AUDITORY PROCESSING DISORDER: When the brain can’t hear
In the book “When the Brain Can’t Hear”, author Teri Bellis, Ph.D. provides a parent-friendly, detailed and responsible discussion of Auditory Processing Disorder. Auditory processing disorder (APD) refers to a deficiency in one or more of these auditory behaviors: Sound localization and lateralization, auditory discrimination, auditory pattern recognition, temporal aspects of audition, auditory performance with competing acoustic signals, auditory performance decrements with degraded acoustic signals.
In the U.S. 12,000 babies per year are born with hearing impairments (making hearing loss the number one birth defect). The problem is that the brain begins to develop language centers immediately after birth, and historically about 75% of children with hearing impairments did not have the losses detected until age 2 or later. In response, The American Academy of Pediatrics issued a policy paper stating, “Significant hearing loss is one of the most common major abnormalities present at birth and, if undetected, will impede speech, language and cognitive development.” Most states have legislated mandatory newborn hearing screenings and now over half of hearing impaired children have their losses detected at birth.
Prevalence of Auditory Processing Disorder among Pre-K and School-Age Children:
Auditory Processing Disorder occurs with about 2-3% of children, although some professionals believe these figures are an underestimate, due to high rates of “co-morbidity” (or overlap) with other issues, including Attention Deficit Disorder (DSM-IV reports 3 to 5% of kids), Learning Disabilities (DSM-IV reports 2 to 10% of kids), Reading Disorder (DSM-IV reports 4%).
Assessment of Auditory Processes:
There are many different specific tests that are conducted by Audiologists: The newborn audiological screening, the audiological evaluation conducted when there is language delay, and the most thorough assessment when there are concerns about Auditory Processing Disorder, including:
- “Dichotic Listening” involves perceiving two different sounds presented to each ear (a task that requires the right and left hemisphere to integrate and share information).
- “Binaural Integration” involves the ability to perceive and combine separate messages (e.g., when listening to two different speakers).
- “Binaural Separation” involves listening to a message (e.g., from the teacher) while ignoring competing information (e.g., background noise from other students, environmental sounds, etc.).
- “Monaural Speech Processing” refers to the ability to perceive speech signals that have been modified or distorted (e.g., frequency changes).
- “Phonemic Synthesis” involves perceiving blended speech sounds in the correct sequences in words.
- “Temporal Processing” involves perceiving the timing of words within a message.
What to do:
A multi-modal approach is considered most effective for the management of Auditory Processing Disorder, including:
- seat the child near the teacher
- physically improve the acoustics of the class (e.g., place carpets to absorb echo, place cut tennis balls on the legs of chairs, use smaller sound absorbing partitions)
- use sound enhancement devices (e.g., F.M. auditory trainer)
- heavily stress the use of visual demonstrations
- speak in concise sentences
- use repetition
- speak clearly
- slow down the rate of speech
- request verbal feedback from the child (rather than assuming the child fully understands your directions)
- provide speech therapy (focused on decoding, dichotic listening, memory, etc.)
- teach the child to compensate (by perceiving context, sustaining eye contact, etc.)
- teach the child to assertively and confidently request help as needed