A

A

Humans are finely attuned to noise, and for good reason. From an evolutionary perspective, sounds give us vital information, helping us navigate the world and avoid danger. To help ensure loud or unexpected noises get the attention they deserve, our internal chemistry alters in response to them. Our blood pressure goes up, muscles tense and glands release hormones that prepare us for fight or flight. In the short term, this is a good thing. When we are exposed to too much noise over the long term, however, those responses can lead to a multitude of health issues, from sleep disturbance to even cardiovascular disease.

人类对噪音极为敏感，这并非没有道理。从进化的角度来看，声音为我们提供了至关重要的信息，帮助我们感知世界并避开危险。为了确保响亮或突发的噪音能引起我们的注意，我们的身体会做出相应的化学反应：血压升高、肌肉紧张，腺体分泌激素，使我们进入战斗或逃跑的状态。短期内这种反应是件好事。然而，如果长期暴露在过大的噪音环境中，这些反应可能会引发多种健康问题，从睡眠障碍到心血管疾病甚至更严重的问题。

B

B

The World Health Organization has recently designated excessive noise as an 'underestimated threat' to public health, and has said that people living in cities such as Mumbai, Tokyo and Buenos Aires are being exposed to far more than the recommended 40 decibels of noise at night. A report from the European Environment Agency concluded that noise was an ongoing and widespread issue in Europe, with at least 1 in 5 people consistently exposed to levels considered harmful to health. "There are no "earlids" that can protect your brain from noise,' says Nick Antonio, an acoustic consultant who has contributed to the British and international standards for noise.

世界卫生组织最近将过度噪音列为对公共卫生构成的“被低估威胁”，并指出，居住在孟买、东京和布宜诺斯艾利斯等城市的居民夜间所暴露的噪音水平远超建议的40分贝。欧洲环境署的一份报告指出，噪音是欧洲持续且广泛存在的问题，至少每五人中就有一人长期暴露于被认为有害健康的噪音水平之下。“没有任何‘耳罩’能保护你的大脑免受噪音影响，”参与制定英国及国际噪音标准的声学顾问尼克·安东尼奥表示。

C

C

The good news is that several cities have been working to turn the volume down. One of the first to do so was London. 'By providing recommendations for quieter buses, reducing noise from roads and also controlling noise from aircraft, they were able to make the city quieter, says Antonio. Other cities have introduced noise-reducing road coatings, for instance, alongside greenery that muffles sound. Some solutions are more specific: Washington DC's ban on petrol-powered leaf blowers came into effect recently, while in New York City, legislation has been approved to fine people who modify their vehicles to make them noisier. 'People are seeing the benefits of these more quiet environments in their cities,' Antonio says. 'I expect we will see much more of this in the future.'

好消息是，多个城市已经开始努力降低噪音水平。其中最早采取行动的是伦敦。安东尼奥表示：“通过推荐更安静的公交车、减少道路噪音以及控制飞机噪音，他们成功让城市变得更加安静。” 其他城市也推出了降噪路面涂层，并结合绿化植物来吸收声音。一些措施更为具体：华盛顿特区最近实施了禁止使用燃油吹风机的规定，纽约市则已通过立法，对改装车辆以增加噪音的行为处以罚款。安东尼奥说：“人们正在看到这些更安静的城市环境带来的好处。我预计未来我们会看到更多这样的做法。”

D

D

Researchers are also seeking to understand what aspects of silent experiences are most beneficial to our health. One of the best-researched is the flotation tank: a lightproof, soundproof tank of salt water in which a person floats as a form of deep relaxation. While some people experience altered perception in the tanks, involving subtle humming sounds and visual effects, these effects are benign and do not detract from the benefits of the experience, says Justin Feinstein, a clinical neuropsychologist. When you don't have external sensory stimuli coming in, the brain tries to fill the void to make sense of this dark and silent world, he explains. 'In these tanks, some people can even hear the sound of their eyes blinking, says Feinstein. 'But it is the ability to focus on the breath that helps people reach a relaxed or meditative state.'

研究人员还希望了解静默体验中哪些方面对我们的健康最为有益。其中研究最深入的一种是浮力水箱：一种不透光、隔音的盐水水箱，人们在其中漂浮，以达到深度放松的状态。临床神经心理学家贾斯汀·费因斯坦表示，尽管有些人会在水中感受到感知的改变，例如轻微的嗡鸣声和视觉效果，但这些影响都是无害的，并不会削弱体验带来的益处。他解释说：“当没有外界感官刺激时，大脑会试图填补这种空白，从而理解这个黑暗而寂静的世界。”费因斯坦指出：“在这些水箱中，有些人甚至能听到自己眼睛眨动的声音。但真正帮助人们进入放松或冥想状态的，是专注于呼吸的能力。”

E

E

To further explore flotation tanks as a therapeutic tool, Feinstein and his colleagues recruited 50 people with a variety of conditions related to stress and had them answer a questionnaire prior to and following a flotation session. Participants reported decreases in muscle tension, pain and symptoms of their conditions after a single, 1-hour float, alongside an increase in feelings of relaxation and overall wellbeing.

为了进一步探索浮水疗法作为治疗手段的潜力，费因斯坦及其同事招募了50名患有各种与压力相关疾病的患者，在浮水治疗前后让他们填写问卷。参与者表示，经过一次1小时的浮水体验后，肌肉紧张、疼痛以及病情症状均有所减轻，同时感到放松感增强，整体幸福感也有所提升。

Less is known about what effects sensory deprivation can have on the brain. To investigate, Feinstein's team had 48 people participate in either three 90-minute float sessions or three 90-minute periods of relaxing on a chair which reclined. Participants had their brains scanned using functional magnetic resonance imaging at the beginning and end of the trial. Float sessions uniquely decreased activity in the default mode network (DMN), a collection of brain regions commonly linked with depression.Feinstein says it is an exciting finding, because flotation tanks seem to offer a way of resetting' our nervous system to prevent it from getting out of balance.

目前对感官剥夺对大脑可能产生何种影响仍知之甚少。为进行研究，费因斯坦团队让48名参与者分别参加三次90分钟的漂浮训练，或三次在可调节椅子上放松的90分钟时间。试验开始和结束时，研究人员使用功能性磁共振成像技术扫描了参与者的脑部。结果显示，漂浮训练显著降低了默认模式网络（DMN）的活动水平，而该网络是一组常与抑郁症相关的脑区。费因斯坦表示，这一发现令人振奋，因为漂浮舱似乎能帮助我们重置神经系统，防止其失去平衡。

F

F

Neurobiologist Tal Dotan Ben-Soussan is also an advocate of silence as a therapy.'When we find ways to be quiet, we are not only quiet in our environment, but quiet in our inner selves, she explains. "This allows us to be more aware of what is happening around us and what the situation may require from us so we can provide [a more] adequate response.'

神经生物学家塔尔·多坦·本-苏桑也主张沉默作为一种疗法。“当我们学会保持安静时，不仅是在环境中保持安静，更是在内心深处保持安静，”她解释道，“这使我们能更清楚地意识到周围发生的事情，以及情境可能对我们的要求，从而能够做出更恰当的回应。”

Not everyone will benefit from silence to the same extent, but Ben-Soussan says one characteristic is key: the person must need to want to engage in the experience. 'We see from animal models and human studies that volition and intentionality is important,' she says. 'When people do not want silence, it can be very distressing.'

并非所有人都能以相同程度从沉默中获益，但本-苏桑指出，一个关键特征是：当事人必须真正渴望参与这种体验。“从动物模型和人类研究来看，意愿与主观意图非常重要，”她说，“当人们不希望沉默时，这种状态可能会带来极大的痛苦。”

G

G

Eric Pfeifer, a psychotherapy researcher, also concedes that some people may not benefit from silence, particularly those who are in a heightened state of stress. 'People in these states may not be able to relax or calm down in a silent condition,' he says.Professional guidance can be useful, he adds, allowing people to approach silence slowly so that they can gradually enjoy the benefits. And Pfeifer is convinced that silence is more attainable in everyday life than people think. First, complete silence isn't necessary. In a recent study, he found that participants reported more relaxation and less boredom when they sat quietly in an outdoor garden compared with a completely silent room. Second, Pfeifer believes we don't need a lot of silence to gain benefits. You don't need to spend hours in silence,' he says. 'It is likely better to have more frequency of silence for a few minutes at a time than a longer period of silence only once a week. Just finding those places in your daily life where you can find some silence... can make a big difference.'

心理治疗研究者埃里克·费弗也承认，有些人可能无法从沉默中获益，尤其是处于高度压力状态的人。他说：“处于这种状态的人，在安静的环境中可能难以放松或平静下来。”他补充道，专业指导可以帮助人们逐步接近沉默，从而慢慢享受其中的好处。费弗坚信，日常生活中实现沉默比人们想象的更容易。首先，完全的寂静并非必要。在一项最近的研究中，他发现，参与者在户外花园安静地坐着时，相比完全静音的房间，报告了更多的放松感和更少的无聊感。其次，费弗认为，我们并不需要大量沉默才能获得益处。“你不需要长时间保持沉默，”他说，“每周只一次、持续很长时间的沉默，不如每天多次短暂地体验沉默效果更好。只需在日常生活中找到一些可以拥有片刻宁静的地方……就能带来显著的不同。”