Department of Physiology, Anatomy and Genetics (DPAG), University of Oxford, OX1 3PT Oxford, UK.
J Integr Neurosci. 2024 Sep 29;23(10):183. doi: 10.31083/j.jin2310183.
In the auditory domain, temporal resolution is the ability to respond to rapid changes in the envelope of a sound over time. Silent gap-in-noise detection tests assess temporal resolution. Whether temporal resolution is impaired in tinnitus and whether those tests are useful for identifying the condition is still debated. We have revisited these questions by assessing the silent gap-in-noise detection performance of human participants.
Participants were seventy-one young adults with normal hearing, separated into preliminary, tinnitus and matched-control groups. A preliminary group (n = 18) was used to optimise the silent gap-in-noise detection two-alternative forced-choice paradigm by examining the effect of the position and the salience of the gap. Temporal resolution was tested in case-control observational study of tinnitus (n = 20) and matched-control (n = 33) groups using the previously optimized silent gap-in-noise behavioral paradigm. These two groups were also tested using silent gap prepulse inhibition of the auditory startle reflex (GPIAS) and Auditory Brain Responses (ABRs).
In the preliminary group, reducing the predictability and saliency of the silent gap increased detection thresholds and reduced gap detection sensitivity (slope of the psychometric function). In the case-control study, tinnitus participants had higher gap detection thresholds than controls for narrowband noise stimuli centred at 2 and 8 kHz, with no differences in GPIAS or ABRs. In addition, ABR data showed latency differences across the different tinnitus subgroups stratified by subject severity.
Operant silent gap-in-noise detection is impaired in tinnitus when the paradigm is optimized to reduce the predictability and saliency of the silent gap and to avoid the ceiling effect. Our behavioral paradigm can distinguish tinnitus and control groups suggesting that temporal resolution is impaired in tinnitus. However, in young adults with normal hearing, the paradigm is unable to objectively identify tinnitus at the individual level. The GPIAS paradigm was unable to differentiate the tinnitus and control groups, suggesting that operant, as opposed to reflexive, silent gap-in-noise detection is a more sensitive measure for objectively identifying tinnitus.
在听觉领域，时间分辨率是指随时间响应声音包络快速变化的能力。无声噪声检测测试评估时间分辨率。耳鸣患者的时间分辨率是否受损，以及这些测试是否有助于识别耳鸣，仍然存在争议。我们通过评估人类参与者的无声噪声检测性能来重新研究这些问题。
参与者为 71 名听力正常的年轻人，分为初步组、耳鸣组和匹配对照组。初步组（n=18）用于通过检查间隙位置和显著度对无声噪声检测二选一强制选择范式的影响来优化该范式。使用之前优化的无声噪声行为范式，在耳鸣病例对照观察研究（n=20）和匹配对照组（n=33）中测试时间分辨率。这两组还使用无声间隙预脉冲抑制听觉惊跳反射（GPIAS）和听觉脑反应（ABR）进行测试。
在初步组中，降低无声间隙的可预测性和显著度会增加检测阈值并降低间隙检测灵敏度（心理物理函数的斜率）。在病例对照研究中，与对照组相比，窄带噪声刺激中心位于 2 kHz 和 8 kHz 的耳鸣参与者的间隙检测阈值更高，而在 GPIAS 或 ABR 中没有差异。此外，ABR 数据显示，根据严重程度对不同耳鸣亚组分层后，潜伏期存在差异。
当优化范式以降低无声间隙的可预测性和显著度并避免上限效应时，操作式无声噪声检测在耳鸣中受损。我们的行为范式可以区分耳鸣组和对照组，表明耳鸣患者的时间分辨率受损。然而，在听力正常的年轻成年人中，该范式无法在个体水平上客观地识别耳鸣。GPIAS 范式无法区分耳鸣组和对照组，这表明操作性而非反射性无声噪声检测是客观识别耳鸣的更敏感指标。
