Alan R. Ehrlich, Chair, Listening Disorders Division, Global Listening Centre
Past President, Global Listening Centre (www.globallisteningcentre.org)
Past President, International Listening Association (www.listen.org)
Introduction
The act of listening–using our ears and our mind together to interpret and experience sound and language in the fullest possible way–is one of life’s great pleasures (Heymann & O’Donnell, 2010 p. xix).
Millions of people around the world have difficulty listening—using their ears and mind together to understanding spoken language. From the consonant filtering of hearing loss, the confusion sowed by Auditory Processing Disorders (APD), the impenetrable walls of clinical depression and extreme narcissism, there are many physiological, cognitive and psychological disorders that reduce an individual’s ability to effectively understand what is being said. When you add [to this mix], the exogenous barriers that exist [in our society], communication becomes difficult for many. The fact is that millions of us are listening disabled.
Each of us assumes that when we speak, people understand what we are saying. We also assume that when we listen, we truly understand all of what has been said to us. But the reality of these assumptions do not apply to millions of us. The study of listening disorders can begin to answer the question of why so many people cannot listen effectively.
Three Old Gentlemen
There is an old, humorous story about three elderly gentlemen. They have been neighbors and friends for well over 40 years. Over the past decade, they would get together twice a week for a few hours, walking through the local park, sharing memories, events of the week, and, every so often, a beer.
On a particularly windy day, they chose to break up their walk and sit on one of the small wooden benches overlooking the lake. After a few minutes, the wind began to pick up. “Windy day,” remarked one of the gentlemen. The guy sitting next to him pondered the remark for a few seconds and responded, “Nope, it’s Thursday,” quickly followed by the third gentleman excitedly exclaiming “So am I, let’s go have a beer!”
It’s not that these gentlemen couldn’t hear, because if they couldn’t they wouldn’t have responded at all. What they couldn’t do was understand what was being said. But as humorous as this might seem, situations like this—people responding inappropriately to what they think they hear—could cause tremendous embarrassment, loss of friendships, tears in the fabric of the family, self-isolation, depressions, and more, because having a listening disorder is anything but funny.
Grandparents, Crazy Uncles, and Our Teenage Kids
Many of us have had the experience of dealing with a grandparent, parent, ‘crazy’ uncle, or older neighbor who has a significant hearing loss. The truth is that statistically, about one-third of people between the ages of 65 and 74 have a hearing loss with this percentage increasing to above 50% for those over 75 (Sprinzl & Riechelmann, 2010).
According to the World Health Organization (WHO), over 5% of the world’s population, around 466 million people worldwide have disabling hearing loss, and 34 millions of these are children. Experts at WHO estimate that by 2050 this number will grow to be over 900 million—or one in every ten people (WHO, n.d.).
But while hearing loss is often associated with aging it is a disability that truly spans the ages. According to a 2011 study at Johns Hopkins published in the November 11th Archives of Internal Medicine (Lin et al., 2011), nearly a fifth of all Americans 12 years or older have hearing loss severe enough to make communication difficult. Regardless of the individual’s age, communicating with those with a disabling hearing loss can be both difficult and frustrating.
The most common cause of hearing loss in older individuals is presbycusis—the gradual loss of hearing that occurs in many individuals as they grow older. Generally, presbycusis is caused by aging-related changes to the inner ear but can also result from changes in the middle ear or the auditory nerve pathway to the brain. Because the hearing loss caused by presbycusis is so gradual, many people don’t even realize that their hearing is being diminished until it is too late.
Presbycusis is one of the types of hearing loss categorized as sensorineural hearing loss which is caused by damage to the structures within the inner ear—generally the stereocillia, the small hair-like structures that line the spirals of the cochlea. Sensorineural hearing loss generally affects one’s ability to hear and discriminate the higher-pitched sounds such as /s/ and /th/ and causes speech sounds to seem mumbled or slurred.
While presbycusis is age-related, noise-induced hearing loss (NIHL) affects people of all ages with generally a hearing loss at the higher frequencies. Like presbycusis, NIHL falls is categorized as a sensorineural hearing loss which, as of today, is a permanent disability with no medical or surgical treatment options to reverse its effects.
NIHL is caused by the sounds in our environment, from the traffic passing by, our televisions, household appliances, our music players, and more. Most of these sounds are at a safe level and won’t do any harm, but loud sounds, both brief impulses (gunshots or explosions), or heard over longer periods of time (listening to loud music, motorcycle riding, etc.), can cause irreparable damage to the sensitive structures within the inner ear.
We measure sound volume in units known as decibels. The higher the number of decibels, the louder the sound. A normal conversation measures around 65 dB, while a motorcycle or dirt bike can measure 90 – 110 dB. Long or repeated exposure to sounds above 85 dB can cause hearing loss. As the number of decibels increases, the exposure time decreases exponentially. For instance, you can listen to music at 85 dB without a problem for up to 8 hours. If the sound level increases just 3 dB to 88 dB, you can begin to sustain damage after only 4 hours. Another 3 dB increase, to 91 dB, reduces the safe-time to under 2 hours. Should the sound level reach 100 dB, riding a tractor without hearing protection for instance, the safe-time is reduced to just 15 minutes. If you raise the volume of most MP3 players to its maximum, around 112 dB, the safe listening time is reduced to less than 1 minute (Ehrlich, 2017)
While a single loud blast like a gunshot, explosion, or even the activation of automobile airbags can cause instantaneous hearing loss, most instances of NIHL, like presbycusis, causes a gradual decay in hearing acuity at the higher frequencies. Early rock musicians (Neil Young, Ozzy Osbourne, Phil Collins, Eric Clapton to name a few) (Academy Hearing Centres, n.d.) who’s shows rocked with very high volume music, now suffer from moderate to severe hearing loss and cannot perform any longer. Classical musicians, especially violinists and those seated in the rows closest to the brass section of the orchestra, are often diagnosed with career-halting hearing loss (Chasin, 1996).
Looking at our teenage kids, or even ourselves using earbuds at the gym, while jogging, or just relaxing at home. we could be putting ourselves in line for a future that includes hearing loss because earbuds can be as dangerous to the ears as working with a jackhammer or riding a motorcycle without hearing protection.
A modern MP3 player or smartphone can produce an audio output of over 105 dB, more than enough power to do inner ear damage with extended listening times. Earbuds, being close to the tympanic membrane, can add another 6 or so dB which cuts the safe-time by around 75%—or less than the time for one music track.
The higher the degree of NIHL, the greater the reduction in hearing acuity, especially at the higher frequencies, which makes communication very difficult.
In the words of one Kansas farmer, after years of riding tractors and other heavy equipment, “You don’t notice a thing until you don’t notice a thing.” (Shelly and Dennis 2002)
Consonant Confusion
The reason that the loss or reduction of the higher speech frequencies creates communication difficulty is that many of the consonant sounds—the sounds that define the words we hear—lie in the high-frequency range and are considerably softer sounding than the lower-frequency, more powerful vowel sounds.
Missing the consonants can create understanding havoc. This can be demonstrated in written form as well. If we take a simple sentence such as, “Listening disorders creates problems.” and remove all of the vowels, we have “Lstnng dsrdrs crts prblms.” If you have any idea of the context that it is being said in, you can generally figure out the meaning of the sentence. However, if we remove all of the consonant, we have “iei ioe eae oe,” a cryptogram that is impossible to resolve.
People with a high-frequency hearing loss struggle to hear many of the consonant sounds (such as /s/, /th/, /f/, or /sh/) which lie in the higher speech frequency range. As a result, speech may sound very muffled, with words missed and misunderstood, especially when in noisy situations. Having the speaker talk louder only compounds the problem since the vowels (the power sounds of speech) can be vocalized louder, but the consonants (the sounds that provide meaning) cannot be spoken loudly (just try to make a loud /f/, /th/ or /s/ sound) and are easily overpowered by the loud vowel sounds. Adding additional complication, especially for school-aged listeners, the voices of their mother, of other children, and of female teachers, tend to be higher in frequency and thus more difficult to comprehend (Ehrlich, 2017).
The auditory distortion that occurs with this frequency filtering distorts the sound stream, making words sound different and unfamiliar, causing the recognition process to slow down. Listening to people that talk fast, have an unfamiliar accent, or even enunciate differently, requires intense concentration and considerable cognitive effort. Even over short periods of time, these needs exceed the cognitive ability of the listener and, as a result, the messages are not understood in the context the speaker desired.
Auditory Closure
Our brain does not do well when speech is degraded by missing sounds, blanks, unrecognizable or misunderstood words. In order for us to continue listening, we utilize a subconscious cognitive process that attempts to accurately fill in the missing or distorted portions of the auditory signal. This action, called auditory closure, is accomplished in real-time so that the listener never realizes that a word or phrase had been missed or degraded, they just go on listening as if every word was clearly received.
Auditory closure involves taking small pieces of auditory information—parts of words—and matching it to information resident in the listener’s contextual memory—finding a close match, one that makes sense within the conversational context, and substituting for the missing or distorted speech in order to help construct the whole message. You can almost compare auditory closure to your spell check on your smart phone. Sometimes it picks the correct word, and sometimes it picks something so out of context that you have to laugh. Hopefully, auditory closure is a bit more accurate than spell check.
Using the example of the three elderly gentlemen discussed above, the word windy produced just enough auditory information to trigger the substitution of Wednesday, but not enough to fully form and accurately recognize the word. The same issue occurred with the word Thursday where the last gentleman was led to believe he had heard the word thirsty (which he obviously he was).
Auditory closure is generally more accurate with adults because of their broader experience set and their use-of-language experience. Whether the adult is conversing about work or social subjects, they generally have a good foundation in the subject being discusses. Children, on the other hand, don’t have the broad experiences of older folks and are often in situations where the subject is new and changing often such as their school day schedule.
While it is easy to laugh at the off-the-wall responses of the three old gentlemen above, think about how devastating it would be in your work environment. You’re asked a question and you provide a response that has nothing to do with the question. It could lead to incorrect information being written into a contract or sales order or totally confuse the individual who is interviewing you for your promotion. If done on a regular basis, it could cost your job.
For children it could be the cause of ridicule and mockery. It could lead to being called out by the teacher thinking that you’re not paying attention to what is being said. The result, in many cases, is that the child withdraws in order to avoid further embarrassment.
Note to Educators: Please impress upon your students the need to review the class material before the class. By doing this they will have a familiarity with the vocabulary and phraseology that will be used in the lesson of the day, increasing their ability to successfully use auditory closure when the need arises.
Minimal Hearing Loss
While it may be easy to assume that our three elderly gentlemen have a significant, untreated hearing loss, the fact is that it doesn’t take much of a hearing loss to create a communication problem. Even a minimal high-frequency hearing loss, especially in children, can complicate communication. In children, a minimal hearing loss can greatly affect their potential for academic achievement.
Minimal hearing loss (MHL) is the term used to describe a level of bilateral sensorineural hearing loss between 16 and 25 dB (Pease, 2011). This level of hearing loss will generally not be picked up by the standard pure-tone hearing test. The American Medical Association assumes that there is no disability below 25 dB and the disability grows linearly above what the AMA considers this ‘low fence’(Dobie, 2011). But for school age children, even a minimal hearing loss can be academically debilitating. And unfortunately, there are a significant number of children that fall into this category (see Bess, 1999).
It is estimated that 5.4%, roughly 2.5 million school aged children—or more than one in twenty—exhibit Minimum Sensorineural Hearing Loss (MSHL). This does not include the children with higher levels, moderate or severe, hearing loss (Bess, 1999).
Bess (1999) went on to show that 37% of children with MSHL failed at least one grade compared to a district norm of about 3%. This not only affected the children’s academics in a very negative way, but also placed a huge financial burden on the school district. With approximately 46 million school-age children in the United States in 1999, about 2,484,000 would exhibit MSHL. Of these, 37% (919,080) could be projected to fail at least one grade. If one assumes that the average cost to educate a child for one year is $6,000, the total expenditure for grade repetition exceeds $5.5 billion in the US alone!
Disconnects
While we assume that the people we are talking to understand what we are saying, the more we learn about listening disorders (e.g. hearing loss) the more we need to be aware that not everyone hears, or listens, with the same acuity.
The reduction of auditory fidelity—hearing loss—is a disconnect between the sound source and the brain. If the listener is blocked from receiving the full spectrum of speech, including the slight, but important tonal intonations that indicate emphasis, surprise, irony, or to pose a question, the meaning of what is being said can be altered and misconstrued.
Another disconnect can occur between what is heard and the brain’s ability to make sense and use the sound information that the ears passed on. This neuro-cognitive disorder is generally labeled as Auditory Processing Disorder.
Auditory Processing Disorders
Millions of Americans have difficulty understanding spoken language. They are not deaf, autistic, or slow. They have APD (Bellis, 2002, intro).
The prevalence of APD in the general population has not been firmly established. While studies have shown a substantial variation, in every case the numbers are significant. Chermak and Musiek (2013) estimated that APD occurs in 2 to 3% of children, with a 2-to-1 ratio between boys and girls. Cooper and Gates (1991) estimated the prevalence of adult APD could be as high as 20% with its prevalence higher in the elderly and increasing with age. Others believe that in the US, 5% of school-aged children—roughly 2.5 million children—have APD yet a small study in the US Mid-Atlantic Region (Nagao et al., 2016) indicated a prevalence of just 1.94 per 1,000 children.
Edward Barlett of the Hearing Health Foundation estimates that 15% of military veterans live with APD due to post-blast trauma (Hearing Health Foundation, n.d.) and feels that it may account for the behavioral issues (memory, learning, communication and regulation of emotions) that plague many of our returning troops.
Regardless of the differences in the studies, each show that APD is a disability that affects the listening acuity of millions of people. It is important to realize that most of these listeners have normal hearing but their brains have difficulty in receiving, organizing, and interpreting the information. There is a disconnect between what is heard and what is understood.
Most cases of APD are diagnosed in children, specifically about the time they begin to attend school. It is not unusual for a family’s routine to make it difficult to spot problems with their kids as they grow. Older children often speak in place of their younger siblings which can hide delayed language development while parents generally repeat the same phrases and intonations when they speak to their children. They get so used to the child’s responses that they don’t recognize the potential symptoms that might be hampering the child’s auditory development.
Children with APD may have difficulty understanding speech, especially in noisy environments; following directions; continually requesting the speaker to repeat what was said; have difficulty maintaining attention; difficulty learning to read and spell; and do poorly in classes that require intensive listening skills although they do well in classes that do not rely on their listening ability to achieve high grades.
A key point that Heymann (2010) makes is that:
Children with APD encounter nearly insurmountable obstacles to understanding, learning, and enjoying themselves each and every day. In ability or difficulty transforming passive hearing into active listening makes academics challenging to master and many social situations emotionally painful and difficult to endure. Left unidentified (through screening), undiagnosed (through evaluation) and untreated (through coordinated therapy and intervention), an auditory processing disorder can hold an otherwise bright and willing child back for life (p. xxi)
One reason why it is difficult to ascertain the prevalence of APD is that the presentation of APD is very similar and often confused and misdiagnosed with other disorders such as Attention Deficit Disorder (ADD), Attention Deficit Hyperactivity Disorder (ADHD), Pervasive Developmental Delay (PDD), Autism Spectrum Disorder, Sensory Processing Disorder, Receptive Language Disorder, or Mixed Expressive-Receptive Language Disorder. Each of these conditions could affect how a child processes spoken information and can cause speech-language delays, but it is important to note that not all children with speech-language delays have an auditory processing disorder, and conversely, not all children with APD have a delay in their speech and language development (Auditory Processing Center, n.d.).
Most often, APD is mistaken for and misdiagnosed as ADHD as both of these disorders share multiple diagnostic characteristics such as the inability to sit still, ease of being distracted, inattentiveness, and lack of impulse control.
Since ADHD is better known and easier to ‘diagnose’ than APD, it has become the catchall diagnosis for these children. Often, after a number of classroom interruptions or continually poor grades, the child is sent for an evaluation, generally by a pediatrician but rarely a pediatric hearing specialist. Since the presentation of both disorders are almost identical, the child is said to have ADHD and sent home with medication—without ever being seen by a pediatric audiologist.
I estimate that perhaps one-quarter (25%) of the population currently being treated with Ritalin and Adderall for ADHD/ADD really have APD or minimal to mild hearing loss and get no real benefit from their medication. What is worse, they are not getting the proper treatment and services for the disorder that they do have.
Auditory processing problems can appear at any point in life, but when APD occurs in infants and children, it can have a dramatic, often devastating, impact on learning, academic success, and even basic interaction with the world (Bellis, 2002. p.68).
Bellis (2002) also points out that the act of listening changes as we move from childhood to adulthood. While children are expected to be active listeners who attend to understand, and respond to the speaker appropriately, as adults, sometimes the less we say or do, the better listeners we seem to be. Good listening is more passive as adults and often just being there and nodding at the right moments is enough to indicate that you heard, processed and understood the verbal message… even if you didn’t.
But not everyone with APD present obvious difficulties during their childhood years. In some cases, APD does not manifest itself until later in life, when the cognitive conditions are precisely right.
Classes at the University level are significantly different than those in the lower grades. Classes may be held in large lecture halls; professors generally don’t hand-hold their students the way teachers might might in the lower grades; and laboratory classes are generally less structured and allow for students the ability to self-learn.
This could lead to a significant scatter in academic achievement with poor grades in courses that rely on reading, listening, or understanding verbally presented concepts, despite putting forth good effort, while the student excels at classes where the student can learn at his or her own pace.
Students with APD often have to put so much energy into trying to understand what their teacher is saying that they have limited cognitive resources left over for actually engaging with the concepts being discussed. Effective listening requires a number of processes—all working harmoniously together: auditory capture; analyzing the sound stream; organizing the sounds into respective patterns; interpreting the patterns and inferring and understanding their meaning. Being ‘stuck’ at any one of these processes causes a cognitive backlog that cannot be easily overcome.
In Conclusion
Millions of us have a listening disorder that affects our ability to easily and flawlessly listen to spoken language. Listening disorders can be classified into one of three areas: physiological, neuro-cognitive and psychological, with a fourth group that defines the exogenous barriers that limit our ability to clearly and effectively understand what is being said. In this article we touched upon just two—physiological (hearing loss) and neuro-cognitive (auditory processing disorders).
The trouble is that we’ve been listening so long, since before we took our first breath, that we take this incredible ability for granted. We just assume and expect those we converse with to fully understand what we are saying and we get frustrated with those who don’t. We also assume that when we listen, we fully understand what has been said to us, ignoring the potential for a degradation of our own listening acuity. With the tens of millions of people that have a listening disorder, such as a hearing loss or APD, we have to question whether these assumptions really hold up? Even for ourselves!
Hearing loss in the elderly can be a tag line for humor, but when you take into consideration the physical, neurological, psychological and social ramifications of hearing loss, it no longer can be viewed in a humorous vein. Hearing loss can be the cause of severe social and health problems as it significantly impairs the exchange of information (think doctor-patient communication), exacerbates loneliness, isolation, dependence and a creates a high level of frustration within one’s self.
A JohnsHopkins Medicine/National Institute on Aging study shows that seniors with hearing loss are significantly more likely to develop dementia over time than those who retain their hearing.
Researchers have looked at what affects hearing loss, but few have looked at how hearing loss affects cognitive brain function,” says study leader Frank Lin, M.D., Ph.D., assistant professor in the Division of Otology at Johns Hopkins University School of Medicine. “There hasn’t been much crosstalk between otologists and geriatricians, so it’s been unclear whether hearing loss and dementia are related (JohnsHopkins Medicine, 2011).
The link between hearing loss and dementia remains a mystery but the correlation between the two is well proven.
A lot of people ignore hearing loss because it’s such a slow and insidious process as we age,” Lin says. “Even if people feel as if they are not affected, we’re showing that it may well be a more serious problem (JohnsHopkins Medicine, 2011) .
Hearing loss in children, however minor, can severely limit the child’s academic achievement, social interactions, life-goals, and long-term earning capacity.
A 2005 report by the Better Hearing Institute stated that “In a survey of more than 40,000 households utilizing the National Family Opinion panel, hearing loss was shown to negatively impact household income on-average up to $12,000 per year depending on the degree of hearing loss” (Kochkin, 2007)
While we are all listeners, we must begin to realize that millions of us have difficulty effectively listening. The assumptions we have relied upon, ‘when I talk, people understand me, and when I listen, I understand what others have said’, need to be modified. Not everyone fully understands what I say, and I have to admit to myself that I might not fully understand what is being said to me. This can be a difficult paradigm shift to quickly implement but it is one that those of us who research, study, and teach listening must work hard at.
For those of us with a listening disorder, we must make it clear that in order to fully understand what is being said, we must ask those that are speaking to speak slowly and clearly but without raising their voice. We truly want to understand what is being said.
Listening disorders are a fact of life, one that each of us, speaker and listener, must accept. We have to work at determining why someone cannot, rather than doesn’t want to listen and provide them with the tools to better communicate.
References
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JohnsHopkins Medicine. (2011, February 14). Hearing Loss and Dementia Linked in Study [Press Release]. https://www.hopkinsmedicine.org/news/media/releases/hearing_loss_and_dementia_linked_in_study
Kochkin, S. (2007). Untreated Hearing Loss on Household Income (p. 9). Better Hearing Institute. https://betterhearing.org/HIA/assets/File/public/marketrak/MarkeTrakVIITheImpactofUntreatedHearingLossonHouseholdIncome.pdf
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WHO (n.d.). Deafness and Hearing Loss, Key Facts. Retrieved November 21, 2020, from https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss
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