Hearing aid advertising and news stories recently have reached a pinnacle in motivating purchasing behavior by referencing disabilities that are certain to scare hearing-impaired individuals (intentionally or not) if hearing aids are not worn.  And, this fear is a great hearing aid motivator, especially when hearing loss and non-use of hearing aids suggests resulting cognitive disorders, using such phrases/terms as:

  • Hearing loss causes memory problems
  • Hearing loss causes dementia
  • Hearing loss affects brain atrophy
  • Hearing loss causes Alzheimer’s disease
  • Hearing loss results in cognitive decline
  • Hearing loss results in loss of brain hearing
  • Hearing loss reduces neural plasticity
  • Hearing loss reduces sexual activity
    • (This one was made up, but expect to see something on this soon. Why not? Hearing loss seems to have become a source of major deficiencies, and these tend to create fear, or scare people).

The “fear” threat is almost as ominous as suggesting that if you don’t get hearing aids for your hearing loss, you may die a slow death.

But, will you die if you don’t get hearing aids?  Yes. 

Eventually, everyone dies whether they get hearing aids or not.  In a sense, the implications point more toward an agonizing “slow death.”  (In the United States, a slow death can refer to anything that is agonizing, painful, or something we just can’t get away from. We may sometimes refer to that as dying a slow death. When used, it is for dramatic effect, as used here).

The above concerns are in addition to other historically-known social issues, even without compounding this list with concerns related to speech and/or language, and physical experiences related to stress. 

Actual and Implied Psychosocial/Social Issues Related to Hearing Loss

(Speech and/or Language, and Physical Experiences Related to Stress Are Not Even Included in This List)

  • Withdrawal
  • Ignoring others
  • Robs one of his/her effectiveness as a human being
  • Embarrassment
  • Lack of confidence
  • Nervousness
  • Insecurity (anxiety)
  • Loneliness (isolationism)
  • Anger
  • Resentment (bitterness)
  • Fear
  • Worry
  • Depression
  • Failure
  • Frustration (anger)
  • Isolationism
  • Avoidance
  • Inattentiveness
  • Disinterested
  • Inability to maintain interpersonal relationships
  • Confusion
  • Denial
  • Insecurity
  • And certainly, a few others have been missed.

Looking at all these possibile effects, it might appear that there is no human malfunction that can possibly compete with hearing loss other than certain death.  As a result of these “attributes” attached to hearing loss, a person having a hearing loss might feel “… as if the whole world was a tuxedo, and they were a pair of brown shoes.”  (Quote modified from comedian George Gobel1).

Based on all of these issues, it is difficult to comprehend that any individual having hearing loss could possibly be normal.  Fortunetely, we know this not to be the case.

“The Big Three Fears” – Cognition, Dementia, Alzheimer’s

Africa has its ferocious “Big Five;” Rhino, Elephant, Lion, Leopard, and Cape Buffalo.   But, with respect to hearing care “motivations,” the “Big Three” hearing impairment fears of today are frequently magnified as: 1) cognition, 2) dementia, and 3) Alzheimer’s disease – and all three are currently suggested to be improved or slowed with the use of hearing aids, according to extensive advertising, promotion, and some reports.  The message to individuals who have hearing impairment is to take their hearing loss more seriously, pointing primarily to managing current or future deterioration by wearing hearing aids.  Of course, hearing loss should be taken seriously. 

But, let’s step back a little to try to understand some of the very basics involved in this heightened interest, starting with cognition, a term battered around rather freely when discussing this issue, and something not easily understood by consumers, or possibly not even by those making hearing aid recommendations.  Readers interested in more detailed information than provided here are referred to psychological and medical sources and experts in this area.  This presentation is intended to scratch only the surface of this issue.

Cognition

Cognition is “the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.2”    

Cognitive abilities are brain-based skills needed to carry out any task from the simplest to the most complex.  They relate more to the mechanisms of how we learn, remember, solve problems, and pay attention, rather than with actual knowledge.  Cognitive processes use existing knowledge to generate new knowledge.  Cognition is, therefore, a broad term covering complicated mental processess involving perception, learning, memory, and problem solving (Figure 1).  Because these mental processing skills all work together (imagine the cogs in a machine), even one weak skill can hinder the process.  In fact, studies show that the majority of learning struggles are caused by one or more weak cognitive skills3.

The concept of cognition is closely related to such abstract concepts as mind, reasoning, perception, intelligence, learning, and many others that describe numerous capabilities of human mind and expected properties of artificial or synthetic intelligence4.

Figure 1. A simplistic orientation to cognition. Incoming information is subject to cognitive processes, which then files the information in a knowledge bank to solve problems and to facilitate output behavior. Because these mental processing skills all work together (imagine the cogs in a machine), even one weak skill can hinder the process. These are also called mediational processes because they mediate (i.e. go-between the stimulus and response).

How Are These Processes Analyzed?

It would seem that to understand this flow of events, that there should be some way to analyze the process.

The processes can be analyzed from different perspectives within different contexts, notably in the fields of linguistics, anesthesia, neuroscience, psychiatry, psychology, education, philosophy, anthropology, biology, neuropsychology, systemics, logic, and computer science5.  These and other different approaches, such as cognitive science, cognitive psychology, and cognitive hearing science6, are emerging as autonomous academic disciplines.

Within psychology and philosophy, the concept of cognition is closely related to abstract concepts such as mind and intelligence.  Thus, the term’s usage varies across disciplines; in cognitive psychology and cognitive engineering, cognition is typically assumed to be information processing in a participant’s or operator’s mind or brain7.

Anatomical

Cognitive abilities or skills are supported by specific neuronal networks. For instance, memory skills rely mainly on parts of the temporal lobes and parts of the frontal lobes (behind the forehead), but stored also in many other parts of the brain (Figure 2).   To retrieve a memory, these areas of the brain must work in coordination with others.  However, with age, some cognitive abilities tend to decline, especially for so-called executive functions and for cognitive abilities that are not used regularly. However, growing evidence shows that decline can be delayed with appropriate lifestyle options and practices, hearing aids or other8,9,10,11,12,13,14,15,16,17,18,19.

Figure 2. Anatomical parts of the brain and their related functions. (Image modified and expanded upon from Patient Educational Center, Harvard Medical School).

 

How cognition relates to hearing aids will be discussed in next week’s post.

 

References

  1. https://www.brainyquote.com/quotes/authors/g/george_gobel.html
  2. “cognition – definition of cognition in English from the Oxford dictionary”. oxforddictionaries.com. Retrieved 2016-02-04.
  3. Learning Rx. Brain Training 101.  Define cognitive thinking.  http://www.learningrx.com/define-cognitive-thinking-faq.htm.
  4. (2016).  Science Daily. https://www.sciencedaily.com/terms/cognition.htm.
  5. Von Eckardt, Barbara (1996). What is cognitive science? Massachusetts: MIT Press. ISBN 9780262720236.
  6. Rönnberg, J. (2016). Hearing with your ears, listening with your brain.  APS Association for Psychological Science. February.

  7. Blomberg, O. (2011). “Concepts of cognition for cognitive engineering”. International Journal of Aviation Psychology. 
21 (1): 85–104. doi:10.1080/10508414.2011.537561.
  8. Michelon, P. (2016).  What are cognitive abilities and skills, and how to boost them?  Sharp Brains Virtuial Summet.  http://sharpbrains.com/blog/2006/12/18/what-are-cognitive-abilities/
  9. Harvard Women’s Health Watch. (2016). How can you prevent cognitive decline?  Try this combination strategy, Harvard Medical School.  http://www.health.harvard.edu/mind-and-mood/how-can-you-prevent-cognitive-decline-try-this-combination-strategy
  10. Chittaranjan A. and Radhakrishnan R. (2009).  The prevention and treatment of cognitive decline and dementia: an overview of recent research on experimental treatments.  Indian J Psychiatry, 51(1):12-25.
  11. Mild cognitive impairment (MCI). Mayo Clinic, http://www.mayoclinic.org/diseases-conditions/mild-cognitive-impairment/manage/ptc-20206212
  12. Mild cognitive impairment, Alzheimer’s Association, http://www.alz.org/dementia/mild-cognitive-impairment-mci.asp.
  13. Reichman WE, Fiocco AJ, Rose NS. Exercising the brain to avoid cognitive decline. Examining the evidence.  Aging Health 2010;6(5):565-584.  Featured in: http://www.medscape.com/viewarticle/740651
  14. Deal A.J., Sharrett A.R., Albert M.S., Coresh J., Mosley T.H., Knopman D., Wruck L.M., Lin F.R.  (2015)  Hearing impairment and cognitive decline: a pilot study conducted within the atherosclerosis risk in communities neurocognitive study.  Am J Epidemiol, 181 (9):680-690.
  15. Lin FR. Hearing loss and cognition among older adults in the United States. J Gerontol A Biol Sci Med Sci. 2011; 6610:1131–1136.
  16. Lin FR Ferrucci L Metter EJ et al. Hearing loss and cognition in the Baltimore Longitudinal Study of Aging. Neuropsychology. 2011; 256:763–770.
  17. Lin FR Yaffe K Xia Jet al Hearing loss and cognitive decline in older adults. JAMA Intern Med. 2013; 1734:293–299.
  18. Lin FR Thorpe R Gordon-Salant S. et al. Hearing loss prevalence and risk factors among older adults in the United States. J Gerontol A Biol Sci Med Sci. 2011; 665:582–590.
  19. Parham K Lin FR Coelho D. et al. Comprehensive management of presbycusis: central and peripheral. Otolaryngol Head Neck Surg. 2013; 1484:537–539.

Featured Image: Khalil Center.

Barry Freeman, Ph.D.*

A previous post on this subject suggested that a new era is being entered where consumers no longer have to deal with the hassles of replacement disposable batteries.  Instead, the trend will be to hearing aid rechargeable batteries.

This is a second part of that article and is directed at these trends, concentrating on the differences to be expected between the various types of battery chemistries, concentrating on rechargeable batteries for hearing aids.

 

Effective Capacity of Size 312 and Size 13 Rechargeable Batteries

This information becomes relevant when evaluating the rechargeable options coming to market through manufacturers this year.  For example, as shown in Figures 1 and 2, Silver-zinc (AgZn) rechargeable batteries have more capacity than the other chemistries.  While silver-zinc loses its energy advantages in larger sizes like cell phones and automobiles, no other chemistry can offer the capacity of silver-zinc at the sizes of hearing aid batteries.  At this time, Lithium-ion cannot be scaled down in size smaller than slightly larger than a size 13 hearing aid battery. 

Figure 1. Effective capacity of size 312 rechargeable hearing aid batteries currently available. AgZn has significantly more capacity than NiMH. Lithium-ion is not available in this size.

 

Figure 2. Effective capacity of size 13 rechargeable hearing aid batteries currently available. AgZn has more capacity than NiMH and Li-ion at these sizes.

 

It also is well known that Li-ion batteries lose their capacity over time as shown in Figure 3.  While cell phones, for example, may last a full day when they are new, it is typical for them to lose capacity and, therefore, battery life over time.  This is a common characteristic of Li-ion batteries which tend to lose capacity with each charge.  Although there is no history of capacity-loss with Li-ion batteries that power hearing aids, it is anticipated that they could lose as much as 20%-30% capacity every six months.

Figure 3. Capacity loss of Li-ion batteries over charge cycles1.

 

Lithium-ion capacity loss could impact full-day hearing aid wear time depending on the features and streaming behaviors of users.  As noted in the description of Figure 4, it is probable that Li-ion hearing aid batteries will begin to lose capacity and battery life over time.  Silver-zinc always recharges to full capacity.  It does not have the capacity loss challenges of Li-ion.  However, after about a year, the length of the charge time of silver-zinc will increase until it no longer charges to full capacity. 

Figure 4. Size 13 rechargeable hearing aid batteries after 300 charges. Silver-zinc continues to recharge to full capacity. A characteristic of Lithium-ion is to lose 20-30% capacity after 200 charges. This typically continues throughout the life of the Li-ion battery. Nickel Metal Hydride must be replaced after 300 charges.

 

Battery Life Based on Hearing Aid Usage

The impact of battery capacity loss on users will depend on their hearing aid usage and wear behavior such as features and streaming.  Figure 5 presents a hypothetical use case of the performance of these two different battery chemistries with NFMI (Near-Field Magnetic Induction) streaming hearing aids when they are new, and after 200 charges.  Since silver-zinc retains capacity throughout its recommended one-year life, the hearing aid will continue to perform after a year in the same way it did when it was new.  Lithium-ion, however, typically loses capacity over time and, therefore, it might reduce the wear time of the hearing aid depending on the amount of streaming and features that are activated in the hearing aid.

Figure 5. Hypothetical comparison of the performance of size 13 silver-zinc and Li-ion rechargeable hearing aid batteries with NFMI hearing aids when new, and after 200 charges.

 

Proper Consumer Counseling

Hearing care providers must evaluate the wear habits of their customers and then select appropriate products to meet their hearing needs.  Building consumer trust depends on providing accurate information about the products.  Not all rechargeable solutions are the same so there is a need to know the products and how they perform. 

 

Summary

This should be an exciting time for both providers and hearing aid users as a time is entered when hearing aids no longer will need to use disposable batteries.  It’s a time when counseling and instructions will not require the consumer to learn about replacing the battery and they will not be frustrated by this task.  Most definitely, there will be an adoption and learning curve for everyone as the performance of these different battery chemistries is evaluated, especially as hearing instruments evolve and offer more features and users increase their streaming habits.  The moment should be enjoyed, and perhaps in a few years all can remember the old days when hearing aid users had to change their batteries every 3-5 days!

 

References

  1. Buchmann, I. Basics about batteries. I. batteryuniversity.com (2016)

 

For additional readings about hearing aid batteries, check these posted on this site: May 8, 2012February 17, 2015; January 5, 2016February 9, 2016; February 16, 2016; February 23, 2016; March 1, 2016; and March 15, 2016.

 

*Barry A. Freeman, Ph.D. is Vice President, Business Development of ZPower Battery, LLC.  He is a past-president of the American Academy of Audiology and served on the Academy’s Board of Directors for six years.  He received the Distinguished Achievement Award from the American Academy of Audiology in 2006.