晕动病是一种常见的交通问题,全球范围内影响许多人,尤其是在汽车、船只或飞机旅行中。研究指出,耳石器功能障碍是晕动病的关键病因,而目前缓解晕动病的技术有限。论文《Just 1-min exposure to a pure tone at 100 Hz with daily exposable sound pressure levels may improve motion sickness》探讨了一种新方法:通过短时间暴露于特定频率的纯音来缓解晕动病。
Previous studies physiologically indicated that vibration at 100 Hz could activate not only otolithic functions but also canal afferents [18]. Previous studies morphologically showed that exposure to a pure tone at 100 Hz could modulate vestibular function by affecting the otolith in the inner ears of mice [19–21]. A previous epidemiological study for healthy people showed that exposure to a sound component of 100 Hz in music improved balance function assessed by the envelope area in posturography [22]. These results in mice and humans suggest that the pure tone at 100 Hz can modulate vestibular function. To our knowledge, however, the ranges of frequencies and sound pressure levels of functional sounds that can activate vestibular function have not been clarified.
Vestibular dysfunction-mediated imbalance and subsequent autonomic dysregulation are key etiologies for motion sickness [3–6]. Therefore, a sound that can activate vestibular function may alleviate motion sickness. To validate the hypothesis, we carried out an ex vivo study in mice for screening frequencies (90–1000 Hz) and sound pressure levels (65–85 dBZ) of pure tones that activate vestibular function of the mouse inner ear. We then carried out in vivo studies in mice and humans to clarify whether the selected pure tone with daily exposable sound pressure levels could mitigate motion sickness with focus on imbalance and/or subsequent autonomic dysregulation caused by different kinds of shaking. This study focused on motion sickness induced by side-to-side and up-and-down motions associated with otolithic function rather than by rotation involved in semicircular canal, with the aim of mimicking the shaking of a vehicle. This is the first attempt to create a more comfortable transportation environment with mitigation of motion sickness.