Random Gap Detection Test (RGDT) – Standard

The Random Gap Detection Test-Standard (RGDT) is an auditory processing disorder test for ages 5 and up using non-verbal stimuli. It is considered a temporal test using temporal resolution and is sensitive to cortical particularly left temporal lobe lesions.

This test is a variation on the AFT-R.  It differs from the AFT-R:  First, in the AFT-R, the stimulus presentations are in serial order from no gap to large gap and back to no gap, often resulting in perseveration in some subjects.  Since randomization successfully eliminates the problem of perseveration, the RGDT gap duration presentations of the stimuli are randomized.  Second, the number of test frequencies has been reduced to four.  Third, Click stimuli have been added. The developer states it takes approximately 10 minutes to administer and score the RGDT.

The Random Gap Detection Test-Standard (RGDT) includes a) audio recording, and b) manual and score forms as printable pdf files. The 31-page manual is comprised of sections on development, background, administration, and interpretation. It includes normative data for ages 5-7, 8, 9, and 10-11. The developer recommends using the normative data for the 10-11 age category as a guideline for testing patients older than 11. (Normative values for the AFT-R are included for ages 5-70 due to their similarity.) Available from Auditec, Inc.  Call 1-800-669-9065 (from US) or 314-416-1050 (outside the US) to order. FREE shipping to contiguous US locations.

Random Gap Detection Test; Item 207; Price $113.00 USD S&H
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*Administrators who are interested in measuring improvement in temporal processing abilities following remediation should purchase the RGDT-Standard & Expanded version instead.



Until the Auditory Fusion Test-Revised was released, one aspect of temporal (central) processing, gap detection (temporal resolution), had been generally ignored. The Auditory Fusion Test–Revised (AFT-R) was produced in response to the ASHA task force position statement on central auditory processing to fill this void. AFT-R is an easily administered and efficient test for identifying temporal processing deficits including problems with temporal resolution and gap detection. AFT-R has the distinct advantage of being a non-linguistic measure, making linguistic background irrelevant in interpretation of results. Normative data are included in the manual. Administration time is less than 20 minutes.

The Auditory Fusion Test-Revised includes a) audio recording, and b) instructions and score form as printable pdf files. Available from Auditec, Inc. Call 1-800-669-9065 (from US) or 314-416-1050 (outside the US) to order. FREE shipping to contiguous US locations.

Auditory Fusion Test-Revised (AFT-R); Item 203; Price $137.25 USD S&H
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The Random Gap Detection Test is considered a more recent version of this test. Although the more recent version is preferred by most professionals, the AFT-R still proves to be useful to some audiologists.