The human ear is an intricate creation that begins to form cells in the embryo at about 5 weeks, allowing the baby to begin hearing sounds at 18 weeks of pregnancy. In life, hearing makes it possible to engage, listen, communicate, laugh, and enjoy many of the things that help shape our quality of life.

Hearing is essential for maintaining relationships and connections with friends and family, fully participating in team and community activities, experiencing life events and so much more. Furthermore, hearing allows one to orient oneself, identify and recognize objects in the world based on the sound they produce. In addition to our ears, we also “hear” through our skin and bones, and hearing is said to be the last sense that leaves us as we transition at the end of our lives.

The intricate connection between sound and health extends beyond auditory implications, resonating throughout our entire being. From the soothing melodies of a blackbird's song to the rhythmic hum of a passing train, vibrations in the air, ground, or water create a well-rounded symphony that impacts our well-being. When sounds enter your ear, they trigger vibrations of tiny membranes, bones, and hair cells inside, which generate electrical signals interpreted by your brain as sound. Hence, extremely loud and/or frequent sounds can have the tendency to hurt the human body. One of the largest nerves in the human body is connected to the ear, here is more on the vagus nerve.

Noise Pollution

Erica Walker, an epidemiologist at Brown University, emphasizes that excessive or recurrent loud sounds can harm not only our hearing, the membranes, hair cells or nerves that enable us to hear, but also disrupt our sleep and trigger a torrent of health issues. Chronic exposure to loud environments activates a stress response, akin to a fight-or-flight reaction. Walker explains that while an isolated encounter may not be alarming, constant stimulation of this stress response, due to chronic noise exposure, can lead to severe health outcomes, particularly in the cardiovascular domain. When that stress response is stimulated, breathing and heart rates begin to increase and the body is releasing all sorts of stress hormones, among them adrenaline and cortisol.

The Centers for Disease Control and Prevention estimates that as many as 22 million Americans are exposed to noise pollution at work each year, and fortunately, scientists are learning more about how sound can impact human health all the time.

In the United States, the National Institute for Occupational Safety and Health (NIOSH) sets guidelines to safeguard against noise-related health risks at a workplace. As a result, it recommends limiting exposure to sounds louder than 85 dB - similar to power tools, lawnmowers or vacuum cleaners - for no more than eight hours in order to minimize occupational noise induced hearing loss. To put that into perspective, sounds in this range would require you to shout in order to be heard by someone being about three feet away.

Furthermore, the duration of exposure should decrease as the volume increases, underscoring the importance of preserving a tolerable or tranquil soundscape. For sounds that approach 100 dB - such as a construction site - the NIOSH suggests just 15 minutes of exposure without ear protection.

For those participating in gong baths, sound bath meditations or other sound related activities, maintaining a serene auditory environment should be important to the provider and participant alike. Ideally the soundscape should not exceed 80 - 85 dB. We do seldom exceed 80 dB while providing multi layered harmonious sounds from gongs, drums, flutes, the didgeridoo and other instruments. In case you are uncertain, we recommend your use of readily available apps to measure the decibels of any given environment.

Hearing and sleep

The intricate interplay between noise and sleep takes center stage in the pursuit of a holistic lifestyle and sought after prolonged states of well-being. Sleep, a vital pillar of health, supports learning, memory consolidation, cellular growth, and repair. Yet, according to one estimate, chronic noise exposure leads to 48,000 new cases of heart disease in Europe each year and affects the quantity and quality of sleep for 6.5 million people. Noise can raise your blood pressure and heart rate even while you sleep, which can also be associated with lower birth weights in infants or Type 2 diabetes. Additionally, there can be a psychological aspect at play, especially if people feel like they have no control over the noise they are exposed to. According to Walker, this can lead to mental health harms, such as increased anxiety and depression.

Chandra Jackson, a principal investigator at the National Institutes of Health, emphasizes that sleep disruptions, often caused by noise, can lead to physiological effects such as blood vessel dysfunction and changes in glucose metabolism and appetite regulation. Sleep is essential for healing as it also supports the body to clear toxins from the brain and bolster the immune system.

Nighttime noise can fragment sleep structure by inducing awakenings, creating difficulties with falling asleep, and shifting to lighter, less restorative sleep. Chronically disrupted sleep is associated with a variety of negative health outcomes, including obesity, hypertension and poorer cognitive function, in addition to the ones mentioned above.

During sleep, noises don’t have to be loud to cause problems. Depending greatly on the individual’s acoustic sensitivity, sounds as low as 30 to 40 dB (sounds as quiet as a soft whisper) can cause a person to toss and turn or wake up, whereas adverse health effects are observed at night noises in the range of 40 to 55 dB or more. A chart that shows the various decibel ranges can be found here.

Studies suggest that in order to safeguard against noise disturbances during sleep, one may consider incorporating white noise or, modifying the bedroom with soft surfaces, i.e. curtains, pillows, wall decorations etc.

Interestingly, the ability of noise to interfere with sleep has evolutionary roots. Even during sleep, our ears remain vigilant, scanning the night for potential threats. Sleeping in an environment free from disruptive noise ensures a restorative and deeply beneficial experience.

Individual sensitivities

Understanding noise pollution's subjective nature is pivotal. Walker notes that individual perceptions of sound versus noise are influenced by life experiences, individual sensitivities and preferences, as well as culture. What may be considered peaceful for one person might be chaotic for another. This awareness is vital for communities participating in holistic practices, such as sound baths, where sensibly creating a serene auditory space aligns with the diverse experiences of individuals.

Scientists are uncovering evidence that certain communities face more frequent noise exposure, with studies suggesting higher noise levels in areas with diverse socioeconomic backgrounds. For instance, one 2017 study found that both daytime and nighttime noise levels tended to be higher on city blocks with higher proportions of non-white and lower-socioeconomic status residents.

Rural settings, often assumed to be quieter, can be surprisingly loud due to factors such as 24/7 operation of distribution plants. This insight prompts us to reflect on the need for balanced urban planning that prioritizes peace and quiet.

Protecting oneself from noise pollution becomes an integral part of the holistic journey. Depending on your situation, activities and severity of prolonged exposure to loud noises, utilizing earplugs or noise-cancelling headphones can be helpful for creating an auditory environment conducive to your health.

However, as you may imagine, caution is advised when using headphones for loud music as they may contribute to sound-induced conditions like tinnitus, where one’s ears sound like they’re ringing, buzzing, or roaring. Tinnitus is something a person can get after 20 years working at a plant, or 15 years in the military. Nowadays, children that are 10 years old have tinnitus.

The World Health Organization underscores the risk of hearing loss in young individuals due to chronic noise exposure, and estimates that 1.1 billion young people between the ages of 12 and 35 are at risk of hearing loss due to chronic noise exposure including personal audio devices.

Of course, the best way to fight back against noise pollution is to target the source, but this is also the most difficult when confronting sounds emitted from railways, airports, highways, or agricultural and industrial centers. The loudness in our cities comes from very disastrous urban planning, something that calls to be changed going forward.

In conclusion

As advocates and practitioners for holistic well-being, we encourage you to be mindful when subjecting yourself to sound. While there are many guidelines, in the end only you can determine what “loud” means, and most importantly, feels like to you.

To experience the difference of soothing vs. aggressive sounds we invite you to listen to these sound bites toward the lower part of this page. Or just simply go to the forest or nearby forest preserve to enjoy the relative stillness, while understanding that there are no naturally quiet places left on Earth as human-made noise, usually in the form of transportation (by highway, rail, air, and boat) pervades every corner of the planet. However, you will notice the immediate positive effects that being in the natural environment provides. More on the ancient practice of forest bathing here.

Addressing the root causes of noise pollution is vital. Targeting sources such as railways, airports, highways, and industrial centers requires collective efforts. There is also the need to acknowledge and rectify the consequences of urban planning that has inadvertently contributed to the loudness in our cities.

In embracing a holistic approach to well-being, we all can play an active role in nurturing environments that resonate with tranquility and harmony. Beginning with the space between our ears, because “undesirable noise” can also be inaudible, generated by thoughts alone.