Hearing Center Network

First, hearing loss is a more complex problem than is understood by the public and by those providing hearing aid services. In addition, our lifestyles are changing, the world is getting noisier, and the hearing-impaired population needs reliable, effective assistance more than ever.

This problem is compounded by the reality that hearing aid practitioners, including both traditional hearing aid dispensers and dispensing audiologists, currently lack the methodology and instrumentation they need to correct or manage their clients’ problems successfully. It’s no wonder people are unhappy with hearing aids and still don’t wear the hearing aids they buy.

The good news is that current digital hearing aid technology, when fine-tuned appropriately for your hearing loss and needs, can dramatically improve your social communications. But, to achieve success today, you must do more than buy a hearing aid to hear your best. You must understand more about the causes and consequences of your hearing loss, and you must verify that you are communicating more effectively before you commit to keeping a hearing aid.

This process takes learning, patience, and an honest appraisal from you and a proficient hearing aid practitioner. We’ve provided more information below to help you understand these issues and ensure a positive experience with your hearing aids.

What is commonly called “hearing loss” could better be described as a loss of speech comprehension. Individuals with such a loss often misunderstand words during conversations. Many report that they hear average and loud sounds quite normally, but they miss some soft sounds. In addition, they have diminished abilities to understand speech, especially in noisy places.

This impairment can be technically and more accurately called sensory-neural auditory processing syndrome (SNAPS) (Magilen 1991, 1995). This is a disability of parts of the ear, brain stem, and brain to extract and integrate information from sound.

A person with SNAPS loses the speed and accuracy necessary to get meaning from speech as another person is talking. The important parts of sound are not properly transmitted from the ear to the brain. The brain may have additional difficulty using what it receives to enable a person to respond appropriately. The complexity of SNAPS increases with age.

An analogy will help explain this concept. Imagine a young father, running down a set of stairs littered with toys as he tries to stop his child from going out the front door. This is not a very difficult task for a young man whose nerves allow for quick, accurate coordination of his movements.

Now imagine an older man attempting the same task. His movements may be slower and less coordinated, especially if he is physically unfit. With speech comprehension, the unfit nerves that cause SNAPS diminish the speed and accuracy of understanding and response.

Nearly everyone with a hearing loss has some level of SNAPS. This is a much more complicated problem than the inability to hear certain sounds. These people have a:

1) loss of audibility

2) loss of speech intelligibility and/or

3) loss that diminishes participation in conversations

is characterized by the inability to hear soft sounds that can be heard by people with normal hearing. It is a consequence of a decrease in sensory tissue function.

, even when they are completely audible. For example, suppose you are in a quiet room and someone asks you, in a loud enough voice, to say the word “KIND.” If you respond “TIME,” that is an example of a speech intelligibility loss.

This can be caused by a loss of sensory or neural tissue. It can also be a consequence of a lack of auditory stimulation (Silman, Gelfand, and Silverman 1984, Hurley 1999). When nerves are deprived of appropriate sound, they become less able to use information from sound effectively. These nerves are unfit to quickly and accurately facilitate speech understanding.

Two people with the same loss of audibility can have vastly different abilities to understand words. Thus, we begin to see that hearing loss is not a simple problem, but instead a complex problem of the ear and the brain to interpret a multitude of speech sounds and stimuli coming in at a fairly rapid pace.

, especially in noisy environments, is the inability to:

1) use anticipation, judgment and recall in a timely manner to comprehend speech,

2) attend to and enhance a speaker’s voice in the presence of competing sounds, and

3) disregard distracting sounds.

Understanding speech in a noisy environment is a complicated task for everyone. A person must use many cognitive functions to hear successfully. Three important cognitive functions are anticipation, judgment and recall. We use each of these functions whenever we need to understanding something.

When you read the newspaper, you have a general idea of what the author is about to say (anticipation), you may pause to question the validity of a statement (judgment), and if you get confused by what you have read, you may glance back and reread an earlier sentence (recall).

The same cognitive processes operate when you hear speech. However, these cognitive functions are harder to use effectively for hearing than for reading.

When you listen to someone speak, it is easier to follow what she is saying if you know what she is going to talk about (anticipation). If she says something you may not agree with, you may have to simultaneously think and listen as you form an opinion (judgment). If you miss something that she says, you can’t replay her speech. Instead, you must ask her to repeat herself (recall).

When we hear, we are under more time pressure than when we read. We can control the pace when we read a newspaper. However, when we hear, the speaker controls the pace and we must rely on the speed and accuracy of our anticipation, judgment and recall functions.

Just as the nerves in our legs become slower and less accurate as we age, the nerves in our brain may slow down and become less accurate. This is why many elderly people have difficulty understanding rapid speech.

Attention and distraction management are additional cognitive functions that must operate effectively and simultaneously with anticipation, judgment, and recall. That is a lot for a person to juggle. Obviously, the more efficiently and the more accurately all those functions operate, the more successful the speech understanding experience.

As we age, our ability to juggle these necessary functions may diminish. Decreases in cognitive function may result from actual tissue damage (e.g., from injury, stroke, or drug use) and/or lack of auditory stimulation.

Regardless of age or medical history, each individual has different capabilities for speed and accuracy with respect to each of these cognitive functions. Therefore, each person has a unique version of SNAPS. In other words, each person has an individual profile of hearing and cognitive strengths and weaknesses.

Our concern is that most practitioners provide their clients with poorly-tuned hearing aids that do not properly address the audibility, speech intelligibility and cognitive challenges facing a hearing-impaired person. This may result in auditory deprivation and maladaption to sound.

Hearing loss can have drastic effects on a person’s quality of life. In the first stages of hearing loss, soft speech and environmental sounds become inaudible, and words lose their crispness and clarity. People often suspect others are mumbling instead of speaking clearly. Misunderstanding words can lead to social embarrassment, and often results in a person’s withdrawal from social activities.

And, once a person decreases their participation in social interaction and conversation, it becomes progressively harder to participate. The effects compound as withdrawal from social activities and communication keeps people from using their cognitive capabilities to their full capacity, allowing them to deteriorate (Willott, Chisholm, and Lister 2001). As the old saying goes, if you don’t use it you lose it.

A landmark study conducted in 1984 illustrates the importance of using hearing aids (Silman, Gelfand, and Silverman 1984). Each participant in the study had a similar degree of hearing loss in both ears, but was fit with only one hearing aid. Over fifteen years, each person experienced a dramatic decrease in speech intelligibility in the ear without the hearing aid, while the speech intelligibility in the ear with the hearing aid remained relatively constant.

Other causes of decreased intelligibility (e.g., noise exposure, medications, dementia, injury, etc.) would have most likely affected both ears equally. It is therefore logical to conclude that a lack of auditory stimulation causes the auditory system to lose its fitness for deciphering speech. Consequently, this can affect a person’s quality of life.

Fortunately, a person’s speech intelligibility and ability to participate in conversation may be improved through the use of appropriately-tuned hearing aids. In fact, many people with well-tuned hearing aids experience increases in speech intelligibility. They report natural sound quality and accommodate to more background noise. This suggests that components of hearing loss can be corrected.

The greatest challenge for the hearing-impaired population is finding a practitioner who will provide them with their best possible hearing experience. Every practitioner will conduct hearing and speech tests and ask questions about audibility, intelligibility and behavior. But, they do not have the knowledge, tests, instrumentation or technical skills necessary to effectively evaluate and manage each individual’s SNAPS profile.

This is because the brain sciences and digital technologies advanced so fast in the past decade, they out-paced the ability of the research and academic communities to apply them to each client’s specific needs. Instead, the practitioners must rely on standardized manufacturer recommendations that are insufficient.

The problem is that, currently, the education and training requirements for hearing aid practitioners are not standardized and do not include a mastery of the subjects essential to properly tuning hearing aids.

In many states, the only educational requirement for becoming a hearing aid dispenser is a high school diploma. Audiologists, who have either a Masters or Doctorate degree, take classes on hearing aid fitting and technology. But their degree programs fail to focus on providing skill-sets necessary to finely tune advanced hearing aids.

Many leaders in the audiology community have suggested and initiated audiology curricula updates. But there is concern that the science background and aptitude of audiology students is insufficient for the rigorous academic program needed to train them to use the new technology (Goldstein 1990, Bloom 2000).

When practitioners, regardless of their educational background, received the first digital hearing aids in 1997, it was as if bus drivers had their vehicles replaced with jet airplanes.

The practitioners were unprepared, untrained, and untested as people with the aptitude to pilot jets. They did not have the knowledge to use the controls properly. They couldn’t fly the jets, so they just taxied them around the runway. People were not happy with the expensive digital hearing aids they bought.

Unfortunately, most hearing aid clients believed the poor performance of the jet was due to the failure of the jet, rather than the “bus driver pilot.” Many practitioners felt that they were doing a good job and were well-educated enough to satisfy their clients.

But in reality, manufacturers had set up a delivery system that put little demand on these unskilled practitioners. It allowed practitioners to fit hearing aids on “autopilot” and used only the simplest functions of the new complicated technology. This usually failed to provide clients with appropriate hearing assistance.

To help practitioners deliver sophisticated digital hearing aids, manufacturers provide suggested prescriptions for varying levels of hearing loss. It is common practice that hearing aid practitioners (traditional hearing aid dispensers, audiologists, mail order companies, HMOs, wholesalers, mass merchandisers, etc.) simply tune hearing aids to these manufacturer recommendations.

In fact, manufacturers often promote the perception that hearing aids are merely commodities that require only minor, if any, adjustments by a professional practitioner. This gives the impression to the hearing-impaired client that personal fine-tuning is unnecessary and should not be expected or demanded.

Unfortunately, manufacturer-recommended prescriptions are based only on a client’s response to a few tones related to audibility and does not account for the loss of speech intelligibility or the ability to participate in conversation. They do not account for each individual’s specific needs and, instead, make generalizations regarding appropriate loudness levels, intelligibility requirements, sound quality settings, ear acoustics, background noise management, and client cognitive capabilities.

In addition, practitioners must consider the physical characteristics of each client’s ear, as well as his or her physical dexterity and social skills. These factors are critically important and vary dramatically for everyone. Manufacturer generalizations should only be a starting point for adjusting a hearing aid to each client’s specific needs. More often than not, they are accepted by the practitioner as the correct fit.

Practitioners sometimes use the manufacturer’s fitting software to show clients a simulation of the sound they should receive with their prescription. This is not evidence of technical expertise and provides little effective value. Actual objective measures of the sound from a manufacturer’s prescription usually do not match the sound promised. This fitting method results in additional, practitioner-imposed auditory deprivation.

Unfortunately, manufacturers discourage the use of objective measuring techniques that can verify the actual levels of sound delivered to each client. And although many practitioners have objective measurement instrumentation, it mostly sits idle as only a few practitioners actually use it.

The way hearing aids are delivered today is not acceptable. Most people with hearing aids continue to suffer with improperly selected and tuned hearing aids that do not provide adequate benefit. Almost always, the value they receive from their hearing aids is not nearly worth the money they’ve spent.

Many of these people are elderly and do not have the information and support they need to challenge this systematic neglect. It continues to harm their relationships and mental well-being. Industry and government must commit to changing the status quo in order to improve the quality of life of hearing-impaired people all over the world.

The complexity of SNAPS and digitally programmable hearing aids requires a new breed of practitioner. They must be experts who are capable of understanding and applying the significant advances in cognitive neuroscience, hearing science, and technology. Using their skills, they must improve each client’s quality of life by pinpointing the nature of each individual’s auditory deficits and recreating a rich, clear auditory experience.

Training an entire industry will take a tremendous amount of time and effort, but it is necessary for success. Current digital technology is capable of addressing many of the deficiencies associated with SNAPS.

A study of our clients in Vallejo Hearing Aid Center, leads us to conclude emphatically that a hearing aid office that aggressively works to 1) proficiently discover the client’s SNAPS profile, 2) selects appropriate hearing aids, 3) fine-tunes the devices with both objective and subjective measures, 4) trains clients with extended trial periods, and 5) provides extensive recall follow-up services, can achieve high hearing aid usage and client satisfaction rates.

Works Cited
-	Magilen, G. (Winter 1991). “The Guided Selection Method of Fitting Hearing Aids.” Audecibel: 16-20.
-	Magilen, G. (May 1995). “Maximizing Sound Quality and Audibility With Hearing Aids” The Hearing Review 2(5): 32-35.
-	Silman, S., Gelfand, S.A., Silverman, C.A. (1984). “Late-Onset Auditory Deprivation: effects of monaural versus binaural hearing aids.” Journal of Acoustical Society of America 76: 1357-1362.
-	Hurley, R. M. (1999). “Onset of Auditory Deprivation.” Journal of American Academy of Audiology 10: 529-534.
-	Willott, J.F., Chisolm, T.H., and Lister, J.J., (2001) “Modulation of Presbycusis: Current Status and Future Directions.” Audiology & Neuro-otology 6: 231-249.
-	Goldstein, D. (September/October 1990) “Au.D. Degree in Doctoral Level Audiology: Demographic and Statistical Considerations.” Audiology Today 2(5).
-	Bloom, S. (2000). “Moving to the Head of the Class: A Progress Report on the AUD.” The Hearing Journal 53(2): 19-30.