What is the SCAN-3? The tests for auditory processing disorders explained

The SCAN-3 is a battery of recorded listening tests, published by Pearson and written by Robert W. Keith, PhD, that audiologists and speech-language pathologists use to help identify "auditory processing disorder," a difficulty in how the brain handles sound even though the ears hear normally. It comes in two forms: SCAN-3:C for children ages 5 through 12 and SCAN-3:A for adolescents and adults ages 13 through 50. The examiner plays words and sentences through headphones under difficult conditions, such as background babble, filtered speech, or a different word in each ear, and scores what the person repeats back. The SCAN-3 is not an IQ test. It measures a narrow set of listening skills, while an intelligence test estimates general reasoning ability, and clinicians often use the two side by side to work out whether a listening problem is auditory, cognitive, or both. This article covers the nine tests, the scores, the norms and reliability data, and why the diagnosis the battery supports is debated within audiology.

According to Pearson, the SCAN-3 is designed to "screen and diagnose auditory processing difficulties with one co-normed battery of tests." The publisher's technical report describes an individually administered battery that samples four areas: "temporal processing," meaning the timing side of hearing, such as detecting a brief silent gap between two tones; listening in noise; "dichotic listening," meaning handling different signals arriving at the two ears at once; and listening to degraded speech.

Those areas follow the definition used by the American Speech-Language-Hearing Association. ASHA uses the term "central auditory processing disorder," or CAPD, for deficits in the neural processing of auditory information that are not caused by higher-order language or cognitive factors, and states that CAPD is not caused by peripheral hearing loss, so a standard hearing test comes first. ASHA adds that CAPD may co-occur with ADHD, language disorder, or learning disability, which is where differential diagnosis becomes hard. Pearson's product page says the SCAN-3 helps "differentiate an auditory processing disorder from auditory attention problems and auditory comprehension difficulties," and its FAQ cautions that dichotic performance is not expected to exceed a person's general cognitive and language ability.

Pearson published both forms in 2009 as revisions of the earlier SCAN-C and SCAN-A.

• SCAN-3:C (Children): normed for ages 5 years 0 months through 12 years 11 months, with three screening tests, four diagnostic tests, and three supplementary tests.

• SCAN-3:A (Adolescents and Adults): normed for ages 13 years 0 months through 50 years 11 months, using the same nine tests. The brochure describes "continuous norming from ages 5:0 through 50:11."

• Administration time: Pearson lists 10 to 15 minutes for the screening tests and 30 to 45 minutes for the diagnostic tests. Directions and stimuli play from an audio CD, responses go on a paper record form, and scoring is by hand.

• Who can give it: Pearson assigns the SCAN-3 to qualification level B, which typically means a master's-level clinician such as an audiologist or speech-language pathologist trained in standardized assessment. The publisher's FAQ frames the audiologist as the professional who moves from screening to the diagnostic portion.

Pearson's brochure lists nine co-normed tests, and the technical report explains what each asks the examinee to do.

• Gap Detection: pairs of tones are played with silent gaps of varying length between them, and the listener says whether one tone or two was heard. Failing this screener flags a possible timing problem.

• Auditory Figure-Ground (+8 dB, +12 dB, and 0 dB): the listener repeats single words played over multi-talker babble. At +8 dB the words are 8 decibels louder than the babble, +12 dB is easier, and at 0 dB words and babble are equally loud. On the child form +8 dB is the screening and diagnostic level; on the adult form 0 dB is the screener.

• Competing Words, Free Recall: a different one-syllable word is played to each ear at the same time and the listener repeats both in any order. This is a screening test.

• Competing Words, Directed Ear: the same format, but the listener must repeat the words in a prescribed ear order, and only responses in that order count. This is a diagnostic test.

• Filtered Words: one-syllable words are low-pass filtered at 750 Hz so they sound muffled, similar to a poor phone line, and the listener repeats what was heard.

• Competing Sentences: unrelated sentences play simultaneously to the right and left ears, and the listener repeats the sentence from the ear the examiner names.

• Time Compressed Sentences: sentences are sped up by 60 percent, and the listener repeats them.

The screening tests yield "criterion-referenced" scores, a pass or fail against a cut point that the publisher's FAQ says decides whether the full battery should follow. The diagnostic and supplementary tests yield "scaled scores," which the technical report says run from 1 to 19, along with percentile ranks and descriptive classifications. The four diagnostic tests combine into an Auditory Processing Composite standard score with a range of 40 to 160, the same span used by most IQ-style standard scores.

Every test except Gap Detection also reports an "ear advantage" score, the right-ear raw score minus the left-ear raw score; the publisher treats an exaggerated right-ear or any left-ear advantage as relevant to the diagnostic picture.

Pearson's FAQ gives the manual's interpretive rule: a scaled score of 4 or lower on a single test, which is two standard deviations below the mean, or scores of 7 or lower on two or more tests, indicates a high probability of an auditory processing disorder. ASHA's practice portal describes a similar convention and adds that pervasive deficits across every test may signal a cognitive deficit or other nonauditory factor rather than an auditory one.

The technical report describes a standardization sample of 525 children ages 5 through 12, tested in 2007 and 2008 by 105 clinicians across 32 states and stratified by race and ethnicity, region, and caregiver education to match 2004 U.S. Census figures. The brochure reports 250 adolescents and adults in the SCAN-3:A sample, for 775 examinees in total.

On reliability, the report gives an average internal consistency of .91 for the child composite and .72 to .91 for the individual tests, with interscorer agreement of .98 to .99. Test-retest stability is lower: .54 to .73 for the individual tests and .77 for the composite. Those figures mean the individual SCAN-3 scores carry noticeable measurement error and the composite is the more dependable number. The brochure lists composite reliability of .93 for the adolescent and adult form.

Validity evidence includes a study of 40 children previously diagnosed with auditory processing disorder, each matched to a control from the norm sample, with what the report describes as moderate to large group differences, and a parallel study of 61 adolescents and adults. The report is candid about diagnostic accuracy: at a cut score below 8, the combined screening and diagnostic tests correctly identified 90 percent of previously diagnosed children but only 20 percent of those without the condition. A lenient cut catches most true cases and also flags many people who do not have the disorder, which is why a screening result is meant to trigger further evaluation rather than settle the question.

The category the SCAN-3 is built to detect is contested, and the field's own professional body says so. ASHA's practice portal states that professionals hold varying perspectives on CAPD that "reflect ongoing debate regarding how to define, assess, and treat" it, citing the heterogeneity of symptoms, variation in definitions, and the lack of a reference standard for diagnosis. ASHA reports that true prevalence is difficult to calculate for the same reasons, with published estimates in school-age children ranging from 0.2 percent to 6.2 percent.

Two peer-reviewed findings illustrate the disagreement. In a study of 1,469 randomly chosen British schoolchildren published in Pediatrics, David Moore and colleagues found that the presenting symptoms of auditory processing disorder were largely unrelated to auditory sensory processing, and that response variability, which reflects attention, and cognitive scores were the best predictors of poor listening; they suggested the condition is primarily an attention problem. A 2016 systematic review by Ellen de Wit and colleagues evaluated 48 studies, rated only one as methodologically strong, and concluded that the listening difficulties of children with the diagnosis may be a consequence of cognitive, language, and attention issues rather than bottom-up auditory processing. ASHA also cites a file review in which the share of referred children who qualified for the diagnosis ranged from 7.3 percent to 96 percent depending on which criteria were applied.

The SCAN-3 tasks remain standardized measures of real listening behaviors with published norms. A low score, though, describes performance on a specific task under specific acoustic conditions, and turning it into a diagnosis requires a qualified clinician weighing hearing status, attention, language, and cognition together. Pearson's FAQ adds that people for whom English is a second language typically score lower on all auditory processing tests.

Because listening difficulties overlap with attention and language problems, a comprehensive evaluation often includes a language test such as the CELF-5, a review of attention symptoms of the kind discussed in our article on IQ and ADHD, and an individually administered intelligence test such as the WISC. The IQ test sets the cognitive baseline. If reasoning and working memory are in the average range and the SCAN-3 composite is far below, the auditory explanation gains weight; if everything is uniformly low, ASHA's guidance points toward a broader cognitive or language explanation.

For adults who want a sound estimate of that baseline, the RIOT IQ test, the Reasoning and Intelligence Online Test developed by RIOT IQ with psychometrician Dr. Russell T. Warne, is an online option for people 18 and older. It takes about 52 minutes, contains 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), and reports scores on the mean-100, standard-deviation-15 scale. It does not assess auditory processing, does not detect any disorder, and does not replace an individually administered diagnostic evaluation. What it offers is a reliable picture of general reasoning ability, the reference point a clinician needs before deciding what a listening score means. You can learn more at RIOT IQ.

No. The SCAN-3 measures specific listening skills under degraded or competing acoustic conditions. An IQ test measures general reasoning ability across verbal, quantitative, spatial, and memory tasks. Clinicians often use both so they can compare listening performance against overall cognitive ability.

Pearson lists the SCAN-3 at qualification level B. Its technical report names audiologists, speech-language pathologists, and other professionals trained in standardized assessment, and the FAQ describes the audiologist as the clinician who carries out the diagnostic portion.

Pearson lists 10 to 15 minutes for the screening tests and 30 to 45 minutes for the diagnostic tests. Supplementary tests add time if the clinician gives them.

SCAN-3:C covers ages 5 years 0 months through 12 years 11 months. SCAN-3:A covers ages 13 years 0 months through 50 years 11 months. The publisher describes the norms as continuous across the full span.

Pearson's materials say the diagnostic tests provide information that, combined with observations and other data, enables a clinician to make a diagnostic decision. ASHA notes that the field has no reference standard for the diagnosis, so a single score is a starting point for clinical judgment rather than a verdict.

No. The SCAN-3 does not measure intelligence. A low listening score in a child with average reasoning scores points toward a listening-specific issue; uniformly low scores across all tests call for a broader evaluation by a qualified clinician.

1. Pearson. (n.d.). SCAN-3:C Tests for Auditory Processing Disorders for Children. pearsonassessments.com

2. Pearson. (n.d.). SCAN-3:A Tests for Auditory Processing Disorders in Adolescents and Adults. pearsonassessments.com

3. Keith, R. W. (2012). SCAN-3 for Children: Tests for Auditory Processing Disorders technical report. Pearson. pearsonassessments.com

4. Pearson. (2009). SCAN-3: It takes more than listening to connect [Brochure]. pearsonassessments.com

5. American Speech-Language-Hearing Association. (n.d.). Central auditory processing disorder [Practice portal]. asha.org

6. Moore, D. R., Ferguson, M. A., Edmondson-Jones, A. M., Ratib, S., & Riley, A. (2010). Nature of auditory processing disorder in children. Pediatrics, 126(2), e382-e390. pubmed.ncbi.nlm.nih.gov

7. de Wit, E., Visser-Bochane, M. I., Steenbergen, B., van Dijk, P., van der Schans, C. P., & Luinge, M. R. (2016). Characteristics of auditory processing disorders: A systematic review. Journal of Speech, Language, and Hearing Research, 59(2), 384-413. pubmed.ncbi.nlm.nih.gov

Hero photo: A person wearing headphones during a hearing test. U.S. Marine Corps photo, public domain, via Wikimedia Commons (cropped).