Audiometric Characteristics of Hyperacusis Patients

Abstract

Hyperacusis is a frequent auditory disorder where sounds of normal volume are perceived as too loud or even painfully loud. There is a high degree of co-morbidity between hyperacusis and tinnitus, most hyperacusis patients also have tinnitus, but only about 30–40% of tinnitus patients also show symptoms of hyperacusis. In order to elucidate the mechanisms of hyperacusis, detailed measurements of loudness discomfort levels (LDLs) across the hearing range would be desirable. However, previous studies have only reported LDLs for a restricted frequency range, e.g., from 0.5 to 4 kHz or from 1 to 8 kHz. We have measured audiograms and LDLs in 381 patients with a primary complaint of hyperacusis for the full standard audiometric frequency range from 0.125 to 8 kHz. On average, patients had mild high-frequency hearing loss, but more than a third of the tested ears had normal hearing thresholds (HTs), i.e., ≤20 dB HL. LDLs were found to be significantly decreased compared to a normal-hearing reference group, with average values around 85 dB HL across the frequency range. However, receiver operating characteristic analysis showed that LDL measurements are neither sensitive nor specific enough to serve as a single test for hyperacusis. There was a moderate positive correlation between HTs and LDLs (r = 0.36), i.e., LDLs tended to be higher at frequencies where hearing loss was present, suggesting that hyperacusis is unlikely to be caused by HT increase, in contrast to tinnitus for which hearing loss is a main trigger. Moreover, our finding that LDLs are decreased across the full range of audiometric frequencies, regardless of the pattern or degree of hearing loss, indicates that hyperacusis might be due to a generalized increase in auditory gain. Tinnitus on the other hand is thought to be caused by neuroplastic changes in a restricted frequency range, suggesting that tinnitus and hyperacusis might not share a common mechanism.

Salicylate-induced hyperacusis in rats: Dose- and frequency-dependent effects

“…Human perceptual data suggest that hyperacusis patients with either little or moderate hearing loss (Noreña and Chery-Croze, 2007; Sheldrake et al, 2015), and normal-hearing listeners following a 2-week ear-plugging treatment (Formby et al, 2003), tend to experience reduced loudness discomfort levels across a broad range of stimulus frequencies suggesting that, together with previous animal physiological data, hyperacusis may be the result of an aberrant central gain mechanism (Salvi et al, 2000; Chen et al, 2013; Zeng, 2013; Auerbach et al, 2014; Hickox and Liberman, 2014). Since high-dose salicylate in the current study significantly reduced RTs at high sound levels across all stimulus frequencies tested and salicylate-induced tinnitus in rats appears to be atonal (Turner and Parrish, 2008; Jones and May 2017), the results from our frequency-response experiment, along with animal tinnitus experiments, provide additional evidence of a central neural excitability mechanism as an explanation of salicylate-induced changes in loudness perception.…”

Health‐relevant personality is associated with sensitivity to sound (hyperacusis)

“…One of the strengths of this study is the combination of both clinical and subjective measures of hyperacusis. Most previous studies rely on either subjective or clinical, for instance (Andersson et al ., ; Sheldrake et al ., ) and may therefore capture different aspects of a phenomenon. The results from the present study indicate that different measures of hyperacusis may be useful in order to capture a multifaceted picture of this phenomenon, that is, the clinical and the psychological.…”

Minimally Invasive Surgery for the Treatment of Hyperacusis

“…The accepted normal reference level for the ULL is considered 100 dB HL for the frequencies from 500 to 8000 Hz and for speech according to American Academy of Audiology (31). However, caution must be exercised when interpreting ULL measures as they may lack the specificity and sensitivity necessary to confirm a diagnosis of hyperacusis (7). Test-retest reliability has also been questioned.…”

“…The majority of existing studies describe the occurrence of hyperacusis in patients with tinnitus. The incidence of hyperacusis in individuals with tinnitus has been reported as high as 40 to 86% (6,7). …”