Adapting Audiology Procedures During the Pandemic: Validity and Efficacy of Testing Outside a Sound Booth

Purpose: This investigation aims to provide outcomes from a clinical perspective on the validity and efficacy of a wireless automated audiometer system that could be used in multiple settings when a sound booth is not accessible. Testing was conducted in a clinical setting under modified protocols meeting safety precautions during the COVID-19 pandemic. Method: Four doctoral students in audiology served as examiners. Participants were 69 adults between the ages of 20 and 69 years, with normal hearing (≤ 25 dB HL; n = 110 ears) or hearing loss (> 25 dB HL; n = 25 ears). Two versions of a pure-tone air-conduction threshold test following a modified Hughson-Westlake approach were performed and compared at 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz (a) in a sound-treated test booth using standard manual audiometry and (b) in a quiet, nonsound-treated clinical room (sound booth free) using automated KUDUwave audiometry. Participants were asked to complete a five-item feedback questionnaire, and examiners were interviewed to report on their experience. Results: Clinical validity to within ±10 dB of standard audiometry was demonstrated for 94.5% of the total thresholds ( n = 937) measured with the sound booth–free approach. Less accuracy (73.3%) was observed using a ±5 dB comparison. When comparing the mean thresholds, there were significant differences ( p < .01) between the mean thresholds at most frequencies, with mean sound booth thresholds being higher than the sound booth–free mean thresholds. A strong threshold correlation (.91–.98) was found between the methods across frequencies. Participant and examiner feedback supported the efficacy of the sound booth–free technology. Conclusions: Findings support sound booth–free, automated software-controlled audiometry with active noise monitoring as a valid and efficient procedure for pure-tone hearing threshold assessment. This method offers an effective alternative when circumstances require more transportable hearing assessment technology or do not allow for standard manual audiometry in a sound booth.

Threshold assessment, categorical perception, and the evolution of reliable signaling

Animals often use assessment signals to communicate information about their quality to a variety of receivers, including potential mates, competitors, and predators. But what maintains reliable signaling and prevents signalers from signaling a better quality than they actually have? Previous work has shown that reliable signaling can be maintained if signalers pay fitness costs for signaling at different intensities and these costs are greater for lower quality individuals than higher quality ones. Models supporting this idea typically assume that continuous variation in signal intensity is perceived as such by receivers. In many organisms, however, receivers have threshold responses to signals, in which they respond to a signal if it is above a threshold value and do not respond if the signal is below the threshold value. Here, we use both analytical and individual-based models to investigate how such threshold responses affect the reliability of assessment signals. We show that reliable signaling systems can break down when receivers have an invariant threshold response, but reliable signaling can be rescued if there is variation among receivers in the location of their threshold boundary. Our models provide an important step towards understanding signal evolution when receivers have threshold responses to continuous signal variation.