Auditory Processing Disorder (ADP)
What is APD?
Auditory Processing has been defined by APD pioneer, Dr. Jack Katz, as "What we do with what we hear." Our ears, when in healthy, undamaged condition, are like precision microphones. But in order for them to work as intended, they depend on the incredible processing of the central auditory nervous system (CANS) to receive their signals and convert them into meaningful, intelligible, and faithful reproductions of the sounds entering the ears. In effect, we ultimately "hear" with our brain, not our ears.Damage to the processor (the brain) will result in distorted, reduced-fidelity reproduction of inputs, no matter how intact they were leaving the transducer (the ear).
People whose conventional hearing evaluation indicates normal peripheral hearing at the ear-level have good "microphones." If they fail to experience quality sound perception–poor word recognition, difficulty extracting speech from degraded conditions (noise, poor acoustics, diminished-quality speech inputs), then the likely culprit is at the CANS level–the brain-stem or higher brain areas responsible for processing receptive auditory–specifically language–information. This is when a thorough central auditory processing (CAP) evaluation is recommended.
In the case of children, especially in their formative speech and language acquisition years, an auditory processing disorder (APD) can have disastrous effects on the appropriate development of auditory language, which can result in speech articulation problems, vocabulary and grammar problems, handwriting issues, and other problems. It logically follows that, since we reproduce what we "hear," disordered perceptions resulting from an APD will cause output errors in expressive language.
In some adults, APD may have been a factor most of their lives, just undiagnosed–especially in those who experienced significant difficulties in their educational history. Acquired APD can also result from head injuries, or acquired peripheral hearing loss (with resultant lack of auditory stimulation to the CANS areas), neurological disease, and from the normal processes of aging. Adults with pre-existing APD will frequently experience out-of-proportion hearing difficulty when their peripheral hearing becomes even marginally degraded due to aging or noise exposure. Research also indicates a significant increase in acquired APD among some menopausal women.
Other Significant Factors:
- Peri- or Post-menopausal women often develop symptoms of APD.
- Persons with traumatic brain injury (TBI) have high incidences of APD.
- Persons with persistent communication problems, but normal audiogram results.
- Adults who have children, parents or siblings with auditory, speech/language, reading, or learning problems, especially if they themselves experienced similar academic /developmental problems.
- Adults who experienced recurrent middle ear infections or a history of P.E. (ventilation) tube insertion(s).
- Adults who diagnosed with attention-deficit problems or dyslexia as students.
Symptoms of APD
The symptoms of APD are very similar to the symptoms of a peripheral hearing loss (a hearing loss caused by a problem in the ear itself.) Although the sounds are loud enough, the person has difficulty understanding the message, therefore acting like someone with a hearing problem.Following is a list of symptoms teachers and parents have often observed in children with APD.
Does the child...
- have difficulty with reading and spelling?
- have difficulty responding to part of the message?
- look around for visual cues from other children before beginning an assignment?
- have upper respiratory problems such as allergies, sinus, colds, adenoid problems, or mouth breathing?
- have a history of fluctuating hearing loss, ear infections, earaches, feelings of pressure in the ears, discharge from the ears, or a complaint of noises in the ears?
- ever seem confused about where sounds are coming from and have trouble locating them quickly?
- have difficulty telling the difference between words that sound similar, such as cone/comb?
- demonstrate unusual expressions or body postures while listening (e.g., facial expressions, turning or tilting of the head, turning the body)?
- respond fairly well in quiet situations but have great difficulty listening in noisy environments such as with the TV or in a noisy crowd or classroom?
- have difficulty remembering what is heard (e.g., names, stories, numbers, multiple directions)?
- have trouble saying certain sounds correctly or have delayed language abilities or knowing the meaning of words as well as other children of his or her age group?
- pay attention to sounds within the environment? Is there curiosity about sound and attempts to imitate sounds?
- seem to be able to associate certain sounds correctly with the source (e.g., siren with picture of fire engine)?
- often confuse directions or words and think something else was said?
- have difficulty associating letters of the alphabet with their sounds?
- perform more poorly on tests requiring verbal language understanding rather than a "hands on" test situation?
- seem to be slow to respond to auditory information, as if it takes longer to think through the information?
Adapted from Educational Audiology Association: Great Educational Handouts, Vol. 1, 1998. Developed by Gail G.Rosenberg, M.S., CCC-A, School Board of Sarasota County, FL. Reprinted with permission from the Educational Audiology Association.
Adults with APD: Symptoms and Considerations
The symptoms of APD in adults are very similar to the above listed for children. What is different for adults is that, since most have undiagnosed APD problems, they have, over time, developed coping mechanisms which may have compensated for some effects, or simply hidden–at least in part– the effects in others. A common hallmark associated with APD is difficulty listening in the presence of background noise or poor acoustical environments; however, the deficit may also be seen in one or more behaviors noted in the American Speech-Language-Hearing Association (ASHA) consensus statement on auditory processing disorders (ASHA, 1996): auditory discrimination, sound localization, difficulty understanding speech in competing noise and/or speech signals of degraded quality. Also recognizing auditory patterns and processing the temporal (time-based) elements of auditory signals can be impaired.
In addition to these deficits, commonly reported symptoms in adults with APD include:
- Lack of music appreciation/ aptitude
- Difficulty following conversation on the telephone
- Difficulty following directions (especially multi-stage)
- Difficulty following long conversations
- Difficulty taking notes
- Difficulty learning a foreign language or technical information where language is novel or unfamiliar
- Social issues—difficulty "reading" others/or being misunderstood by others as to intent or mood
- Difficulty with subtle meanings: sarcasm, subtle humor
- Having a "flat" affect to their speech which lacks appropriate stress and intonation patterns
- Spelling, reading, writing issues
- Organizational problems