I. Definition
Central Auditory Processing Disorders (CAPD) are a deficit in
information processing of audible stimuli with no deficits attributed to
hearing or intelligence impairment. To put it simply, it is the inability
to attend to, discriminate, recognize or comprehend what is heard, even
though hearing and intelligence are normal. CAPD are more pronounced when
listening to distorted speech, or in poor acoustic environments such as
listening in the presence of competing background noise.
II. Identification
Behaviors of children who may have CAPD might include any of the
following: (1) says 'Huh' or 'What' often, (2) gives inconsistent responses
to auditory stimuli, (3) often misunderstands what is said, (4) is easily
distracted, (5) has reading, spelling and other academic problems, (6) has
poor attention, (7) has difficulty following oral instructions, (8) has
difficulty listening in the presence of background noise, (9) has poor receptive
and expressive language, (10) gives slow or delayed responses to verbal
stimuli and (11) exhibits behavior problems.
III. Diagnostic
Procedures
The first step in evaluating a child for CAPD is to rule out peripheral
hearing problems using pure tone thresholds, speech audiometry and middle-ear
testing. Furthermore, behavioral tests which degrade the speech signal using
various means, help to identify problems in the central auditory pathway
by reducing the normal level of redundancy present in that signal. Various
methods have been used to degrade the signal using low-pass filtering, altering
temporal aspects through interruption of compression, introducing a competing
signal in the same or opposite ear and through binaural stimulation requiring
integration of stimuli from both ears. It is generally accepted that no
one test is sufficiently sensitive to evaluate all CAPD problems. Therefore,
a battery of tests is usually the method of choice.
IV. Rehabilitation
Options
Once a child has been identified with CAPD most people would ask,
"Where do we go from here?". Since most children identified with
CAPD are school age, the most appropriate avenue for remediation would be
classroom management strategies utilized by the classroom teachers and dissemination
of information to other educators and adults who may come in contact with
the child. Furthermore, the special services department of the school may
have speech language pathologist(s) and or staff audiologist(s) who may
be able to help design an appropriate remediation therapy program. CAPD
is a relatively new area of public interest and numerous references on this
topic are available.