Validity of automated threshold audiometry : a systematic review and meta-analysis

23 Jun 2014

OBJECTIVES : A systematic literature review and meta-analysis on the validity (test–retest reliability and accuracy) of automated threshold audiometry compared with the gold standard of manual threshold audiometry was conducted. DESIGN : A systematic literature review was completed in peer-reviewed databases on automated compared with manual threshold audiometry. Subsequently a meta-analysis was conducted on the validity of automated audiometry. METHODS : A multifaceted approach, covering several databases and using different search strategies was used to ensure comprehensive coverage and to cross-check search findings. Databases included: MEDLINE, Scopus, and PubMed; a secondary search strategy was the review of references from identified reports. Reports including within-subject comparisons of manual and automated threshold audiometry were selected according to inclusion/exclusion criteria before data were extracted. For the meta-analysis weighted mean differences (and standard deviations) on test–retest reliability for automated compared with manual audiometry were determined to assess the validity of automated threshold audiometry. RESULTS : In total, 29 reports on automated audiometry (method of limits and the method of adjustment techniques) met the inclusion criteria and were included in this review. Most reports included data on adult populations using air conduction testing with limited data on children, bone conduction testing and the effects of hearing status on automated audiometry. Metaanalysis test–retest reliability for automated audiometry was within typical test–retest variability for manual audiometry. Accuracy results on the meta-analysis indicated overall average differences between manual and automated air conduction audiometry (0.4 dB, 6.1 SD) to be comparable with test–retest differences for manual (1.3 dB, 6.1 SD) and automated (0.3 dB, 6.9 SD) audiometry. No significant differences (p > 0.01; summarized data analysis of variance) were seen in any of the comparisons between test–retest reliability of manual and automated audiometry compared with differences between manual and automated audiometry. CONCLUSION : Automated audiometry provides an accurate measure of hearing threshold, but validation data are still limited for (1) automated bone conduction audiometry; (2) automated audiometry in children and difficult-to-test populations and; (3) different types and degrees of hearing loss.