Extended high frequency audiometry is particularly valuable in a number of clinical areas, such as ototoxicity monitoring, and may relate to speech recognition and localisation. Accurate and reliable extended high frequency testing, with smartphone technologies, has the potential to provide more affordable and widely available access in underserved contexts. The aim of the current study was to determine the accuracy and test-retest reliability of extended high frequency audiometry with a smartphone application, using calibrated headphones. Air conduction thresholds (8 – 16 kHz) and test-retest reproducibility recorded with conventional and smartphone audiometry, using standard audiometric (Sennheiser HDA 300) and non-standard audiometric headphones (Sennheiser HD202 II), was compared in a repeated-measures design. A total of 61 participants (122 ears) were included in the final analysis. Of these, 24 were adults with known exposure to ototoxic medications (mean age 36.8, SD 14.2 years; age range 22 – 64 years; 48% female), and 37 were adolescents (mean age 17.6, SD 3.2 years; age range 16 – 23 years; 76% female). Threshold comparisons were made between conventional audiometry and smartphone-based audiometry, with standard audiometric headphones and non-standard audiometric headphones. A paired samples t-test was used for comparison of threshold correspondence between conventional and smartphone thresholds, and test-retest reproducibility of smartphone thresholds. Conventional and smartphone thresholds corresponded at the lowest intensity (10 dB HL), using standard audiometric and non-standard audiometric headphones in 59.4% and 57.6% of cases, respectively. Conventional thresholds (exceeding 10 dB HL) corresponded within 10 dB or less, with smartphone thresholds in 82.9% of cases using standard audiometric headphones, and 84.1% of cases using non-standard audiometric headphones. There was no significant difference between conventional and smartphone audiometry using standard audiometric headphones across all frequencies (p>0.05). Test-retest comparison also showed no significant differences between conditions (p>0.05). Smartphone test-retest thresholds corresponded within 10 dB or less in 86.7% and 93.4% of cases using standard and nonstandard audiometric headphones, respectively. Extended high-frequency smartphone audiometry, with calibrated headphones, can provide an accurate and reliable option for affordable mobile audiometry. This type of technology may especially benefit those individuals receiving ototoxic medication in areas where diagnostic equipment, such as an audiometer with extended high frequency testing capabilities in a sound booth, are inaccessible.
Dissertation (MCommunication Pathology)--University of Pretoria, 2018.