The virtual audiometer (VA) is a software application that simulates a pure tone audiometer by delivering tones of different frequencies and intensities by air conduction.
Objectives: To determine correlation between hearing thresholds measured by virtual and pure tone audiometry and degree of agreement in their hearing loss classification.
Methods: Analytic, cross-sectional study set in a Philippine tertiary institution. Subjects were recruited from the outpatient department in September 2005 and comprised of cooperative, clinically normal and abnormal hearing individuals. Thirty-two subjects made 64 total ears tested (n=64), giving 0.90 correlation at 0.05 level of significance (?) (p = 0.05) and 99% power. Each subject underwent pure tone and virtual audiometry, the average thresholds calculated, and degree of hearing loss categorized according to classification by the World Health Organization (WHO). Results were not revealed until both examinations were completed. Data were stratified by frequency and compared by Pearson's correlation, while Kappa statistics determined degree of agreement between
WHO grades of hearing impairment.
Results: Average age was 40.2 years, with 20-80 year range and 18.5 years standard deviation. Nine subjects were male while 23 were female (M:F ratio = 0.39). Of 64 ears, 34 were clinically normal and 30 were abnormal. Pearson's correlation demonstrated significant positive correlation between virtual and pure tone thresholds with 99% confidence at 0.05 level of significance. Kappa statistics also showed significant degrees of agreement in WHO grades by both instruments, meaning VA will probably categorize hearing loss in the same manner as pure tone audiometry.
Conclusion: A strong positive correlation exists between hearing thresholds measured by virtual and pure tone audiometry with a significant degree of agreement in hearing loss classification. This supports the possibility of using the virtual audiometer as a clinic-based, air-conduction audiometer for screening and monitoring. When used in conjunction with other examinations, valuable information on over-all integrity of the audiologic system may be ascertained.