Learning Outcomes
After this course, readers will be able to:
- Define hearing versus listening.
- Report three “non-auditory” effects of hearing loss.
- State one cognitive benefit of hearing aid amplification.
Introduction
Approximately 48 million Americans experience hearing loss, according to the Hearing Loss Association of America. Indeed, hearing loss is the third most common physical ailment, following arthritis and heart disease. By age 65, one out of three people will experience hearing loss and by age 75, fifty percent of all people are likely to experience hearing loss. For decades, we’ve known that people with hearing loss struggle, strain and have tremendous difficulty understanding conversational speech. It is confusing for the lay public to consider issues relating to hearing and hearing loss, due to a number of practical issues.
Specifically, despite identical audiograms, no two people experience hearing loss the same way. In addition, the audiogram is not a complete measure of hearing. Indeed, the lowest tone generally tested via audiograms (250 Hz) is middle “C” on an 88 key piano, indicating the entire lower left side of the piano is not tested by an audiogram. The audiogram measures specific frequency thresholds in decibels, and these terms (“frequency” and “decibels”) have little/no meaning to the lay public.
Another consideration as to why the public may have difficulty relating to hearing loss is that o ne cannot easily know what one does not hear, any more than one can know what he or she cannot see, taste or smell. Lastly, screening tests for hearing loss rarely include difficulty understanding speech in noise, and of note, difficulty understanding speech in noise is the most common complaint attributed to hearing loss.
2016 Harris Poll
A recently released Harris Poll (May, 2016) was conducted online in the USA. The survey was commissioned by Oticon, Inc. to better understand and illuminate how Americans with hearing loss struggle to participate in conversations, strain to understand what is being said, and how they have difficulty remembering parts of conversations.
Key findings from survey respondents who identified themselves as having hearing loss include:
- 88% frequently miss words in a conversation
- 85% often use more effort than someone without hearing loss to listen to and comprehend what is being said
- 67% do not understand what is being said in noisy places and especially when there are multiple noise sources
- 67% struggle to understand in noisy places
- 52% always or often strain to understand, follow or participate in conversations
- 48% have trouble distinguishing speech from noise
- 43% have difficulty remembering what was said
- 33% feel isolated or unable to “join in” the conversation when there are multiple noise sources
Additionally, half the respondents with hearing loss said restaurants are the most challenging listening environments. In the professional and scientific literature, we see much the same.
Hearing v. Listening
Unfortunately, understanding speech in noise is not simply a matter of hearing. It’s mostly about listening. Although the first 100 years of audiology were about hearing, the next 100 years will be about listening - as we learn more about BrainHearingTM and the abilities and limits of the individual (Beck 2015). Virtually everyone (99% of all people) can hear via hearing aids, cochlear implants, brain stem implants and more. Unfortunately, the larger and more significant problem is listening. Indeed, the most common complaint from people with hearing aids, hearing loss, attention deficit disorder, attention deficit hyperactivity disorder and more, are listening problems. To be clear, hearing is the perception of sound, listening is the ability to apply meaning to sound. Specifically, the problem of not being able to understand speech in noise is generally not solved by making sound louder. Indeed, up to 12 percent of adults with normal hearing, as evidenced on an audiogram, have difficulty understanding speech in noise (Taylor, Manchaiah & Clutterbuck, 2016) as a result of aging, slower processing speeds, working memory, attention, and other factors.
In 2016, some people with difficulty understanding speech in noise seek and acquire retail-based and/or online hearing tests and amplification devices. Although, there is an apparent and logical thought process which motivates these actions, these same processes may be problematic because although they may ultimately facilitate louder sounds, they also make background noise louder, thus making the problem itself (i.e., understanding speech in noise) louder and arguably more frustrating!
Further, although the professional literature addresses and stresses the importance of the listening and cognitive ability of the individual, this important aspect of hearing and listening assessment is generally absent from retail and online protocols. Admittedly, these more advanced and highly personalized evaluations would be difficult to conduct outside of a professional office, suited for these protocols.
Literature Review
These key findings are consistent with the professional literature.
The National Council on the Aging released a report in May, 1999, which included responses from more than 2000 older people with hearing loss and an additional 2000 family members. Their results stated that for older people with untreated hearing loss, the negative effects of hearing loss included; sadness, depression, worry, anxiety, paranoia, less social activity, emotional turmoil, and insecurity. Resultantly, for those who acquired and used hearing aids (i.e., were treated for their hearing loss), they realized better familial relationships, better feeling about themselves, improved mental health, greater independence, and greater security. They reported “most users of hearing aids reported significant improvements in the quality of their lives since they began to use hearing aids…”
Kochkin (2007) identified obstacles which prevent adults from acquiring hearing aids. He reported there are many variables which influence whether or not one elects to seek hearing aids. With specific regard to the consumers attitude toward hearing aids (page 39), Kochkin reports among the top barriers were the perception that hearing aids do not work well in noise (48%), that hearing aids pick up background noise (45%), that hearing aids perform poorly in crowds (42%) and more.
Lin, Yaffee, Xia and associates (2013) evaluated 1,162 older adults (mean age 77 years) with hearing loss and determined their rates of decline on the 3MS (a global test of orientation, concentration, language, praxis and memory) and Digit Symbol Substitution test (a nonverbal test of psychomotor speed and executive function), were greater than those with normal hearing. The scores were 41% and 32% greater (respectively) than their age matched peers with normal hearing indicating a faster rate of decline. They concluded “Hearing Loss is independently associated with cognitive decline and incident cognitive impairment in community dwelling older adults…”
Fortunato, Forli, Guglielmi, De Corso and colleagues (2016) report increasing evidence indicates age related hearing loss (i.e., presbycusis) appears to be linked to cognitive decline and incidental dementia. They state hearing loss negatively impacts quality of life, social relationships, motor skills, psychological aspects and the function of specific brain areas. They report long-term hearing deprivation impacts cognitive performance via decreased quality of communication, leading to social isolation, depression and may facilitate dementia.
Contrera, Wallhagen, Mamo, Oh and Lin (2016) reported hearing loss is highly prevalent among older adults and is associated with cognitive, physical and mental health declines. They state hearing loss often goes untreated and receives little emphasis in primary care offices. The five major obstacles they identified with regard to obtaining rehabilitative care include; awareness, access, treatment options, cost and device effectiveness. With regard to “Device Effectiveness” the authors (correctly) state “device effectiveness is rooted in the concept of the signal-to-noise ratio…” They report that when a person has hearing loss, his/her ability to distinguish between relevant and irrelevant sounds is diminished. Additionally they note in “Future Implications” that improved device effectiveness is an essential step in the process.
Taylor (2016) reported “The Core Message” from audiologists to physicians, patients and people with hearing and listening difficulties should be similar to the one he created. Specifically “Age-related hearing loss is a public health concern of very high priority. It is a high priority because several recent studies using randomized controls show age-related hearing loss (ARHL) contributes to the acceleration of cognitive and physical decline in adults.” Taylor further addresses the burden to society, as he states “Hearing Loss imposes a heavy social, economic burden on individuals, families, and communities, as a hearing loss isolates people…” He states all people over the age of 50 should have (at a minimum) a baseline audiometric screening and for people with a medical history of depression, cardiovascular disease, diabetes, and dementia, an annual screening is recommended.
Beck, Weinstein and Harvey (2016) reported that one’s cognitive or emotional status, neurologic status, and state of mental health impacts their sensory perception, and the opposite is also true. That is, sensory changes can (and do) impact cognitive, emotional, and/or psychological status. Indeed, they report, for the patient with a significant sensory deficit (i.e., hearing loss) it is difficult to imagine that their sensory deficit would not impact their cognitive status! Further, they too, recommend cognitive screenings be associated with hearing screenings in all patients 70 years of age and older. Beck, Weinstein and Harvey note one cannot pragmatically and easily separate cognition, language, and audition as these processes are intimately interwoven and interdependent. That is, each effects the other in multiple and important ways. They advocate “universal cognitive screening of patients 70 years of age and older with hearing loss and/or listening difficulties—even in the absence of obvious signs or symptoms of cognitive impairment. The discovery and management of cognitive issues, which may masquerade as or occur in-tandem with hearing problems, allows the professional to better address the global needs of the patient in a timely manner.”
Hougaard, Ruf, Egger and Abrams (2016) reported recent EuroTrak and MarkeTrak findings, comprising the world’s largest consumer market surveys addressing hearing loss and hearing aid amplification. They report multiple “non-auditory benefits” of successful hearing aid amplification includes; improved quality of life, better relationships in the home and at work, an improved sense of safety and greater independence, as well as improved mental health.
Desjardins (2016) specifically evaluated the relationship between hearing aid use and cognitive performance on six adults (ages 54 to 64 years of age) for six months. Desjardins reported “all participants showed improvements in performance on the cognitive test measures with hearing aid use…” Of note, after hearing aid use was discontinued (for four of the six participants) “cognitive performance scores returned to baseline levels.” Desjardins speculates that perhaps hearing aid use provides an “immediate effect on encoding of working memory and selective attention ability…” Desjardins reports it is reasonable to assume that hearing aids may “lessen the cognitive processing resources a listener with hearing loss must expend to understand speech by effectively compensating for an individual’s auditory impairment and by improving the listening condition…”
Literature Summary
The 2016 Harris Poll and the above cited references indicate the ramifications of hearing loss include much more than just loudness deprivation. Indeed, untreated hearing loss causes multiple, significant, and cascading health problems for the individual, their family, and the society within which they reside. That is, hearing care is health care.
Unfortunately, the solution to hearing loss is not to simply make things louder. Rather, the solution to hearing loss is to make it easier for the brain to acquire and process natural acoustic information via intelligent and beneficial systems, while maintaining all possible natural acoustic information. Of note, each brain and each person is different, there is no single “go to solution” for hearing and listening problems. The best solution for one individual may not be the maximal solution for another. The needs, requirements, and desires of the person listening matter a great deal, and importantly, the needs, requirement and desires of the person listening are not static, they change constantly as the acoustic environment changes.
Oticon’s Opn™ Solution
Oticon Opn™ is the first hearing aid proven to make it easier on the brain. That is, using pupillometry (a well-recognized measure of stress on the brain) to verify stress levels, Opn users experienced 20% less listening effort while trying to understand speech, compared to Oticon Alta2Pro (Le Goff, Wendt, Lunner, & Ng, 2016). Additional studies (summarized in Le Goff et al., 2016) demonstrated that because Oticon Opn users have more available mental resources, they are able to remember up to 20% more of what is said; individual benefit may vary depending upon instrument prescription. Additionally, and perhaps of maximal importance, clinical tests indicate that Opn increases speech understanding (the parameter most important to users) by up to 30%, as compared to other Oticon hearing solutions - again, individual benefit may vary depending upon instrument prescription (see Le Goff et al., 2016 for review of studies).
The newest BrainHearing™ solution from Oticon is powered by the ultra-fast and precise Velox™ platform and employs an ”open sound” approach to expertly manage multiple speech and noise sources, even in complex listening situations. Designed specifically for hearing aids, the Velox platform has the extreme speed needed to manage multiple sound sources. Specifically, the Velox™ platform processes sound data 50 times faster than our own previous high speed processor (note: individual benefit may vary depending upon instrument prescription). The new OpenSound Navigator™ scans, analyzes and reacts to sounds in the environment more than 100 times per second (every ten milliseconds).
Oticon Opn™ employs 64-bands to facilitate extraordinary and precise frequency resolution and sound analysis to better support the brain’s ability to make sense of sound. This superior processing power enables Opn to continually analyze and balance sounds, while removing noise, even between words, phonemes or syllables (depending on the rate of speech, background noise and other factors). Importantly, and of note, surrounding sounds are available to the person wearing Opn. However – these sounds are not intrusive. That is, Opn users can better focus on the sounds they want to hear (even in noise), similar to how people with normal hearing often have the ability to switch their attention to focus on the sound of primary interest to the listener.
Further, the ongoing and real time estimate of the variable signal-to-noise ratio (SNR) occurs across 16 bands. Each band employs an independent analysis approximately every ten milliseconds (yielding some 500 updates per second) while also analyzing loudness, location and the spectral content of speech and noise.
With regard to maintaining and delivering spatial characteristics, the Spatial Sound LX system allows vast amounts of spatial information (i.e., Interaural Loudness Differences, ILDs) to be captured and delivered to the brain, thereby helping the brain know where to focus attention. The system samples ILDs across four bands (0-675 Hz, 675-1500 Hz, 1500-3700 Hz and 3700-10,000 Hz) 21 times per second per band (more than 3 times faster than our own Inium Sense) providing vastly improved and realistic spatial information and awareness, resulting in improved auditory object formation.
Of note, after analysis, sounds are prioritized and balanced so the listener can focus or switch attention as required. That is, the Opn approach to amplification is that the human brain (not a pre-selected software protocol) is the best decision maker as to which sounds should be attended to, and which sounds should be ignored.
With this open sound experience, Oticon makes traditional directionality - designed to focus on the main sound in front and suppress background sounds - a thing of the past. Users can now focus on a conversation while staying attentive to people and things around them and users can switch focus quickly and easily.
Discussion
Although the terms hearing and listening are often used interchangeably, the two terms represent very different concepts. Hearing can be defined as perceiving sound, listening is the ability to make sense of sound. The professional literature and the recent Harris Poll indicate the most important issues for people with hearing loss include much more than simple loudness compensation.
Indeed, missed words, more effortful listening, misunderstanding words, not understanding (or misunderstanding) words in noise, background noise, straining to hear, distinguishing sounds, remembering conversations, isolation, anxiety, sadness, depression, signal to noise ratios, quality of life, social relationships, reduced cognitive performance secondary to hearing loss and more, are the realities, burdens and well-documented problems realized by people with hearing loss.
The essence of audiology’s first century (the twentieth century) was to objectively explore, understand, diagnose, quantify, document and treat hearing loss. Having accomplished the goals of audiology’s first hundred years, the second century of audiology can focus on using those same essential “hearing” building blocks to better understand and address the more global “listening” needs of those with hearing and listening problems.
References
Beck, D.L. (2015): BrainHearing™ – Maximizing hearing and listening. Hearing Review, 21(3), 20.
Beck, D.L., Weinstein, B.E., & Harvey, M. (2016). Issues in cognitive screening by audiologists. Hearing Review, 23(2), 36.
Contrera, K.J., Wallhagen, M.I., Mamo, S.K., Oh, E.S., & Lin, FR. (2016). Hearing loss healthcare for older adults. J Am Board Fam Med, 29(3), 394-403.
Desjardins., J.L. (2016): Analysis of performance on cognitive test measures before, during and after 6 months of hearing aid use – A single-subject experimental design. American Journal of Audiology, 25, 127-141. doi:10.1044/2016_AJA-15-0067
Fortunato, S., Forli, F., Guglielmi, V., De Corso, E., Paludetti, G., Berrettini, S., & Fetoni, A.R. (2016). A review of new insights on the association between hearing loss and cognitive decline in ageing. Acta Otorhinolaryngol Ital 36(3),155-166.
Hougaard, S., Ruf, S., Egger, C., & Abrams, H. (2016). Hearing aids improve hearing and a lot more. Hearing Review, 23(6), 14.
Kochkin, S. (2007). MarkeTrak VII: Obstacles to adult non-user adoption of hearing aids. The Hearing Journal, 60(4), 24-51.
Le Goff, N., Wendt, D., Lunner, T., & Ng, E. (2016). Opn clinical evidence. Oticon white paper retrieved from: https://4f9f43c1b16d77fd5a81-7c32520033e6d1a7ac50ad01318c27e4.ssl.cf2.rackcdn.com/content/17900/17990/15555-9975wpopnclinicalevidence.pdf
Lin, F.R., Yaffee, K., Xia, J., Xue, Q.L., Harris, T.B., Purchase-Helzner, E.,...Simonsick, E.M. (2013). Hearing loss and cognitive decline in older adults. JAMA Intern Med,173(4), 293-9.
National Council on Aging. (1999). The consequences of untreated hearing loss in older persons. Available at: https://www.ncoa.org/wp-content/uploads/NCOA-Study-1999.pdf
Taylor, B. (2016). Interventional audiology – broadening the scope of practice to meet the changing demands of the new consumer. Seminars in Hearing, 37(2), 120-136.
Taylor, B., Manchaiah, V., & Clutterbuck, S. (2016). Using the Personal Assessment of Communication Abilities (PACA) tool. Hearing Review, 23(3), 20.
Citation
Beck, D.L. (2016, September). Issues impacting people with hearing loss and listening problems. AudiologyOnline, Article 17920. Retrieved from https://www.audiologyonline.com.
