signaling and alerting devices. The emphasis will be on systems most likely to be dispensed by audiologists; thus the important area of computer assisted notetaking, real-time speech-to-text transcriptions, or automatic speech recognition will be omitted
(Stuckless, l994).

In the final section, the gap between what can be done with available technology and what is being done will be the major theme. Throughout the chapter, the underlying assumption will be that the help that clients can receive with a HAT may be as significant to them as that they can obtain through hearing aids.

Communication Needs Assessment

In my view, just about every adult whose hearing loss is of sufficient magnitude or sufficient import to require hearing aid assistance can benefit from some HAT in some situations. This may be as simple as a foam acoustic coupler to reduce feedback during normal telephone usage, an infra-red (IR) conference microphone for confidential meetings, a personal FM system for the frequent cocktail party habitue, or a universal receiver for detecting either FM, IR, induction loop (IL) or acoustic signals under a variety of listening conditions.

The point is that if a person has a hearing loss which causes communication problems in some situations, the chances of hearing aids completely eliminating these problems is rather remote. It may be that a client, regardless of the possible hearing-related assistance that a HAT can contribute, will prefer the occasional difficulties to using such a device - because of its visibility or perceived inconvenience to others (e.g. "I can't ask someone to wear an FM microphone"). This is a choice which adult clients have every right to make for themselves; on the other hand, it is the audiologist's responsibility to inform clients of the existence and possible assistance that a particular HAT can offer.

Most clients entering an audiologist's office will know little, if anything, about the number and variety of assistance devices available. They came in for hearing aids and, unless introduced to other hearing assistance possibilities by the audiologist, this is what they will leave with. The audiologist is the primary gatekeeper for anything beyond hearing aids. In the flow chart model that Palmer (l992) presents for an assistive devices evaluation, she uses the term "retro-fit" as a failure model. Retro-fitting indicates that on return visits, after the aid has been selected and used for some time, the client reports continued hearing related difficulties in some conditions. The assumption of the retro-fit concept is that some of these difficulties might have been precluded, or a different hearing aid recommended, if the evaluation model had initially incorporated the possible need for assistive devices.

For example, some assistive listening devices can work most effectively and conveniently if the hearing aid incorporates a telecoil. It makes no sense to recommend a hearing aid without a telecoil, only to find out later that the client can really benefit from the use a neckloop in some communication situations. 

The Interview

All audiologists interview their clients before selecting a hearing aid. During the course of the interview, the client is questioned regarding the reasons he or she is seeking hearing assistance in the first place, and the audiologist asks the client to elaborate on the nature of the difficulty and the situations in which it is experienced. This is the time-honored way that audiologists have functioned and, generally, it has served us well.

But not quite well enough, particularly not now when there is an increased possibility of ameliorating some hearing-related difficulty with devices other than hearing aids. People forget. The reader should ask oneself how often, after leaving the doctor's office they remembered that there was some vital point that they wanted to bring up, but forgot? 

To be most effective, an interview format should have some underlying structure that will jog a client's memory. The audiologist will want to explore the following kinds of situations, honing in and asking the client to elaborate on those in which hearing related difficulties are reported: 

  1. One-on-one in face-to-face situations, at home, work, on social occasions, in quiet and in noise.
  2. Group conversations as above.
  3. Telephone and television listening.
  4. Large area listening situations.
  5. In a moving vehicle, or on a noisy street.
  6. Alerting and signaling needs (telephone, doorbell, smoke alarm, wake-up, etc.).
  7. Specific work related communication problems.
  8. Specific problems encountered while traveling.

Once problem situations are identified, then possible means to reduce or eliminate these problems can be explored. As suggested above, however, the kind of HAT that may be most useful for a person will, and should, influence the type of hearing aid that is recommended.

For example, a lawyer who often appears in a courtroom which is either looped, or uses an FM or IR system, will find it most convenient to have a "T" coil incorporated in his or her hearing aid. This will permit coupling a neckloop or silhouette inductor with FM or IR receivers. Furthermore, if it is also necessary for the lawyer to hear spoken comments from an adjacent person, then the hearing aid should include an "M/T" switch.

It is essential that the audiologist be thoroughly familiar with the full range of HAT devices that are available when doing a needs assessment. A client who spends considerable time in group business meetings, and has difficulty in hearing people on the other side of the table, can use a conference microphone.

The question then becomes, what type? Conference microphones can either transmit an FM or an IR signal. If the meetings are confidential (e.g. jury room deliberations, or developing new marketing strategies) then an IR system is required. If some of the group meetings take place in an open atrium, with lots of sun and light, then an FM system would be indicated. If a remote microphone is frequently required (on the street, in a restaurant or vehicle, at receptions, or for small business meetings, etc.), then for maximum flexibility, a personal FM system should be considered (Ross & Yuzon, l994).

The forgoing should make it apparent that a detailed needs assessment must relate the hearing aid selection process with the possible utilization of specific HAT devices.

The Questionnaire Approach

Many clinicians use self-report scales, such as the CPHI ( Demorest & Erdman, l986) to determine the need for some HAT. These scales will chronicle situations in which communication problems are experienced and provide some indication of how a client rates the significance of these problems. Their structure permits the sampling a range of potentially difficult listening situations and the client's reactions to them. During the counseling sessions, based on the information in the self-assessment questionnaires, the auditory activities of daily living are analyzed and potential HAT solutions examined.

Though these scales can be quite useful, particularly in the hands of a sensitive and experienced clinician, they were not specifically designed for HAT selection. Included in the monograph edited by Compton, et al. (l994, Pp. 51-56) is a scale specifically for HAT selection. This scale includes (l) a history of hearing aid usage, (2) a detailed examination of listening situations, (3) various kinds of possible alerting needs, (4) a listing of devices already being used, and (5) special communication systems available in the community. Although the scale is comprehensive, it is organized in a check-list format that should expedite its administration to clients. Later in the same monograph, device selection procedures are described which take into consideration such factors as user preferences, user limitations (dexterity, finances, etc.), environmental influences, and so on. Palmer (l992) has systematized the selection process by developing an interactive computer program. This software sorts through all the possible HAT solutions to identify those that meet the needs of a particular individual. Through a series of questions, the computer program leads the clinician to a specific product, and then provides cost and ordering information. For example, when the program opens it provides three general choices to the clinician (alerting devices, personal communication systems, and other devices). If an alerting device is required, this box is checked and a new window is opened. This window displays the various types of alerting systems (telephone, doorbell, alarm clock, smoke, etc.). When a choice is made here, further windows are opened and the program eventually terminates on specific devices.

Hearing Assistance Technologies

Large-Area Listening Systems

This refers to listening situations in which persons with hearing loss find themselves sitting in the audience at a theater, movie house, lecture hall, auditorium, or house of worship. In other words, any place open to the public in which the signal source is delivered to a group of people in a large enclosure, amphitheater, or open field.

In these kinds of circumstances, audiologists often get called upon to serve as consultants to justify and help select an appropriate HAT, or may be asked to advise a client regarding the most useful listening device. Given the acoustical realities existing under large-area listening conditions, one can assume their necessity for most of the hard of hearing people in attendance (Bankoski & Ross, l984; Ross, 1992).While religious organizations are exempt from the communication access requirements mandated by the Americans with Disability Act (Strauss, l994), they are usually amenable to accepting the need for such a device out of a genuine concern for the welfare of their congregants. There are three types of large area listening systems now in use: FM, Infra-Red (IR), and Induction Loop (IL).

Each will be discussed briefly in terms of its most significant features, and advantages and disadvantages. They all serve to bridge the acoustical space between the sound source and the listening device, thus minimizing the impact upon speech perception of distance, noise, and reverberation (Ross, l992). They can make all the difference between understanding and appreciating a performance, lecture, sermon, etc. or leaving such an event angry and frustrated, determined not to expose oneself to the same kind of no-win situation again.

Induction Loops (and Telecoils)

Unlike a Public Address system, which converts relatively low level input sound signals (or the sound track) to high level output sounds emanating from loudspeakers, an IL system converts the input sound signal to electromagnetic waves which radiate from wire loops placed around the listening area (Lederman & Hendricks, 1994). These waves are detected and converted into an alternating electrical current by an induction coil (termed the "telephone coil") in the hearing aids. This current is increased by the hearing aid amplifier and then reconverted back into sound delivered to the hearing aid receiver (the "loudspeaker"). The wire loop is placed around a room, or some portion of the room, and the person wearing the hearing aid must remain with the loop in order to detect the electromagnetic waves emanating from it. While IL loops can, and do work quite well, their effectiveness may be limited by several factors.

While portable loops can be employed, their installation and removal is time-consuming and, because they are temporary, quality control checks are not as rigorous as they would be with permanent loops. Generally, therefore, IL systems require a permanent installation; once in place, unlike the other two large-space listening systems, they usually stay in place, with a consequent reduction in use flexibility. Unless the loop is geometrically configured appropriately, there tends to be intensity variations in the magnetic field, with the strongest signals received closest to the loop.

The presence of stray electromagnetic signals (from florescent lights, power lines, computer arrays,etc.) will reduce the quality of the received sound. Also, privacy may be a problem since some of magnetic field from within the room may be detected outside the room.

The biggest problem with IL systems, however, relate to the necessity for

  1. the person to wear a hearing aid (only about 20 percent potential users do),
  2. for the hearing aid to contain a "T" coil (only about 20 percent of the hearing aids worn in the US),
  3. for the telephone coil to be properly oriented in relation to the magnetic field (to induce a maximum current) and
  4. for the "T" coil to be sufficiently powerful (Compton, 1994).

In many use situations, the inclusion of an "M/T" switch is a vital consideration. The reader will note that telephone usage has not been mentioned (it will be below). While "T" coils were originally developed to detect the fortuitous magnetic field leaking around older telephones (Holmes, l994), as an assistive listening device its potential utility far transcends this original purpose. They are also required when FM or IR receivers need to be magnetically coupled with a personal hearing aid (via a neck loop or a silhouette inductor). Since passage of the ADA, loops can now also be found in airport waiting rooms, on tour buses, and in front of many teller windows, information booths, etc.

It is only recently that their presence and function in the U.S. is receiving sufficient emphasis in consumer and professional circles. One of the major complaints heard from members of the consumer group Self Help for the Hard of Hearing is the fact that their hearing aid dispenser never told them about all the potential uses of "T" coils or how to operate them effectively. (I recognize that memory is fallible, and that many of these people may indeed have been informed about "T" coils; still, it says something about our follow-up programs that the availability and potential usefulness of this important clinical tool did not remain in their memory.) The beauty of a "T" coil is that it is always there. When a hearing aid user enters a looped facility, all that is necessary is for the person to switch on the "T" position, and he or she is "on-the-air". No logistics problems in checking out a HAT, no concern about a weak or dead battery, and no worry about the electroacoustic suitability of the hearing aid (assuming that both the microphone and telecoil responses have been previously checked and are appropriate).

IR Systems

An IR system transmits audio signals by "carrying" it on an invisible infrared light beam. The infrared beam is amplitude modulated by a fixed carrier frequency, usually 95 KHz, which in turn is frequency modulated by the audio signal. The system can accommodate up to nine simultaneous carrier frequencies riding on the infra-red wave, permitting its use with a stereo transmission or for purposes of simultaneous translations. Generally, 95 KHz appears to be the standard frequency in an IR system, making the receivers compatible in most facilities employ an IR system (Lieske, l994).

The IR transmitter can accept an input from a facility's sound system or directly from a microphone. The signal from the transmitter is led to one or more emitters (radiators) physically situated in advantageous locations for light transmission throughout the listening areas. The IR radiation from the emitter is detected by a photo-sensitive diode located on a special IR receiver worn by a listener. This light signal is then demodulated, the audio component is extracted and amplified, and then delivered to the ears of the listener directly or through personal aids using various coupling modes (i.e. neckloops). Installation of an IR system is fairly simple (though the light radiation characteristics must be examined ) and portable systems can be installed with little difficulty.

The major advantage of an IR wave is that its characteristics are those of a light wave, that is the invisible light radiation remains within the room. In any situation where privacy is essential, an IR system is the choice. Adjacent locations can all be fit with an IR system without fear of interference, spill-over, or eavesdropping. They require a "line of sight" between the emitter and the receiver in order to work effectively; turning one's back to the emitter, placing the IR receiver in a pocket or covering the diode with one's hand, will interfere with a clear reception. They are not effective outdoors or in direct sunlight. They may be able operate efficiently in artificially lighted enclosures, even those using incandescent light, as long as a sufficient number of emitters are employed. As in any large-area listening system, it is important that one tries before one buys.

IR receivers come in a number of varieties. The most common is the under-the-chin (stethophone) variety, usually powered by a rechargeable battery. The output of some of these receivers is sufficient except for those people with the most severe hearing losses. Some include an environmental microphone as an additional input for hearing nearby sound sources. For people with more severe hearing losses, or for those who prefer to listen with their own hearing aids, a body style IR receiver can be used and coupled to personal hearing aids with a neckloop or a silhouette inductor. Many elderly people may also find it easier to manipulate and use a body style IR receiver with headphones than the stethophone type of IR receiver.

The FM System

Large area FM systems are basically an extension of personal FM systems which preceded them by some years. They use the same carrier frequencies (40 narrow-band or 10 wide-band) in the 72 to 75 MHz region (Boothroyd, l992) as do personal FM systems and employ similar, though simpler, receivers. Where they differ is in the power of the transmitter which can broadcast to a larger area than a personal FM system. Multi-frequency transmission make it possible to cover facilities with multiple listening areas (the multiplex movie house, for example). They can be easily and conveniently installed by connecting an output from the amplifier of the existing sound system into the input of the FM transmitter. Such systems can also be used with a direct microphone input for live presentations.

The major limitations of an FM system is the lack of privacy. The radio signal is not confined to the facility, but can be detected with any FM receiver tuned to the transmitting frequency. For example, if a new Broadway musical used an FM rather than an IR listening device, it would be a relatively simple matter for someone outside the theater to record an original cast performance. If eavesdropping does not constitute a potential problem, then FM systems are an appropriate and flexible large-area listening device (Ross, l994).

As mentioned earlier, the FM receivers supplied with large-area FM transmitting systems are similar to, but simpler than, the traditional FM receiver. Some are fixed frequency receivers, while others are tunable; some include environmental microphones while others do not; some have rechargeable and some have disposable batteries; and some permit individual ear adjustments while others do not. The type of facility will help determine what receiver characteristics are necessary (in a nursing home, for example, it would be desirable for a fixed frequency receiver to include an environmental microphone). Some of these same units can also be employed with a large TV set in the recreation room and this multiple use possibility should also enter into the decision making process.

Combined Systems and Microphone Technique

Some of the features of the three above systems can be combined. One can, for example, use an FM wireless microphone in conjunction with an IL or IR system. In these instances, the FM signal from the wireless microphone would be detected by an FM receiver which, in turn, would lead to the amplifier of the IR or IL systems. Thus the speaker in a looped facility can enjoy the flexibility of movement permitted by a wireless microphone, but the recipients could still employ their own hearing aids and "T" coils. If desirable, or necessary, it is possible to employ two or all three of the large area listening systems in the same room. In her 1989 monograph, Compton provides a number of creative examples on how the features of different large area listening systems can be combined for maximum flexibility and effectiveness.

When a large-area listening system is combined with an existing sound system, the major variable affecting speech perception in open spaces has been circumvented - the space itself. The signal from the sound track is being directly transmitted to the recipient, thus negating the potential acoustical interference's existing between the loudspeakers and the listeners. Whenever, however, a microphone input is used with the sound system then a different order of potential problems arise. Microphone technique becomes a major factor to consider (Ross, 1991). The greater the distance between a speaker's lips and the microphone, the weaker and the poorer the quality of the signal that the microphone will transmit on to a listener.

When the speech input is coming from a single person, the best solution is to use either a wired or a wireless lapel microphone. When using a hand-held microphone, too many speakers get so involved in what they are saying that the microphone gets used more as a club or as a pointer rather than a sound-detection device. The trouble with fixed podium microphones is that the talker is not fixed; even if the speaker's feet do not move, their heads frequently do. As far as a hearing-impaired person is concerned, it does not take much movement away from a microphone for a signal to drop below audibility. During panel discussions, each speaker should either have his or her own microphone, or be sure to pass the microphone to the next speaker. Floor microphones, preferably wireless FM microphones, should be employed in any meetings which takes questions from the floor. Because of what modern technology can offer, it is no longer sufficient to ask a moderator to repeat a question.

Live stage (not musical) performances are a special problem - solvable, but one that takes somewhat more thought (and expense). In some theaters, a number of microphones may be located adjacent to the footlights, or suspended above the performers. In some smaller theaters, the sound technician may use a large high quality shotgun microphone to pick up the sound signals. The best solution would be for each performer to utilize a miniature FM wireless microphone, each transmitting on a different frequency. These would be detected by a special FM receiver and retransmitted either on a single FM frequency or via the IR system.

Small-Area Listening Systems Excepting hearing aids (which may be a component of the system), when small area listening systems are referred to they usually pertain to conference type microphones, personal hard-wire listening devices, or personal FM systems. Conference Microphones A conference microphone is one that is placed in the center, or as close to the center as possible, of a group of people. This may be for any application that utilizes inward facing seating, such as around a table or in a circle. Some conference microphones employ sensitive pressure zone configurations which can pick up sounds up to 20 feet away (although, the closer the better). The basic justification for a conference microphone is that it effectively reduces the distance between the talker and the listener; the microphone, in effect, becomes the listener's "ears." Built-in batteries provide maximum use flexibility and several are sufficiently small to be completely portable.

The transmission mode may either be via IR or FM. Naturally it is necessary for the user to have the proper type of receiver, or coupling connectors when one's personal hearing aid is being used. As indicated above, if privacy is an issue, then the IR conference microphone is the correct choice; if privacy is not a concern, then either the IR or an FM conference microphone is appropriate. One of the newer generation of IR conference microphones looks like a small (about 9 inches), four sided pyramid with 15 diodes on each face. It comes with four directional microphones that may be placed at strategic locations around the table. An interesting feature of this system is that the overall gain is set by the strongest signal reaching one of the microphones, thus reducing the interfering effect of multiple talkers (the bane of any listening situation for hearing-impaired people).

Personal Hard-Wire Listening Device

This unit resembles a "walkman" style radio or stereo system. It includes one or microphones which pick up the sound, an amplifier which increases the sound level, a volume control and, possibly, a tone control and either headphones or insert ear plugs to deliver the sound to a person's ears. If this sounds like a description of a basic hearing aid, it is no accident. However, because these units are not advertised as "hearing aids", they are not required to obtain the approval of the Food and Drug Administration before they can be marketed. Nevertheless, because they are relatively inexpensive (beginning about $30 with no necessary relationship between cost and performance) and easy to operate, they can fill a necessary hearing niche in some circumstances (Dempsey, l994).

In nursing homes, they can serve as a primary amplification device for some residents who, for one reason or another, cannot or will not use hearing aids. Nurses and aides can employ them as a temporary device to ease the chore of conversing with moderately or severely hearing-impaired residents. In hospitals, they can be used with patients whose hearing aids have been misplaced or with those who need, but who do not have, hearing aids. It is difficult not to feel or convey a feeling of anger or annoyance when it is necessary to shout at someone in order to be understood. A personal hard-wire listening device can preclude this from happening. They can be used to ease the communication task in noisy vehicles. Recently, I recommended such a system for a hearing-impaired "back-seat" passenger who often takes long rides with his family; with the earphones on his ears, and the microphone placed between the two front seats, he was now "tuned" in to the ongoing conversations much more effectively than he could be with his personal hearing aids.

Personal FM Systems

A personal FM system offers a hearing-impaired person an opportunity to have a "third-ear", one that can be placed close to the source of the sound. At the present state of the art, there is no better way to increase the speech to noise (S/N) ratio than to locate a microphone close to the speech source. And the S/N ratio, of all the factors underlying speech perception, is probably the most important. In my opinion, a personal FM system is the HAT that offers a hearing-impaired person the greatest possibility of improving speech perception in the largest number of listening situations (Ross, 1992). Until recently, in order to use an FM system it was necessary to wear a body type receiver and couple the output to personal hearing aids (or wear a self-contained system, which adults did very rarely).There is now available several BTE/FM systems in which the FM receiver is incorporated into a behind-the-ear hearing aid. The microphone/transmitter can either be the traditional lapel microphone, body-pack transmitter type or a integrated unit about the size of an eyeglass case and half the width.

The potential uses of a personal FM system has been described in several recent publications (Ross and Yuzon, l994; Yuzon, l994). A personal FM system will be most useful on occasions when one wishes to have an artificial third "ear" placed closer to the sound source than one's biological ears. Thus, in a noisy restaurant, street, or vehicle, the microphone can be worn by one's companion; it can be given to the speaker in lectures or classes; hand-held during noisy parties and receptions; placed close to a television loudspeaker or plugged into the audio-output of the TV set or VCR; or used as a conference microphone (best done with the addition of another microphone plugged into the auxiliary input). It can conveniently be carried in a pocket or a purse and taken out when needed.

Television and Telephones

These two listening situations comprise a good percentage of the complaints made by hearing-impaired people. HAT alternatives are well advanced for both. If a client is having difficulty understanding the TV, or communicating on the telephone, the chances are that there are technical solutions available which should help reduce these difficulties. No communication needs assessment would be complete if these two potential problem areas were not examined in detail.


Turning up the TV set rarely helps. As a matter of fact, it is one of the most frequent indicators of a hearing loss, and one of the prime reasons why families nag their hearing-impaired members to "go get a hearing aid". But, after getting a hearing aid, complaints persist. Sure, the sound doesn't have to be turned up so loudly, and it is easier to understand, but too much is still missed. There are two kinds of solutions: one auditory and one visual (or both).

For the auditory solution, there has to be some way of transmitting the TV sound directly to the listener, bridging the intervening distance. There are any number of ways that this can be done (Davis, l994). The audio signal can be picked up by placing a microphone next to the loudspeaker, or by plugging into an audio-out jack from the TV set or the VCR (some cable connections also provide an audio output jack). This audio signal can be sent to either a small FM or IR transmitter which is usually placed on the top of the TV set. The signal from this transmission is picked up by the listener, either using dedicated IR or FM receivers or by coupling these receivers to personal hearing aids. What can be useful for elderly nursing home residents, who have difficulty managing headphones or a personal FM receiver, is an FM receiver and amplifier integrated into a self-powered loudspeaker. One of more of these can be placed in a convenient location close to the listener. Special TV radios, which can be tuned to the audio signal of the network broadcasts, can often serve this same purpose. These are only some of the possible ways that TV audio reception can be improved.

Since July 1993, all TV sets greater than 13 inches made or sold in the United States must include capabilities to access closed captioning. More and more TV programs are being captioned and this development has been of immense importance to people in the Deaf community, who are well aware of its desirability and availability. Many hard of hearing people, however, may not know of its availability and desirability for them. One does not have to be severely hearing-impaired to enjoy the increased enjoyment of TV programming that closed captioning can afford (as attested to, among other people, by one of the co-editors of this volume!). A little encouragement may be all that they need.


There are devices and techniques to improve telephone communication for just about anybody with any degree of hearing loss. For the person who, under optimal conditions, is functionally hard of hearing, these optimal listening conditions can be provided for in telephone communication. At it's simplest, all that is required is an amplified handset, the most common models of which can provide 20 dB of gain. This may be all that is necessary for unaided telephone communication for many people with milder hearing losses (Holmes, l994). Many other people can acoustically couple a telephone to their current hearing aid (though usually not BTE aids), and even more can do so with the assistance of a foam pad on the earpiece to reduce feedback. Thus it may appear that telecoils are unnecessary for many people with mild to moderate hearing losses. This may be true for telephone communication, but it does not negate the importance of a telecoil as an assistive listening device, as discussed earlier.

For anybody with a moderate hearing loss or greater, and who is functionally hard of hearing, a good telecoil used with a compatible telephone (which most phones are now, thanks to The Hearing Aid Compatibility Act of l988, and the Americans with Disability Act of 1990) is still the most effective acoustic method of telephone communication. However, extra assistance is available if needed, including in-line and portable amplifiers, and induction systems which direct the telephone signal to both ears. If the client works in an environment with a great deal of electromagnetic interference, thus negating the effective use of inductive coupling to the telephone, then direct audio input (DAI) connectors from the telephone to the hearing aid are available. In other words, once telephone communication problems have been carefully defined, there are solutions if one looks for them.

For people who are functionally deaf, or for whom acoustic telephone communication is too difficult, TTY's provide an effective substitute (Castle, l994). If both parties have a TTY machine (also termed Text Telephone), then messages can easily be typed back and forth through the telephone lines. Deaf people have been using this technology for 20 years. We can, however, inform severely hard of hearing and late deafened people about the communication possibilities of TTY's, show them how to use a TTY, and notify them about the various kinds of telecommunication relay services. It is possible, for example, for a hearing person to speak to a relay operator (the communication assistant, or CA), who will in turn type to the Deaf person. Conversely, the Deaf person can type to the CA, who will relay the message orally to the hearing person. Other variations are possible (for an extensive discussion, see Castle, 1994).

Alerting and Signaling Devices

Just about every sound producing event used by normal hearing people for signaling or warning purposes can be coded into a visual or vibratory stimuli for the benefit of hearing-impaired people. In the commucation needs assessment, the audiologist should have determined the problem situations.

The solutions are many and varied, ranging from the simple to the complex, and are no further than the closest assistive devices catalogue. No hearing-impaired person need be denied awareness of important environment sounds (Jensema & Lennox, l994).

If a person cannot hear the telephone ring, there are devices that use the telephone ring signal as a power source to flash a strobe or incandescent light. Remote units can be set up so that the light will flash in adjoining rooms as well. A portable sound-activated unit can be used while traveling. Doorbells can be wired to flash a light, or a door knocker can be placed which flashes a light when someone knocks. There are smoke alarms which flash powerful strobe lights when smoke is detected; remote lights can be set up in various rooms. Alarm clocks can employ light or vibration to wake up a sleeper. Deaf parents can be alerted to the sounds of their baby crying by a sound activated light, or by a motion detector (for the older adventurous baby exploring off-limit areas). A comprehensive alerting system can be purchased, with individual sensors for the different doors, telephones, fire alarms, children's room, etc., each with its own response code. Vibratory paging systems can alert a hearing-impaired person to important information, and even include brief messages.

Hotels are required by the ADA to provide signaling and warning devices upon request (and a television set which includes captioning capabilities). Having once been caught in a hotel fire with my hearing aids off, I always make sure that the hotel includes a visual smoke alarm in my room whenever I travel. Also available in hotels are amplified telephones, and alerting devices for the telephone and wake-up calls. All of which permit a relaxed night's sleep.

Service Delivery Models

Several years ago a survey of facilities and individuals was conducted which queried various dimensions of hearing aid dispensing practices (Malinoff, D. Kisiel, S. Kisiel, & Dygert, l990). One of the questions asked the respondents to rank the factors which they felt were most important in providing better service to their clients. Aural rehabilitation and assistive devices ranked the lowest (behind quality of instruments, service and maintenance, follow-up, and expedited delivery). No service delivery model conducted by hearing aid dispensers can be effective if the service itself is not valued. The clue to their attitude can perhaps be seen in their responses to an earlier question, which indicated that only one to three percent of their income was derived from assistive devices. Somehow, it seems, the respondents were able to convince themselves that any service that was not significantly income producing could not be important. But, of course, the problem is circular: if the value for the client of assistive devices is not recognized, then there will be little incentive in trying to develop an economically viable service delivery model.

Compton, et al (l994) suggest that professional time and not the product cost be the crucial consideration in dispensing assistive devices. The evaluating audiologist does the communication needs assessment, selects the appropriate HAT, instructs the client in its use, does some kind of follow-up, and charges on a fee for service basis. The product itself is dispensed at or slightly above cost. The most logical time to evaluate and select assistive devices is in conjunction with a hearing aid evaluation and selection. It seems to me that one major obstacle for the adoption of this model is that audiologists have not convinced themselves of the value and contributions of HAT to their clients. And if they're not convinced, they can hardly convince their clients and institutions to adopt a fee for service policy as it relates to the evaluation and selection of HAT devices. The picture is not uniformly gloomy; at least some hearing aid dispensers are finding that assistive devices can be effectively marketed within the constraints of our current service delivery system (Thelin, l994).

The gap is being filled by many non-profit agencies, such as hospitals, Universities, and fraternal organizations who have developed "Assistive Devices Centers". A number of SHHH groups have sponsored and staffed such centers. Typically, the client is led into a separate room. On the door, there may be three different ways to signal a visitor; going into the room, the client may be shown a half dozen ways to alert a listener to the telephone ring; a dozen different telephone amplifiers and handsets may be scattered on a shelf; on the ceiling and walls various types of smoke alarms will be displayed; on different shelves a number of types of wake-up alarms, paging systems, and personal listening devices. In the room, there is a TV set hooked up to a VCR. On the set there may be three different transmitters, with four different kinds of receivers by a viewing chair. And so on. As proud as centers may be for the variety of HAT possibilities they can offer clients, the response is mainly confusion and uncertainty.

Clients need a guide through the morass; a guide, moreover, that focuses on specific devices depending upon a client's expressed needs. When the assistive devices center is located in a professional center with the necessary commitment to HAT devices (such as in N.Y., The League for the Hard of Hearing, Brooklyn College, Manhattan Eye and Ear Hospital) the main guide is usually a professional. When the center is sponsored by a fraternal organization or a SHHH chapter, the guides are frequently knowledgeable volunteers (usually individuals with hearing loss) who attempt to work closely with a client's dispensing audiologist. There are no standards. Some places give demonstrations to the public on a periodic basis; some may dispense the units, while others refer people to the person's hearing aid dispenser; others may refer clients to a catalogue item or an electronics store; and some centers may provide temporary loaners, with or without supervision. In spite of this chaotic system (or lack of it) many people are helped.

We can do better. The first step is for professionals to recognize the significant value of assistive devices for many of their clients.

Once this is explicitly acknowledged, then the search for an effective service delivery model can begin.

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