■这项研究旨在确定职业安全与健康管理局(OSHA)兼容噪声对听觉健康的影响,并评估噪声前近红外(NIR)光疗是否可以减轻噪声暴露的影响。
■在四次访问中,听力正常的参与者(n=30,NCT#:03834714)完成基线听力健康评估,然后暴露于开放耳朵,94dBA的连续粉红噪声持续15分钟。此后不久,在3000、4000和6000Hz的噪声后听力测试和失真产物耳声发射(DPOAEs)与改良韵律测试(MRT)一起进行,屏蔽级差测试(MLD),和固定电平频率测试(FLFT)[统称为中央和周围听觉测试电池(CPATB)]以获取基线噪声灵敏度曲线。然后,参与者被随机分配到主动或假NIR光治疗30分钟,以结束第1次访问。第2次访视(从第1次访视起≥24且≤48小时)开始,再进行30分钟的主动NIR光疗或假手术,然后重复CPATB测试和噪声暴露。在噪声暴露后立即再次进行噪声后测试以评估NIR光疗法的效果。其余的访问是在交叉设计的噪音休息≥2周后进行的(即,那些在第1次和第2次访问中接受过主动NIR光疗法的人在第3次和第4次访问中接受了假手术疗法)。
■在每次访视结束时完成恢复听力测试和DPOAE。参与者在噪声暴露后立即经历了临时阈值变化(TTS),平均位移为6.79dBHL(±6.25),10.61dBHL(±6.89),和7.30dBHL(±7.25)在3000,4000和6000Hz,分别,尽管所有阈值在噪声暴露后75分钟内恢复到3000、4000和6000Hz的基线。矛盾的是,在3000Hz时,主动NIR光治疗的阈值变化在统计学上高于假手术治疗(p=0.04)。但在其他测试频率没有观察到其他差异。年龄亚分析表明,与积极治疗相比,假手术治疗组的年轻成年人的TTS通常更大。虽然这在统计学上没有差异。活动组或假手术组的CPATB测试结果没有差异。最后,我们观察到噪声暴露后听觉功能或中央处理没有变化,暗示健康和有弹性的内耳。
■在这项研究中,在噪声暴露前局部施用NIR在减轻噪声诱发的TTS方面没有显著的保护作用.需要进一步探索以实施这种有前途的耳保护疗法的有效剂量和给药。
UNASSIGNED: This study sought to determine the effect of Occupational Safety and Health Administration (OSHA) compliant noise on auditory health and assess whether pre-noise near infrared (NIR) light therapy can mitigate the effects of noise exposure.
UNASSIGNED: Over four visits, participants (n = 30, NCT#: 03834714) with normal hearing completed baseline hearing health assessments followed by exposure to open ear, continuous pink noise at 94 dBA for 15 min. Immediately thereafter, post-noise hearing tests at 3000, 4000, and 6000 Hz and distortion product otoacoustic emissions (DPOAEs) were conducted along with the Modified Rhyme Test (MRT), Masking Level Difference Test (MLD), and Fixed Level Frequency Tests (FLFT) [collectively referred to as the Central and Peripheral Auditory Test Battery (CPATB)] to acquire baseline noise sensitivity profiles. Participants were then randomized to either Active or Sham NIR light therapy for 30 min binaurally to conclude Visit 1. Visit 2 (≥24 and ≤ 48 h from Visit 1) began with an additional 30-min session of Active NIR light therapy or Sham followed by repeat CPATB testing and noise exposure. Post-noise testing was again conducted immediately after noise exposure to assess the effect of NIR light therapy. The remaining visits were conducted following ≥2 weeks of noise rest in a cross-over design (i.e., those who had received Active NIR light therapy in Visits 1 and 2 received Sham therapy in Visits 3 and 4).
UNASSIGNED: Recovery hearing tests and DPOAEs were completed at the end of each visit. Participants experienced temporary threshold shifts (TTS) immediately following noise exposure, with a mean shift of 6.79 dB HL (±6.25), 10.61 dB HL (±6.89), and 7.30 dB HL (±7.25) at 3000, 4000, and 6000 Hz, respectively, though all thresholds returned to baseline at 3000, 4000, and 6000 Hz within 75 min of noise exposure. Paradoxically, Active NIR light therapy threshold shifts were statistically higher than Sham therapy at 3000 Hz (p = 0.04), but no other differences were observed at the other frequencies tested. An age sub-analysis demonstrated that TTS among younger adults were generally larger in the Sham therapy group versus Active therapy, though this was not statistically different. There were no differences in CPATB test results across Active or Sham groups. Finally, we observed no changes in auditory function or central processing following noise exposure, suggestive of healthy and resilient inner ears.
UNASSIGNED: In this study, locally administered NIR prior to noise exposure did not induce a significant protective effect in mitigating noise-induced TTS. Further exploration is needed to implement effective dosage and administration for this promising otoprotective therapy.