APD testing, that is, the assessment of (central) auditory processing disorders, (C)APDS, is an aspect of audiology with which many clinicians seem to struggle especially when working with children. Surveys indicate that audiologists’ knowledge and skills in this area could use scientific and ‘application focused‘ improvements. Additionally, it is difficult for audiologists to start this testing in their clinics, because no single test battery has been identified as being the gold standard.
Once an audiologist begins doing (C)AP evaluations, the intake of a thorough case history is recommended. The paper recommends that the following categories should be included when obtaining the history on an individual:
- family/genetic history
- pre-, peri-, and post-natal course
- health status
- listening and auditory behavior
- psychological factors
- educational achievement
- social development
- cultural and linguistic background
- prior related therapy
- current therapy
Clinically speaking, there will be times when parents do not report or know every aspect to their child’s health and development. A primary goal of the audiologist should be to clearly determine the parents’ reason for having their child tested (and that hearing concerns are a primary complaint).
A full peripheral hearing evaluation is the next step in obtaining necessary information from an individual. At the minimum, this should include hearing thresholds, tympanograms, acoustic reflexes, and acoustic emissions (OAEs). The auditory periphery’s state of health must be fully examined prior to the central auditory processing evaluation to rule out possible conductive or sensorineural hearing loss.
(C)AP 13 Test Principles
- audiologists should have the knowledge, training, and skills necessary to perform the testing
- the test battery should be driven by referring complaint
- audiologists should use “good tests” (i.e., established validity, reliability, and efficiency)
- audiologists should use tests that tax different auditory processes
- audiologists should use tests with verbal and nonverbal stimuli
- testing should be sensitive to attributes of the individual
- normative data should be available
- the audiologist should be aware of influences of age, especially on electro-physiologic tests
- test methods should be like those in the manual/literature
- the patient should be monitored and an appropriate duration of test session should be selected
- other professionals should collaborate with the audiologist
- if another deficit is suspected, the audiologist should refer on
- the (C)AP evaluation should be one part of a multifaceted evaluation and the audiologist should relate the findings to the referring complaint
Clinical Test Tips
It is important for audiologists to listen to the parents to better understand the referring complaint. In doing so, it would seem to establish a trusting, professional relationship. In addition, setting children at ease and encouraging them has seemed to also build trust. Giving children breaks during the approximate hour and a half test session is worthwhile (and implied in the paper). Watching body language, instead of a clock, is a good method to determine when refreshment is needed (e.g., if a child begins moving around in their seat frequently, and looking around the booth, it’s probably time for a break).
An important testing tip for audiologists is to be ready to move as fast as the child during the “easy tests” (e.g., ones to which the child responds quickly and correctly). As with other types of audiological procedures, audiologists should be prepared to make decisions quickly and to make the time to be accurate in their scoring and interpreting the results.
Time and Cost Factors
It is also important that clinics realize the large amount of time that the audiologist will need for testing, counselling, report writing, and communicating with other professionals. It would not seem unreasonable for an appointment and the report writing time to exceed four hours. Audiologists should be well aware that (C)AP evaluations are not quick and easy “squeeze-in” procedures. In addition, reimbursement from insurance is variable and might not cover the cost of the testing.
The audiologist performing CAP evaluations will see children with many different presenting problems and histories. It is important that the audiologist is aware of limitations (e.g., a child with a unilateral hearing loss), as well as possible obstacles (e.g., attention and fatigue), prior to performing the test battery in order to obtain accurate results. Interpretation of results should be guided by references listed in the Technical Report, as well as those found in this paper. In addition, the audiologist should contact other audiologists if they have questions about doing the testing or test results on a certain child, as well as contact those members of a child’s multidisciplinary team. Lastly, although not a part of this paper, the Technical Report lists many specific interventions for CAPD. Every audiologist should determine whether or not (C)AP testing is something that can be realistically implemented and maintained at their work setting.