When the Brain Can't Hear: Unraveling the Mystery of Auditory Processing Disorder

Teri James Bellis, Ph.d., is a professor of audiology at the University of South Dakota and the author of the authoritative text for professionals on the diagnosis and treatment of APD. Ironically, she herself became the victim of adult-onset APD as the result of head trauma suffered in a car accident.

Her writing has been featured in numerous medical and academic publications, including the prestigious Journal of Neuroscience. She lives in South Dakota.

Chapter One

The Many Faces of APD

Jeff was seventeen years old, over six feet tall, and outweighed me by at least a hundred pounds. He was a big kid. Tough, too. He was one of the starring offensive linemen on his high school football team. Word had it that he could cut through the other team's defense like a knife through butter, scattering smaller players in all directions.

Yet, despite all of his toughness, he had a gentle, polite manner and a heart of gold. When Jeff and his mother arrived at the clinic, he greeted me with a shy smile. He was extremely cooperative during testing and apologized whenever he made a mistake or missed an item. He even called me "ma'am." I'm not too fond of that generally, but, coming from him, I found it quite endearing. Which is probably why I felt as if my heart were breaking when, halfway through my explanation of his test results, he dropped his head onto his folded hands and began to cry.

My voice stuttered to a stop. I laid my hand lightly on Jeff's shoulder, and he grasped it in his large, meaty palm and squeezed.

In a choked voice, he whispered, "I thought I was just stupid."

"What do you mean?"

He lifted his head and met my gaze. There was relief in his eyes, but also anger, embarrassment, and just a little defiance.

"You know, dumb jock. I just always figured I was stupid. That's why I couldn't get it. I was just a big, dumb jock. A joke."

These were astounding words coming from a boy who had just been elected "most popular" in his junior class and was a sure bet for prom king in his senior year.

Jeff had experienced academic difficulties ever since he had begun school. He had had problems learning to spell and read and still struggled with those subjects in his junior year in high school. He liked the idea of losing himself in a book, of journeying to far-off lands or reading about historical people, but he rarely opened a book unless forced to. Jeff had a difficult time sounding out the words, so his reading was slow and laborious. As he described it, by the time he figured out what the words were, he had lost the thread of the story.

But Jeff loved to spin tales. He would make up stories about princes and dragons, life in the circus and travels to outer space, and tell them to his younger brother, who would sit spellbound in wonder as the stories unfolded. Creative as he was, Jeff never wrote his stories down. As with his reading, spelling was a struggle, so much so that even if he focused on telling the story and just coming close enough to the spelling of the words so that he could return and correct them later, he was unable to understand his own writing when it came time to polish what he had set to paper. As a result, his English composition and creative writing papers were short, poorly organized, and contained only simple language and elementary vocabulary. They exhibited no hint whatsoever of the imaginative mind of the boy who held the pen.

Jeff came from a rural school district, and special education services were scarce. Nevertheless, during his elementary school years, he did qualify for reading remediation and tutoring under the classification of learning disability. Since junior high school, however, he had not received any services, primarily because he consistently earned A's and B's in all of his classes. Therefore, the school-based special education team had decided that his reading problems were no longer affecting him academically.

f0

The reason for Jeff's apparent educational success was, unfortunately, all too common. As a student who excelled at football in a town where football was all-important, he had been passed through every class since he was in the ninth grade. No academic probation or C's for our boy, no, sir. In fact, his good academic record, combined with his amazing sports ability, had already resulted in offers of full-ride sports scholarships from several major universities -- before he had even begun his senior year in high school.

Any other kid in his shoes would have been turning cartwheels.

But Jeff was different. He was acutely aware that he hadn't earned the grades he had been given. In fact, despite putting several hours into his studies every night after football practice, he knew that he should, by rights, barely be passing subjects such as social studies, history, and English composition.

His mother had initiated Jeff's referral to me for central auditory processing evaluation. Because she saw Jeff still struggling so hard with reading, she had arranged for independent, private testing by a specialist in learning disabilities. This testing had confirmed that Jeff exhibited low average to borderline abilities in reading decoding (e.g., sounding out words, or word-attack skills), general fund of knowledge, and auditory discrimination abilities. Other symptoms leading to the suspicion of auditory processing deficit were his difficulty following information presented in lectures and, particularly illuminating, his inability to hear the quarterback of his football team call plays during the huddle. "I can't ever hear him," he told me. "But I don't let on. I just keep my eye on where the ball is. I know what I'm supposed to do, so I just go out there and do it." In this manner, Jeff had succeeded in football without anyone being aware of what he had secretly come to call his "hearing problem."

In social situations, he frequently smiled his shy smile and nodded rather than jumping into the conversation, furthering others' perception of him as the sweet, strong, silent type. And when he was unable to answer questions posed directly to him or answered as if he hadn't been paying attention, he took the ribbing of his friends -- still with the same, shy smile.

But inside Jeff was hurting.

"You're not stupid, Jeff," I told him. "You never were. You have what we call an auditory processing disorder. Basically, what this means is that your hearing itself is fine, but what gets into the ear somehow gets jumbled by the time it gets to the brain. Because of this, different letters may sound the same to you, making it hard to tell the difference between different speech sounds. Or you might hear what someone is saying, but it's distorted or muffled, like the person is mumbling, especially if there's a lot of noise around. If you can't hear the speech sounds clearly, it's hard to learn how to sound out words when you're reading or to spell them when you're writing. That's why you have to work so hard." With that, Jeff released my hand, nodded once, and listened while I explained the rest of the test results and what I thought we should do to help him overcome his disorder. A disorder that had a name for the first time. One that could be addressed, confronted, and although maybe not completely fixed, one for which he could at least learn ways of compensating.

That was when Jeff shared his dreams for the future with me. It wasn't enough for him to be popular, to be a football star, and to have a college education virtually handed to him on a platter. It wasn't enough that there was already talk of his possibly not needing to finish college, of being picked up by a farm team or even a pro team before he even reached his senior year at whatever university he chose.

Jeff had bigger plans. "I'm happy about the whole scholarship thing, sure," he admitted. "I mean, that'll get me there, pay for everything. And I like football. It's fun." He shrugged. "But I really want to do well in college. I want to learn. I don't want to be a football player for real, not after college. I mean, that's not what I want to do with my life."

"What do you want to do with your life?" I inquired gently.

He dropped his head just a little, almost apologetically, and color rushed to his cheeks. "I want to be a lawyer," he said, very, very quietly. "Like my dad."

And at that, his mother began to cry, too.

Jeff was facing a unique set of difficulties. On the one hand, he was virtually assured a college education. On the other hand, for him to reach his goal, he would have to actually perform in college. Football might get him through with a general liberal arts degree, but to be a lawyer he would have to go beyond that. He wouldn't be able to hide behind the misguided, albeit well-meaning, protection of his coaches or teachers. He would have to meet high academic expectations just to get into law school, then perform at an even more advanced level to succeed once he was accepted. He wouldn't be able to rely on his good looks and charming personality.

Jeff was aware of all of these things. Just as he was excruciatingly aware that his problems with reading and writing -- his "hearing problem" -- would pose substantial barriers to his ever being able to meet those expectations.

But at least now the disorder had a name. He could take comfort in the fact that he wasn't stupid as he had always feared. Instead, his difficulties had a very real physiologic cause. And we had agreed on an intensive plan of attack, including therapy techniques, environmental modification suggestions, and ways for him to compensate for his difficulties. When he left my office, he was once again smiling. This time it was a smile full of hope.

After intensive computer-based therapy, Jeff's reading decoding and auditory discrimination skills improved significantly. Acknowledging his disorder and giving it a name helped him to gain confidence in himself and his abilities. So, too, did teaching him to become an active listener and providing him with strategies to compensate for his disorder. Right now, Jeff is a sophomore in college, majoring in political science and playing football on a full-ride scholarship. He receives some special accommodations related to his disorder through the university's office of disabilities services, and he is earning solid A's and B's.

It wouldn't surprise me at all if Jeff did, indeed, finally make it to law school.

Jeff's story is somewhat typical of the children I see with APD. Many of them complain of difficulty with spelling and reading, inability to understand what is being said especially with noise in the background, and inner feelings of inadequacy and ignorance. Children with APD gradually become aware that something is wrong because they find themselves having to work so much harder at certain tasks than their friends do. Many children with APD, like Jeff, perform near enough to the normal range in school to disqualify them for special services. However, even those children who achieve some academic success usually come home from school at the end of every day exhausted from having to spend so much effort just listening. Then they are faced with several more grueling hours of effort to finish homework that might take their friends less than half that time to complete. Over time, they may learn to compensate to some degree for the disorder. But many children with APD continue to have problems into adulthood, especially if the disorder goes undiagnosed and untreated.

Also like Jeff, many children with APD become masters at hiding their disorder. In their early years, they may try to participate in conversations or classroom discussions; however, because their input is frequently off-topic or shows a lack of comprehension of the topic, they may be ridiculed, laughed at, or -- even worse -- simply ignored. After years of this, some children simply withdraw from communication altogether. Some become sullen and sit in their chairs with arms folded and hands fisted, belligerent scowls on their faces, daring anyone and everyone to attempt a connection. But this is merely a mask that allows them to protect their vulnerable, hidden inner selves and to retain some semblance of power over the daily situations in which they feel powerless. Although this frequently leads to social isolation, it is a self-imposed isolation and appears far more preferable and less humiliating to the child than the inevitable overt exclusion by others that they have experienced throughout their lives.

Others, like Jeff, continue to participate in life, to accumulate friends and join in extracurricular activities. This is particularly true for those children who exhibit some special talent in other areas such as sports, music, art, or theater. This special talent gives them an outlet for their need to connect with others while, at the same time, providing them with at least one environment in which they feel safe and can succeed. But even these children must deal with the frequent, and often unintentionally cruel, barbs from friends and teachers, the perception of them as somewhat "slow," the teasing that accompanies their frequent social and communicative faux pas -- "Jeez, what are you, stupid or something?" So they, too, wear a mask of smiling tolerance and become the "good buddy" who'll put up with anything. And they frequently withdraw in their own way, becoming quiet followers in the parade of life, seemingly happy, sometimes even popular, but, all the while, bleeding inside.

CLAY: SEVERE APD IN A PRESCHOOLER

When he was really little, just a baby, Clay made all the same sounds that his sister made. We kept waiting for that first word to just pop out. But it never did. At first we thought, "Well, maybe it's because his sister is talking for him. I mean, she really does talk a lot." But he's four now. Four years old. And he doesn't understand us, and we don't understand him. Sometimes, when he's frustrated because he isn't getting what he wants, he just screams and screams and screams. At first they said he was autistic, then they said he was retarded. Now they just don't seem to know at all. We're starting to use sign language with him. What do you think? I'll learn sign language, I'll use it if that's what it takes. I just want to be able to talk with my baby. You know, sometimes I feel like screaming, too.

-- Clay's mother

When I first saw Clay, he was four years old and had been in speech and language therapy for two years. His therapists and parents were working on basic skills such as teaching Clay to respond consistently to his name, repeat simple consonant-vowel syllables with visual cues, maintain appropriate eye contact, and follow simple commands. They were also augmenting his speech-language therapy with sign language, which he was beginning to pick up and use. The speech-language pathology supervisor, Sue, pulled me into the observation room one day to observe a therapy session. Except for his language development, everything about Clay argued that he was a normal little boy. He was curious, exhibited good motor skills, and played appropriately with toys. For example, when playing with a toy farm, he would place the farm animals where they belonged in their stalls or walk the little plastic cows around the pen outside the barn. He could put together puzzles, build things with blocks, and make toy airplanes "fly." He was affectionate and giggled when something amused him. Because of these behaviors, Clay's mother and Sue didn't think Clay was autistic or retarded. Beyond that, however, they had no idea what was causing Clay's speech and language delay. A developmental pediatrician had ruled out any medical or pathological cause for the delay, as well.

But Clay had virtually no receptive (understanding) or expressive (output) language. He was simply, in our terms, a "nonverbal child." He did not turn his head when his name was called. He did not follow even simple directions or answer questions like "How old are you?" or "What's your name?" He didn't name pictures in a book. He communicated only by gestures, grunts, and unrecognizable gibberish. He did not seem to have the basic understanding that speech has meaning and is important. As a result, he rarely even looked at the person who was talking to him.

When I observed Clay for the first time, I was struck by how similar his behavior was to that of a deaf child. He rarely responded to his name. He occasionally repeated portions of words or syllables, but he was neither consistent nor accurate with this skill. For example, if the speech-language pathologist said pig and pointed to a picture of a pig, Clay might respond with ik, ig, just the vowel itself, or nothing at all. On the other hand, when looking directly at the therapist and watching her mouth emphasize the p sound, complete with a dramatic release of air (which made him laugh), he would say "pig." But his spontaneous expressive communication consisted solely of grunts, points, and, as his mother described, screams when he was displeased.

Clay wasn't deaf. In fact, his hearing sensitivity was well within the normal range. He had been tested using what we call conditioned play audiometry -- a test in which the child drops a block into a bucket in response to sound. By teaching Clay to drop a block whenever he heard beeps or tones of different pitches and loudness, we were able to determine the quietest sounds he could hear -- or his hearing thresholds. We had obtained a complete audiogram, a graphic representation of Clay's thresholds from the low pitches all the way up to the high pitches. His hearing was entirely normal in both ears. Therefore, although he behaved precisely as we might expect a deaf child to behave, hearing loss was not the cause.

Yet, watching Clay that first time, I was convinced that, despite normal hearing sensitivity for tones, he was, for all intents and purposes, a deaf child.

Because of Clay's young age and lack of expressive abilities, we were unable to perform standard tests of auditory processing function with him. These tests require a mental age of seven or eight years, and the ability to repeat things such as numbers, words, and sentences. Diagnosis of APD is very difficult in children younger than about seven; however, there are other ways of determining how well a young child's auditory system and brain are able to cope with sound. One of these procedures uses auditory electrophysiology. For these tests, small electrodes are taped to various locations on the child's head, sounds are fed into the child's ears, and a computer screen records the brain's response to the sounds. The child must sit very still or be asleep for this testing. Unfortunately, deep sleep may abolish some of the responses from higher cortical regions of the brain that are dependent on consciousness. To get an active four-year-old to sit still while electrodes were applied to his scalp and sound was presented to his ears, I had Clay lie back in a chair with his mother and watch a favorite video. Because we were looking at brain-related responses to sound that don't require any conscious listening on the part of the child, the video did not interfere with the testing in any way. We obtained a clear picture of what we call the neural representation of sound from various portions of Clay's central auditory nervous system.

Results of Clay's testing indicated that the lower parts of his central auditory system, such as his brain stem, responded exactly as they should to sound. However, as we moved higher in the nervous system, the responses to sound began to diminish. Finally, at the level of the brain itself, or the cortical level, Clay's responses to sound were extremely reduced, especially over the left hemisphere of his brain, where actual speech-sound processing takes place.

All of this suggested that Clay exhibited a condition affecting basic neurophysiologic representation of sound at the cortical level of his brain. Although his young age may have affected these findings to a degree, that he was awake and alert during testing, combined with the presence of some response over the right side of his brain, was conclusive, physiologic evidence of an auditory processing deficit. In essence, although his ears were fine, his brain couldn't "hear" certain sounds.

"So he's deaf, after all?" his mother asked after the testing, some relief in her voice. This was not surprising because, as frightening as the presence of deafness in a child may be for a parent, at least such a clear-cut diagnosis would be understandable and would provide a definitive reason for Clay's speech delays. Even a diagnosis of deafness might be preferable to the endless lack of closure and understanding that results from never knowing why a child is having difficulties.

"No, not exactly," I explained. "He's not deaf in the traditional sense. In fact, his ears are functioning just fine. He hears sounds. He knows when the phone is ringing or someone is knocking at the door. He responds when the dog barks. He can hear your voice and it comforts and calms him. The problem is in the way his brain deals with sounds. It's probably hard for Clay's brain to interpret most of the sounds of speech. Even though he can hear someone talking to him, he can't really tell the difference -- or discriminate -- between the speech sounds themselves. He might hear everything muffled, like he's underwater. Or some speech sounds might sound just like others to him. He might not even truly understand that speech has meaning. It might all just be noise to him -- like the dog barking or the knock on the door. That's why he doesn't understand what's said to him. It's also why he doesn't speak clearly, because our ability to speak is closely tied to our ability to hear."

"It's because he had so many ear infections when he was a baby, isn't it?" Clay's mother asked. "The doctor told me they wouldn't affect his development, but I was always worried about them."

I explained that, although a link has been shown between a history of early, chronic ear infections and auditory processing problems in some children, there was no way of knowing how much these infections had contributed to Clay's difficulties. Certainly, if ear infections occur frequently enough at a very young age, the child often misses some of the speech and language input during those periods that are critical for language development. On the other hand, many children have a history of severe ear infections throughout their childhood and exhibit no lasting effects whatsoever. Furthermore, for many children, ear infections may be "silent" -- that is, without evidence of pain or fever -- and thus go undetected for a long time. In these children, it is difficult to determine in hindsight to what degree the infections may have affected the child's language and learning.

We simply do not know why the vast majority of APD cases occur. That is one of the hardest things for a parent of a child with an APD to accept: the realization that the underlying cause, the why of it all, will likely never be identified. We do know, however, that many cases of APD are present very early in life, probably at birth. They don't just develop suddenly, unless the child has had some type of head injury, illness, or other trauma that can affect brain function.

Over the summer, Clay underwent intensive auditory training, both computer-based and interactive, focusing in tandem on both discriminating (telling the difference between) and producing (speaking) speech sounds. Most of these games required Clay to imitate consonants, vowels, syllables, and words presented by animated characters on a computer screen. When he responded correctly, the characters rewarded him with music and dancing. By the end of the summer, his ability to imitate syllables, words, and even short phrases had improved remarkably. His spontaneous expressive vocabulary began to increase as well. When he returned to the clinic in the fall after a short hiatus, he surprised all of us by greeting me in the hallway with the words, "Hi, teacher."

When I wrote the first draft of this chapter, Clay's story stopped here. I knew that Clay's student clinicians would continue to work with him on speech and language production as well as auditory skills during the fall semester. I knew that some progress would be seen, but I couldn't predict just how far he would go or whether he would ever exhibit normal speech and language skills. However, those two words -- "Hi, teacher" -- had given us all reason to hope.

Near the end of the fall semester, Sue once again pulled me into the observation room to watch a therapy session. On the other side of the one-way glass, I saw Clay and his clinician playing a game that used blocks and action cards to help put words in their correct order in sentences. I watched as Clay spontaneously produced four-word sentences, imitated eight-word sentences, and laughed and chattered with the clinician, clearly enjoying his newly acquired ability to communicate.

Just a few short months ago this child had been virtually nonverbal. Now, for the first time, Clay was able to communicate his true nature. Witty, affectionate, funny, and bright, his delightful personality shone through in his words and actions. It was as if he had finally become aware that sound had meaning, and because of that awareness, the floodgates had opened, allowing language to flow through him. We stood in the darkness -- Sue and I -- watching this miracle and cried. And we thought, "This is what it's all about. This is why we do what we do. One child like this -- just one -- makes everything we do worthwhile."

A few weeks later, I reevaluated Clay's brain responses to sound. They looked entirely normal for a four-year-old child. He still needed therapy to improve his pronunciation -- or articulation -- of speech sounds and to build his language skills. But his accomplishments in a very short period of time were nothing short of remarkable.

LARRY: MILD APD IN AN ADULT

Not all people with auditory processing deficits exhibit obvious and severe difficulties during early childhood. In some cases, APD does not manifest itself until much later in life and, even then, sometimes not until the conditions are precisely right:

I never had any problems in school. Not that I was a star student or anything, but I got by just fine. Got my MBA, but after a few years in the corporate world, I got bored. Guess I needed more action. I'd done some investing over the years, mostly on-line, and I thought the whole stock market thing was fascinating. So I went for it. During our training, we were allowed to go down onto the trade floor -- what an exciting place! I couldn't really understand a lot of what was going on, but I figured that I just had a lot to learn. When it came my turn to take my spot on that floor, I was really nervous. People were waving papers and yelling things at me. I couldn't understand anything. My boss told me that it wasn't unusual for someone to freak out the first time or two they're in the action like that. But the problem wouldn't go away. I've got all the skills, I know what to look for, I know how and when to trade, damn it! But, down there, when they're all yelling at me like that and I'm supposed to react fast, I just can't do it. I can't seem to make sense of all the noise and the chaos. They pulled me off the floor and I'm at a desk job now. They're even talking about firing me. I've never been fired in my life! I really thought I'd like this field, really looked forward to being where all the action is. But how will I ever know if I can't even do it, if I'm stuck behind a desk? I might as well go back to corporate management.

-- Larry

Larry was referred to me by his employer after another audiologist had determined that his actual hearing acuity was normal and suggested the possibility of an APD. By the time I saw him, he was frustrated and somewhat defensive because of the treatment he had been receiving lately from his supervisor. Although his boss had been understanding at first, Larry was now becoming a liability to the company and was on the verge of being fired. He was forty-three years old and was looking at being unemployed with a wife, two children, and a house in the burbs. It was a potentially volcanic situation.

Larry's testing revealed a very mild auditory processing deficit specifically in his ability to "fill in" missing pieces of a message -- a process we refer to as auditory closure. He also had difficulty with messages in general when they were presented in competing conditions, such as when different information was given to each ear at the same time. It was unclear whether Larry had had this mild disorder all of his life or if it was adult-onset. What was clear was that his deficit was so mild that it would have been no more than an occasional, mild annoyance in typical situations. The only environments in which Larry would have noticed his mild deficit would have been those where the background noise level was extremely high -- such as on the floor of the stock exchange.

Larry's case illustrates that even a very mild auditory deficit can nevertheless be extremely disruptive depending on the unique circumstances of a person's life. Larry would have been successful in virtually any other job, as he had proven prior to his career change. However, when he paired his auditory deficit with the unusual and extreme auditory demands of working on a trade floor, he was unable to perform. Larry couldn't have made a worse career choice given his particular auditory disorder.

Larry was forced to accept that he could never compensate sufficiently for his mild deficit to be able to perform in an environment like the stock exchange. He has moved back to the corporate business world and, last I heard, was doing quite well. But I am sure he still thinks occasionally about the color and excitement of the world he left behind.

Larry's situation brings to light one unfortunate but very real factor that must be considered in any discussion of APD. Although treatment may remediate the disorder, some residual difficulty may well continue for the remainder of the person's life. When we develop a management program for APD, we address these issues and suggest methods of compensating for the residual disorder as well as strategies for changing the listening environment to make it more friendly for the person with APD. However, even with such strategies in place, the individual may simply have to accept that he will have difficulty in some situations. This was precisely the case with Larry and the stock exchange. The very nature of his job setting made any environmental changes impossible and rendered his compensatory strategies virtually ineffective. He was forced to make a realistic life choice -- to change his job setting entirely.

Individuals with APD must realize that, just as with other disabilities, some activities will continue to be difficult or impossible, depending on the severity of the disorder. Although we do not wish to dampen anyone's dreams or to encourage individuals with APD to limit themselves unnecessarily, we must also be practical. When one considers the frustration and self-flagellation that is almost unavoidable when one sets unattainable goals and continually, without exception, fails, then perhaps it is time to choose a different objective, one that is no less enticing but is more likely to be within reach.

JASON: RIGHT-HEMISPHERE DISORDER AND APD

All three of the cases presented thus far have focused on the effects of auditory processing disorder on the perception of speech sounds. The dysfunction could be localized, generally, to the language-dominant (or left) hemisphere of the brain, where speech-sound analysis and representation takes place. However, not all auditory processing disorders arise from left-hemisphere dysfunction. Nor do all auditory processing disorders affect the perception of speech per se. The auditory manifestations of dysfunction in the right side of the brain can frequently be just as pervasive, and harder to pin down, as those of left-hemisphere dysfunction. Furthermore, in many cases, right-hemisphere dysfunction can lead to other disorders and difficulties that have a devastating impact on the individual's social, communicative, and psychological well-being:

Jason doesn't have any friends. I mean that. No friends at all. No one likes him. He doesn't do anything that I see other little boys do. He doesn't like puzzles, never played with LEGOs or blocks. Half the time, he just sits there. It's like he's drugged or something. We try to joke with him, but he just looks at us with that stony face -- like a robot. Sometimes he'll laugh a little, like when he's watching a Three Stooges movie or something. I love it when he laughs. But most of the time he just seems so depressed. He does all right in school, and all of the testing says that his learning abilities are normal, that there's nothing wrong with him. So they won't even do anything. They just said that he has emotional problems, like his brothers, and leave it at that. Maybe it's us, maybe we've done something wrong. You know, his older brother is in a special home for kids with emotional problems. And his oldest brother, well, you probably already know about him from the report. I don't know. I just don't think I can take this anymore. What are we doing wrong?

-- Jason's mother

Jason was a handsome little eight-year-old boy. He lived in a small state where no auditory processing services were available, and I was brought out to assess several children suspected of auditory deficit. Jason was a last-minute addition to my assessment list. His referral to me resulted less from any obvious auditory difficulty than from desperation on the part of the private psychologist working with him to uncover any information at all that might help explain this enigmatic child. Unlike with most of the children I assess, I hadn't had much opportunity to review Jason's records, and frankly, I was a little unsure as to the appropriateness of the referral. Despite my misgivings, I agreed to test him.

The little information I had been able to glean from his records indicated no obvious learning or language difficulties. The speech-language report did say, however, that he exhibited mild pragmatic concerns -- or concerns regarding his use of language, particularly relating to social communication. Jason didn't seem to understand quite what to do or say in a social situation. He might interrupt or show other signs of inappropriate turn-taking behaviors. Although his contributions to a conversation were generally related to the topic of discussion, he would stray from the key point and end up talking about something that really wasn't the focus of the conversation. For example, during a conversation about endangered species, Jason might begin talking about the bald eagle, but somehow work his way around to a discussion of his pet cat. He often failed to laugh at jokes, overreacted to perceived insults or sarcasm, and ignored social conventions such as making expected responses to salutations ("Hello, how are you?" "I'm fine, thank you. How are you?") or saying good-bye appropriately ("It was good to see you. Have a nice day").

Furthermore, his speech-language pathologist stated that Jason's expressive speech was not abnormal exactly, but was a little, well, unusual. She couldn't quite put her finger on it, but his rhythm and cadence were subtly wrong somehow. Just a little off in some indefinable way. He didn't speak in a monotone exactly, but he didn't seem as animated as most boys his age. More obvious was his lack of facial expression. This latter finding was also characteristic of depression, something that was prevalent in Jason's family. Both of his older brothers had been diagnosed with depressive disorders. The middle boy had attempted suicide when he was ten years old and was currently living in a group home for children with emotional disturbances. The oldest boy, tragically, had killed himself at the age of fourteen.

Jason was under the care of a psychologist when I saw him, but he wasn't receiving any special services in school because he didn't exhibit any documented language or learning deficits that would qualify him for special education in those areas. He wasn't great at math, but fell loosely within the low end of the normal range. His nonverbal IQ scores were lower than his verbal scores, but not significantly so. He was, however, classified as emotionally disturbed and received some accommodations in the classroom due to that.

During testing, Jason offered none of the chitchat that typically accompanies my evaluations with children, even though he understood all of the directions easily and was entirely compliant. On some of the testing, Jason performed just fine, well within the normal range for his age. Yet he had a good deal of difficulty with certain tasks when competing messages were delivered to both ears at the same time. More revealing, he could not perform at all during a task that required him not to repeat speech sounds, but to perceive subtle pitch and duration differences in sequences of tones or beeps. This required the right side of his brain to hear the pattern, or acoustic contour, of the tones. Jason understood the task, could describe the patterns easily when the differences between stimuli were large or when I "sang" them in my own voice. But when the differences were subtle, he reported that the tones all sounded the same.

This pattern of performance indicated an auditory processing disorder, but Jason's specific type of APD was not in discriminating speech sounds or other "left-brain" auditory skills. Rather, his difficulty, like my own, was in those "right-brain" auditory abilities that are responsible for perceiving nonspeech or "musical" aspects of the signal, including those cues that convey tone of voice and assist us in understanding what is meant in relation to what is said. People with this type of auditory disorder frequently misunderstand the intent of others' communications, often complain of hurt feelings, and may themselves speak in a monotone or with little expression. Often, the cadence or rhythm of their expressive speech is somewhat distorted, as was Jason's. This type of deficit may affect a person's ability to appreciate humor or sarcasm, to engage in socially appropriate conversational exchanges with others, and to "read between the lines." These abilities come naturally to most, and they help to make communication the many-layered, enjoyable activity it usually is. But for a child or adult with right-hemisphere-based APD, communication is far from enjoyable. It can be a painful, frequently embarrassing, or confusing experience.

And yet, Jason's auditory processing deficits were, without question, the least of his concerns. My testing had uncovered merely the auditory piece of what was clearly a more global right-hemisphere deficit that affected Jason's functioning in many other areas. Jason's symptoms made me suspect a disorder that is sometimes referred to as nonverbal learning disability or NVLD. NVLD can lead to a wide variety of symptoms including social difficulties, depression, difficulty with nonverbal tasks (including math calculation and visual-spatial activities), expressive and receptive prosody (or tone of voice) difficulties, allocation of attention, and the like. All of these symptoms appeared to be present to some degree in Jason's case. Certainly, however, his depression was of primary and immediate concern, particularly given his family history. It is possible that Jason's depression was exacerbated by his lack of success in socialization and communication. But because depression frequently co-occurs with right-hemisphere dysfunction, it is difficult to determine just how much of Jason's emotional difficulties were linked to his auditory processing deficit.

I referred Jason to a university center where cutting-edge research into NVLD was being undertaken. They confirmed other, more subtle diagnostic indicators of right-hemisphere dysfunction, such as that Jason exhibited a lesser degree of visual scanning to the left of center as compared to the right of center as measured by infrared tracking of his eye movements. Auditory and related testing eventually completed on Jason's older brother revealed the same pattern.

Jason is currently undergoing therapy for both visual-spatial abilities and auditory perception and production of prosodic aspects of speech. He and his brother are being closely monitored by a team of psychiatrists, and trials with antidepressant medication have been initiated. When he entered the fourth grade and the learning demands increased, Jason began to exhibit clear difficulties in mathematics, so he is now receiving special services for these and related academic difficulties.

I don't know that it's accurate to state that Jason exhibits a primary auditory processing disorder. Certainly, his performance yielded clear patterns consistent with an APD; however, this was just one small factor contributing to Jason's overall difficulties. Of far more concern were the emotional and psychological manifestations of Jason's, and his brother's, right-hemisphere involvement. Importantly, the results of central auditory testing provided information that allowed us to explore further, and ultimately uncover, the underlying problem.

I also don't know to what extent therapy will be effective for Jason's difficulties. Most of the research into auditory and related therapy efficacy has focused on speech-sound training and left-hemisphere disorders. I hope that he can learn ways in which to compensate for his difficulties. I also hope that psychiatric and pharmacological interventions will address his emotional and depressive disorders sufficiently. But Jason may always have some difficulty judging communicative intent and comprehending the subtle, prosody-related, and social aspects of communication.

Jason's situation emphasizes some important principles of APD that should be understood. First, not all auditory processing disorders are speech-sound related. A person may be able to tell the difference between speech sounds well, be able to spell and write fluently, yet still exhibit auditory processing problems. More important, even if a child exhibits a clear auditory processing deficit, that deficit may not be the only, or even the most important, factor contributing to his or her learning or communication problems.

Many disorders either mimic APD or can coexist with APD, such as attention-deficit/hyperactivity disorder (AD/HD), autism, NVLD, and similar conditions. Confirming the presence of an APD in these cases is important; however, the diagnosis of an APD as a coexisting condition should not be taken to mean that all of the individual's difficulties can, therefore, be attributed to the auditory disorder. Instead, it is more often the case that the auditory disorder is merely one piece of the overall picture. As in Jason's case, APD may not even be the most important piece when one considers the individual as a whole. We must consider auditory processing in the context of larger, more global disorders that can affect a person's daily life skills and coping strategies in a variety of ways.

Furthermore, as Jason's case illustrates, APD diagnostic services may not be available in a given geographic locale. In recent years, the increased attention and education devoted to APD has resulted in increased APD services throughout this country and abroad. However, not all audiologists are educated or trained in diagnosis or management of APD, nor should they be expected to be. APD requires a specialized degree of expertise that goes beyond that provided in our typical audiological training programs.

EVELYN: APD IN THE ELDERLY

If it hasn't already been apparent, it should be pointed out that all of the preceding stories have dealt with males. Auditory processing disorders like learning disabilities, occur in males more frequently than in females, but they can and do occur in females. Furthermore, although the cases discussed so far have exhibited normal hearing sensitivity, auditory processing disorders can coexist with hearing loss, which can make management of the hearing loss more difficult:

Don't like them. Take them away. I can't hear any better with the dang things than I can without them. Everything's just noise. Noise, noise, noise. Gives me a headache trying to make sense of all that noise.

-- Evelyn

Evelyn was a small, white-haired, seventy-four-year-old woman who had absolutely no compunctions about expressing her true feelings. She had a pretty typical age-related hearing impairment that led to difficulties understanding speech, especially in noise or at church. She had recently been fitted with hearing aids in both ears after finally being convinced by her daughter-in-law to do something about her progressive hearing loss.

But the hearing aids didn't seem to help Evelyn. Nothing did. Whether she wore her hearing aids or not, Evelyn complained that she still couldn't understand what people were saying. The problem, she insisted, wasn't hearing, it was understanding. The hearing aids just made everything louder, not clearer.

Evelyn was referred to me because the standard hearing testing done before she was fit with hearing aids didn't explain why she was having such significant difficulties. In fact, her ability to hear and understand words was quite good when she was tested one ear at a time using headphones. This suggested that Evelyn would be an excellent candidate for binaural amplification -- hearing aids in both ears. Although some tests of auditory processing require that the listener's hearing be normal, some do not. I administered those central auditory tests that were appropriate for people with hearing impairment to get an idea of what other factors, not related to Evelyn's hearing loss, might be contributing to her listening difficulties.

Evelyn had far greater difficulty than other women her age during tasks in which competing messages were delivered to both ears at the same time. She also had difficulty with the tonal patterns tests described in the previous case, but unlike Jason, she could hear the differences among the stimuli just fine and was able to hum them with the conviction of a church choir leader, which, incidentally, she was. She could not, however, label or verbally describe them (e.g., high-high-low or long-short-long) when asked to do so. Memory was not an issue here. Evelyn was, and still is, sharp as a tack and can repeat entire strings of numbers or words on demand, as long as the numbers or words are presented in noncompeting conditions. No, Evelyn's difficulties stemmed from the fact that these dichotic listening and tonal patterns tests relied on the ability of both hemispheres of the brain to communicate with one another.

Recent research into auditory processing and aging has indicated that the ability of the two hemispheres of the brain to cooperate -- interhemispheric integration -- decreases significantly as we age. Furthermore, the data suggest that this integration deficit, if sufficiently pronounced, may well affect our binaural listening abilities, including the benefit we receive from binaural hearing aids. Evelyn's pattern of findings on central auditory testing confirmed that she exhibited just such a pronounced integration deficit. As she had insisted, the problem really wasn't her hearing. It was her ability to understand -- especially when both ears (and therefore, both hemispheres of her brain) were being forced to work together.

Although most people do hear better with two hearing aids -- a situation that most closely resembles normal hearing -- we discovered that Evelyn heard much better when she wore only one hearing aid in her right ear. She returned the left hearing aid and marched away happily, right hearing aid in place and turned up good and high. It's a Sunday morning as I write this, and I'm certain that at this very moment Evelyn is singing happily in the church choir or listening to the minister's sermon, quite satisfied with herself that she hadn't paid for two hearing aids when she does just fine, even better, with one.

Evelyn exhibited a third type of auditory processing problem, one in which the issue is neither "left-brain" nor "right-brain," but rather the way in which the two hemispheres of the brain interact. This common type of APD occurs in children as well as adults. In Evelyn's case, most of her difficulty was auditory in nature. However, many people with this type of integration deficit have difficulty with virtually any task that requires cooperation between the two halves of the brain and may exhibit what are commonly called sensory integration issues. From an auditory perspective, not only may they have difficulty with understanding speech in noise and telling where a sound is coming from, but they may have difficulty in linking the "left-brain" speech sound and language functions with the "right-brain" tone-of-voice or prosodic cues, resulting in some confusion and miscomprehension of what is being said and meant. The auditory manifestations of integration deficit may be extremely disruptive, or they may be relatively mild when compared to the sensory integration symptoms. Therefore, once again, we must consider the whole person to determine the degree to which a given APD may be affecting someone's life, for it is this picture that should guide our treatment efforts.

IF A TREE FALLS IN THE FOREST:

DEBATING THE EXISTENCE OF APD

It is not always possible to demonstrate objectively the presence of an APD. In fact, in many cases of APD, physiologic tests such as brain scans, electrophysiology, and magnetic resonance imaging (MRI) fail to reveal any obvious structural or functional damage or dysfunction. This not only poses a difficulty for audiologists in diagnosing APD (particularly in the case of very young children who cannot yet participate in behavioral testing), but also leads to denial on the part of some medical and other professionals that APD exists at all. Tragically, the assertion "If you can't see it, it isn't there" has led some to conclude that APD, very simply, is not real.

If a tree falls in the forest and no one is around to hear it fall, does it make a sound? Although people love to debate the two possible answers to this question, it is not really a philosophical question at all. And there is only one correct answer.

The definition of sound is "a propogation of vibration through a sound-conducting medium." Therefore, unless the tree is in outer space or in a vacuum, in which there is no sound-conducting medium such as air, of course it makes a sound. That no one is around to hear it fall is completely irrelevant and, thus, should not even enter into the equation.

Case closed. End of discussion.

Still, some continue to debate this issue, just as some contend that, if no one is around to understand, test for, or treat auditory processing disorders, or if they do not show up on our brain scans or other physiologic tests, then they, likewise, do not exist.

On the face of it, this argument seems reasonable, logical even. Logical, that is, until we consider the limitations of current medical procedures and technology in detecting subtle abnormalities in function as well as structure of anatomical organs. The brain is highly complex, with infinitesimal biomolecular and neurochemical influences that shape the function of the nervous system. It is not at all surprising that physical evidence of specific damage or dysfunction is lacking for the majority of APD cases. Indeed, it would be more surprising if all of these difficulties had a clearly evident, easily defined underlying cause.

For years, professionals and scientists have looked for the specific physiologic causes responsible for such conditions as autism, schizophrenia, learning disabilities, mental retardation, language delays, dyslexia, attention -deficit/hyperactivity disorder, and many other disabilities. And for years, those visible, documentable signs have eluded all of us. But we continue to search. We don't simply refuse to acknowledge their existence.

Not so with auditory processing disorders. From the first proposal of the term APD to describe these hearing deficits in the 1960s, the existence argument has raged. Some have said that auditory processing deficits are merely a manifestation of a specific learning disability or attention deficit or language disorder. Some have said that the frequent coexistence, or comorbidity, of auditory deficits with these other disorders render them merely one characteristic of a larger, more global disability. Some have even said that there is no way in which an auditory-based deficit of any type can have the kind of far-reaching implications hypothesized by the pro-APD camp.

Many of these arguments have arisen, no doubt, from at least some degree of professional territorialism and defensiveness. After all, many professionals in the field of speech, language, and learning had been working with these difficulties long before they ever had a formal label. Why, now, after all these years, should we suddenly "invent" a new label for an old set of problems that may well just be manifestations of other disorders already understood and diagnosable?

When confronted with the existence argument from fellow professionals, I offer the following response derived from current research into APD:

• Some children and adults exhibit extreme difficulties in primarily, if not solely, the auditory modality that affect their day-to-day communication and learning abilities.
  
  
• For the majority of these individuals, hearing loss simply cannot account for their difficulties.
  
  
• These individuals exhibit specific patterns of findings on tests of central auditory function that precisely mirror those of known pathologies involving the central auditory nervous system and nothing else, which cannot be ignored or put down merely to coincidence.
  
  
• A growing body of evidence obtained from new technological measures of auditory processing is demonstrating that the neural representation of sound in the higher brain stem or brain pathways of many of these individuals simply is different from that of other, nondisordered individuals.
  

In short, the battle over the existence of auditory processing deficits has begun to abate under the pressure of such overwhelming evidence. Although it is still possible to encounter someone in the fields of medicine or psychology or education or speech-language pathology or even audiology who asserts, "APD doesn't exist, and even if it did, there's nothing we can do about it anyway," this statement is, thankfully, far less frequent today than even just five short years ago.

As more information becomes available, as more sharing of findings and ideas is fostered among professionals in many different disciplines, and as new technological advances continue to support the existence of auditory deficits that can, indeed, impact a wide variety of functional areas, it is my fondest hope that this futile debate will end.

In the meantime, if a tree falls in the forest and no one is around to hear it fall, does it make a sound? You bet.

You've met several people each of whom exhibited an auditory processing disorder that affected his or her life in vastly different ways. I hope that their stories have convinced you that not only are auditory processing disorders very real, but that they may occur in anyone, at any age, and may manifest themselves in various manners. The stories you have read do not even come close to representing all of the possible combinations of gender, age, central auditory findings, and impact on life skills that are possible. They serve merely to illustrate the heterogeneous, complex nature of the disorder.

In the early days of APD, a definition of auditory processing was proposed by Dr. Jack Katz of Buffalo, New York. He stated that auditory processing could be defined as "what we do with what we hear." Over time, we have tried to hone this definition, to render it scientifically more technical, to narrow it down to specific auditory mechanisms. Also, because of the difficulty in developing a precise definition of what APD is and what it isn't, we have argued endlessly over what to call it, and by the time this book goes to press, our label for this disorder may have changed yet again. But, despite our best efforts, the heterogeneous and interactive nature of auditory processing deficits has eluded our grasp so that no specific definition of or label for auditory processing and its disorders has successfully captured its true essence. Therefore, we now are witnessing a re-evolution in which we are acknowledging that auditory processing does, indeed, consist of "what we do with what we hear." In a sense, we have come full circle, but now we are armed with more ammunition with which to analyze and fight the beast.

However, despite our increased knowledge, our ever-improving tools and measures and tests, we still have much to learn. In truth, what we do not know about auditory processing far outweighs what is in our current realm of understanding. In this fascinating, frustrating, and complex area, we still have, in the timeless words of Robert Frost, "miles to go before we sleep."

Copyright © 2002 by Teri James Bellis, Ph.D.