The original SCAN test published in the early 1980s was designed to be a screening test. It soon became clear that the test provided important diagnostic information and with the subsequent revision it was published as a test of auditory processing disorders, i.e. a diagnostic test.
Standardized scores used in medicine, psychology, education, and speech-language pathology are used for diagnostic purposes. The ability to determine a subject’s performance at a specific level and categorize that performance as normal or not is very specifically what is used in fields such as medicine, where performance below -2 SD is considered pathological.
The current SCAN-3 batteries contain the major tests recommended by position papers published by ASHA and AAA. There are small portions of the most recent versions that may be used as screening tools. Primarily, however, they are diagnostic in nature. While some might argue that test of auditory processing disorders (APD) are not or should not be diagnostic in nature, the SCAN tests are designed to be so. Conversely, if the SCAN test batteries are not diagnostic, then what tests are available that have better normative data? Professionals familiar with the APD literature and available tests of auditory processing recognize that published norms are not available for a majority of tests currently used. When cut-scores are recommended in the literature there often is little, if any information available to the user on how those scores were obtained.
The most recent revision of the test batteries, SCAN:3 for Children, Tests of Auditory Processing Disorders and SCAN:3 for Adolescents and Adults, include:
- Three screening measures with criterion referenced cut-off scores;
- Four tests of auditory processing used to develop the composite score; and
- Three optional tests of auditory processing including two additional signal-to-noise ratios and a time compressed sentence test.
In addition, the manual describes administering the Competing Words test under free recall and then directed ear conditions in order to assess higher order memory/executive functions. The revised test batteries were completely renormed on 775 subjects.
It may be of interest to the readers of this note that Friburg & McNamara (2010) found that SCAN-C and SCAN-A have the highest level of sensitivity and specificity of any auditory processing test or battery.
By Robert W. Keith, Ph.D.
University of Cincinnati – College of Allied Health Sciences
Department of Communications Sciences and Disorders
Department of Otolaryngology
University of Cincinnati College of Medicine
Friberg, J.C. & McNamara, T.L. (2010). Evaluating the reliability and validity of (Central) Auditory Processing Tests: A preliminary investigation. Journal of Educational Audiology, 2.