Last week we discussed how noise can be toxic to our well-being. This week we will look at the impact noise can have on our health. Hearing problems affect 1 in 6 Australians. Hearing problems include hearing loss, difficulties in understanding speech in noise, tinnitus and hyperacusis.
Noise induced hearing loss
The most obvious effect of noise is damage to the ears when it is too loud.
Our ears are very sensitive, and can be easily damaged when exposed to loud or sustained noise. An explosion is an impulse sound. Loud music through headphones or at concerts is sustained sound. Both can damage the ears, in the same way, causing noise-induced hearing loss. The louder the sound, or the closer you are to it, the less time it takes for damage to occur.
Hearing loss after exposure to loud noises can be temporary, lasting up to 48 hours, or be permanent. Even when it is temporary the damage is cumulative and can still lead to hearing loss in the future.
Our ears are the only sense that truly works 24 hours a day 7 days a week. Our brain constantly processes and interprets sound, even while we sleep. Even normal sounds that we are accustomed to trigger a response. The most obvious effect of this is disturbed sleep.
Sleep disruption leads to tiredness, impaired memory and creativity, and impaired judgement. The state of hyper-arousal it causes can also trigger an acute stress response. This raises blood pressure and heart rate. This can lead to increased cortisol levels at night, causing disturbance to the circadian rhythm.
Sleep disturbance can occur with noise levels as low as 35dB. That is about the level of a whisper, and slightly less than a computer or refrigerator running.
While we have already discussed the impact a disrupted circadian rhythm can have on our health, it is worth mentioning again that the effects include heart disease, higher risk of stroke, diabetes, inflammation, decreased immune function and high blood pressure.
There have been numerous studies on the effects of noise pollution in urban environments. They have repeatedly shown a direct association between exposure to road traffic and aircraft noise and hypertension and ischaemic heart disease. A study in Europe showed that those living near an airport had a 28 percent increase in anxiety medication use. Similarly, those who live in busy urban areas are 25 percent more likely to have symptoms of depression than those living in quieter neighbourhoods.
Sound hypersensitivity and hormones.
Last week we briefly discussed sound hyper-sensitivity and its relationship to hormones and stress levels.
While the link between noise and stress hormones is more clear, the role oestrogen plays in hearing and hypersensitivity is not yet fully understood. In saying that, there clearly is a link.
Sensitivity is most obvious in women with extreme emotional exhaustion and stress can play a large role in hormonal disruption. When we are under pressure or extreme stress even the slightest noise can drive us to distraction. Something as small as a ticking clock can seem twice as loud.
Studies have shown an increase in tinnitus and noise sensitivity during menstruation as well as after menopause. This correlates with a woman’s natural decline in oestrogen and further affirms a link between them.
Sound can affect so much more than just our hearing, and toxic to so many body systems. Come back next week when we will talk about how to reduce the effect of noise as a stress to your health and find ways to restore some quiet in our lives.