Background: Eclectic test combinations are usually applied for diagnosing (Central) Auditory Processing Disorders (C)APD in school-aged children.
Methods: Children with suspected APD were examined with a combination of 12 audiological and psychometric tests in order to allow the proper allocation to either the APD-group or to the Non-APD-group.
Patients: Forty-six 8-10-year-old children diagnosed with auditory-specific perceptual deficits [clinical group (C)APD; average age 9;2 years; SD 0;7 years] were compared to 39 normally developed children of the same age span with no evidence of specific language impairment, developmental dyslexia or learning disorders [control group Non-APD; average age 9;3 years; SD 0;7 years].
Results: Overall, the Non-APD-group scored significantly better than the (C)APD-group with the exception of three non-verbal auditory tests. The clinical group and the control group were successfully differentiated: 94% and (after cross-validation) 91% of the children respectively could be diagnosed correctly by using only three tests (significant discriminant function). Of these, Mottier's Test (nonword repetition) showed the highest discriminatory power followed by speech in noise discrimination and "phoneme differentiation" of the Heidelberger Phoneme Discrimination Test.
Conclusion: After the differential diagnostic exclusion of peripheral hearing disorders and cognitive impairments, these three tests are sufficient to initially justify the clinical-diagnostic classification "(C)APD" in 8-11-year-old children taking into account only a relatively slight probability of error. Poor results in two of the three differentiating tests (discrepancy criterion of >1 SD of the reference population) are sufficient to support the diagnostic classification of an (C)APD.