On the diagnosis of auditory processing disorder (APD).

I f you spend much time around audiologists interested in auditory processing disorder (APD), sooner or later you will hear the statement that a test for APD must be ''simple, quick, cheap, and easily scored.'' Otherwise, it is solemnly averred, ''clinicians will not use it.'' This mantra has achieved virtually biblical status. The assumption seems to be that one can make the diagnosis of APD in a child given the availability of a few simple tests but that, if such instruments are not at the busy clinician's fingertips, this troubling malady will remain forever undiscovered in countless children. The consequence of such a mindset is that we have a number of ''simple, quick, cheap, and easily scored'' tests for APD that often identify symptoms of APD in significant percentages of otherwise normal, complaint-free children whohavebeenrecruitedfor controlgroups.Ithasinaddition fostered, especially on the Internet, the worldwide circulation of an unbelievable amount of nonsense about APD— what it is and what it is not. A possible basis for this unfortunate situation is that tests meeting these permissive inclusion criteria are very likely to be plagued by the influence of nonauditory factors. Current APD tests tend to be fashioned after one or more psychoacoustic models, that is, the tester presents an auditory task and scores how well the child performs the task along some measurement dimension (e.g., percent-correct repetition, gap-detection threshold, interaural difference, etc.). The performance measure is assumed to reflect nothing but auditory perceptual ability. It is then a simple matter to assess abnormality by comparing the child's performance to the distribution of such performance in a normative group. But psychoa-cousticians learned many years ago that relatively uncontaminated behavioral measures of perceptual abilities are not easily obtained, even in cooperative young adults, by procedures that are ''simple, quick, cheap, and easily scored.'' A serious psychoacoustic investigator might, for example, test an adult participant for two to three days, using time-consuming and complex procedures involving expensive equipment, and then routinely discard, as unusable, all of the data gathered on the first day of testing. Some audiologists, on the other hand, want to test a child for only 15–30 minutes and expect to get the same quality of information. It may be that this is exactly the wrong way to approach the problem of diagnosing an auditory perceptual deficit in a child. Over the past few decades dramatic advances in understanding how the brain works and …