PP1316 - Effects of Virtual-Reality Music Exposure and Mental Stress on Words-in-Noise Performance

The standard audiogram has received criticism for lacking the sensitivity to detect early indications of threshold and suprathreshold changes. Studies suggest that noise-induced hearing loss may be more discernable in suprathreshold, hearing-in-noise measures. Furthermore, animal studies suggest that one contributing factor of threshold shift susceptibility may be mental stress, which can cause vasoconstriction of blood vessels. As such, the purpose of this study was twofold: 1) investigate the sensitivity of the Words-In-Noise test to detect slight, suprathreshold noise-induced changes in the absence of temporary threshold shift, and 2) evaluate the relationship between participant’s stress level and their Words-in-Noise performance.

Summary:

Purpose: We tested the hypotheses that 1) evidence of slight, temporary auditory changes following a noise exposure will appear in Words-in-Noise test performance in the absence of standard, audiometric threshold shift, and 2) evidence of high mental stress levels would be correlated with increased evaluate the relationship between participant’s stress level and their Words-in-Noise performance.

Methods: 31 young, adult participants (18-25 yrs.) (14 M; 17 F) were enrolled in the study, each meeting study criteria of normal hearing sensitivity (<16 dB HL .25- 8 kHz; 2-dB HL audiometry steps), two healthy pinnae and ear canals (< 10% cerumen occlusion), and Type A tympanograms (226 Hz tone). Participants attended Session A, in which a Perceived Stress Scale (PSS) survey was completed, as well as distortion product otoacoustic emissions (DPOAE, 1-12 kHz), auditory brainstem response (click; 1 kHz, 2 kHz, 4 kHz tone), and Words-in-Noise testing baseline measures were established. Subsequently, participants watched a popular, 1 hour 29-minute virtual reality music concert (average level equivalent = 78.7 dB; 5.8% NIOSH noise dose), using the Oculus Go virtual reality headset. All auditory measurements were repeated immediately post-exposure, and again between one day and one week post-exposure.

Results: No statistically significant differences emerged between males and females in total Perceived Stress Scale (PSS) scores, nor between males and females in baseline or post-exposure WIN performance. In this study, temporary threshold shift ranged from none to slight across participants, and was not sufficient at producing clinically relevant, temporary changes in WIN performance (a suprathreshold measure). No correlation was observed between participants’ PSS scores and WIN performance at baseline or post-exposure.

Impact: For the past 15 years, researchers and clinicians have newly criticized our reliance on the standard audiogram to explain all auditory complaints. Of particular interest is a selective, permanent injury to the synapses that connect the inner hair to the auditory nerve; a lesion which may remain permanent despite a fully recovered (temporary) audiometric shift following a noise exposure. This selective lesion has been observed in animal models following moderate to severe amounts of temporary threshold shift induced by artificial, octave-band exposures, though there is not universal agreement that this type of selective loss would occur naturally in humans following a recreational noise exposure. We studied post-exposure performance on the WIN, which has been proposed as a functional deficit of synaptic loss, and mental stress - a variable that may increase susceptibility to noise injury.

Innovation: Few studies have prospectively analyzed slight, temporary threshold shift from common recreational music exposures (such as music concerts) for young adults, as the logistics of doing so are complex. We brought this music concert to the laboratory setting by experiencing it in a commercially available, virtual reality headset, which has become a common pastime for young adults. We further tested the influence of stress on temporary auditory changes, and diligently recruited a dataset of young adults who exhibited robust hearing sensitivity, without any potential age-related synaptopathic damage, nor any prior exposure to firearm discharge.