Results from a National Central Auditory Processing Disorder Service: A Real-World Assessment of Diagnostic Practices and Remediation for Central Auditory Processing Disorder

Abstract

This article describes the development and evaluation of a national service to diagnose and remediate central auditory processing disorder (CAPD). Data were gathered from 38 participating Australian Hearing centers over an 18-month period from 666 individuals age 6, 0 (years, months) to 24, 8 (median 9, 0). A total of 408 clients were diagnosed with either a spatial processing disorder (n = 130), a verbal memory deficit (n = 174), or a binaural integration deficit (n = 104). A hierarchical test protocol was used so not all children were assessed on all tests in the battery. One hundred fifty clients decided to proceed with deficit-specific training (LiSN & Learn or Memory Booster) and/or be fitted with a frequency modulation system. Families were provided with communication strategies targeted to a child's specific listening difficulties and goals. Outcomes were measured using repeat assessment of the relevant diagnostic test, as well as the Client Oriented Scale of Improvement measure and Listening Inventories for Education teacher questionnaire. Group analyses revealed significant improvements postremediation for all training/management options. Individual posttraining performance and results of outcome measures also are discussed.

Keywords: Central auditory processing disorder; deficit-specific auditory training; spatial processing disorder.

Figure 1

Flowchart of the test appointment procedure used. Abbreviations: CAPD, central auditory processing disorder; CHL, conductive hearing loss; HC, high cue; LiSN-S, Listening in Spatialized Noise–Sentences Test; SNHL, sensorineural hearing loss.

Figure 2

Summary of diagnostic results (n = 666). Abbreviations: DDT, Dichotic Digits Test; LiSN-S HC, high-cue; LiSN-S, Listening in Spatialized Noise–Sentences Test; SPD, spatial processing disorder.

Figure 3

Pie chart displaying reasons provided for incomplete LiSN & Learn training (n = 28).

Figure 4

Mean performance on the LiSN-S pre- (dashed line) versus post- (solid line) LiSN & Learn training (n = 40 high cue; n = 34 other conditions) *conditions with significant differences over time are preceded by an asterisk. Performance is expressed in population standard deviation units from the mean. Error bars represent 95% confidence intervals. Abbreviations: adv, advantage; LiSN-S, Listening in Spatialized Noise–Sentences Test.

Figure 5

Scatterplot of Listening in Spatialized Noise–Sentences Test (LiSN-S) pattern score pre- versus post-LiSN & Learn training (n = 34). Solid line represents least squares regression line. The dashed line indicates no change in performance after training.

Figure 6

Histogram of Client Oriented Scale of Improvement–Children (COSI-C) ratings for participants who completed the LiSN & Learn (n = 33).

Figure 7

Pie chart displaying reasons for incomplete Memory Booster training (n = 21).

Figure 8

Dot plot of mean results on the (A) number memory forward (NMF) and (B) number memory reversed (NMR) Test of Auditory Processing–Third Edition subtests (n = 18 and 17, respectively) pre- and posttraining with Memory Booster. Error bars represent the 95% confidence intervals.

Figure 9

Scatterplot of individual results on the (A) number memory forward (NMF) and (B) number memory reversed (NMR) Test of Auditory Processing–Third Edition subtests (n = 18 and 17 respectively) pre- and posttraining with Memory Booster. Large dots represent data points for three participants, medium dots represent two participants. Solid line represents least squares regression line. The dashed line indicates no change in performance after training. The shaded area represents performance within normal limits.

Figure 10

Histogram of Client Oriented Scale of Improvement–Children (COSI-C) ratings for participants who completed Memory Booster training (n = 25).

Figure 11

Histogram of Client Oriented Scale of Improvement–Children COSI-C scores for participants fitted with a frequency modulation system (FM) only (n = 16).

Figure A1

Relationship between scores on the Listening in Spatialized Noise–Sentences Test high-cue test and (A) the spatial advantage, (B) pattern measure, and (C) low-cue measures. Abbreviation: SRT, Speech Reception Threshold.