9:59:59.000,9:59:59.000 Do you hear that? 9:59:59.000,9:59:59.000 Do you know what that is? 9:59:59.000,9:59:59.000 Silence. 9:59:59.000,9:59:59.000 The sound of silence. 9:59:59.000,9:59:59.000 Simon and Garfunkel wrote a song about it, 9:59:59.000,9:59:59.000 but silence is a pretty[br]rare commodity these days, 9:59:59.000,9:59:59.000 and we're all paying a price for it[br]in terms of our health, 9:59:59.000,9:59:59.000 a surprisingly big price, as it turns out. 9:59:59.000,9:59:59.000 Luckily, there are things[br]we can do right now, 9:59:59.000,9:59:59.000 both individually and as a society, 9:59:59.000,9:59:59.000 to better protect our health 9:59:59.000,9:59:59.000 and give us more of the benefits[br]of the sounds of silence. 9:59:59.000,9:59:59.000 I assumed that most of you know that[br]too much noise is bad for your hearing. 9:59:59.000,9:59:59.000 Whenever you leave a concert or a bar[br]and you have that ringing in your ears, 9:59:59.000,9:59:59.000 you can be certain that you have done[br]some damage to your hearing, 9:59:59.000,9:59:59.000 likely permanent, 9:59:59.000,9:59:59.000 and that's very important. 9:59:59.000,9:59:59.000 However, noise affects our health[br]in many different ways beyond hearing. 9:59:59.000,9:59:59.000 They're less well known, 9:59:59.000,9:59:59.000 but they're just as dangerous[br]as the auditory effects. 9:59:59.000,9:59:59.000 So what do we mean[br]when we talk about noise? 9:59:59.000,9:59:59.000 Well, noise is defined as unwanted sound, 9:59:59.000,9:59:59.000 and as such both has[br]a physical component, with sound, 9:59:59.000,9:59:59.000 and a psychological component, 9:59:59.000,9:59:59.000 the circumstances that make[br]the sound unwanted. 9:59:59.000,9:59:59.000 A very good example is a rock concert. 9:59:59.000,9:59:59.000 A person attending the rock concert[br]being exposed to 100 decibels 9:59:59.000,9:59:59.000 does not think of the music as noise. 9:59:59.000,9:59:59.000 This person likes the band, and even[br]paid a hundred dollars for the ticket, 9:59:59.000,9:59:59.000 so no matter how loud the music,[br]this person doesn't think of it as noise. 9:59:59.000,9:59:59.000 In contrast, think of a person living[br]three blocks away from the concert hall. 9:59:59.000,9:59:59.000 That person is trying to read a book, 9:59:59.000,9:59:59.000 but cannot concentrate[br]because of the music, 9:59:59.000,9:59:59.000 and although the sound pressure levels[br]are much lower in this situation, 9:59:59.000,9:59:59.000 this person still thinks[br]of the music as noise, 9:59:59.000,9:59:59.000 and it may trigger reactions that can,[br]in the long run, have health consequences. 9:59:59.000,9:59:59.000 So why are quiet spaces so important? 9:59:59.000,9:59:59.000 Because noise affects our health[br]in so many ways beyond hearing. 9:59:59.000,9:59:59.000 However, it's becoming[br]increasingly difficult 9:59:59.000,9:59:59.000 to find quiet the spaces, 9:59:59.000,9:59:59.000 in a time with constantly[br]increasing traffic, 9:59:59.000,9:59:59.000 growing urbanization, 9:59:59.000,9:59:59.000 construction sites,[br]air conditioning units, 9:59:59.000,9:59:59.000 leaf blowers, lawnmowers, 9:59:59.000,9:59:59.000 outdoor concerts and bars,[br]personal music players, 9:59:59.000,9:59:59.000 and your neighbors partying until 3AM. 9:59:59.000,9:59:59.000 Whew. 9:59:59.000,9:59:59.000 In 2011, the World Health Organization[br]that 1.6 million healthy life years 9:59:59.000,9:59:59.000 are lost every year due to exposure[br]to environmental noise 9:59:59.000,9:59:59.000 in the Western European[br]member states alone. 9:59:59.000,9:59:59.000 One important effect of noise[br]is that it disturbs communication. 9:59:59.000,9:59:59.000 You may have to raise your voice[br]to be understood. 9:59:59.000,9:59:59.000 In extreme cases, you may even[br]have to pause the conversation. 9:59:59.000,9:59:59.000 It's also more likely to be misunderstood[br]in a noisy environment, 9:59:59.000,9:59:59.000 and these are all likely reasons[br]why studies have found that children 9:59:59.000,9:59:59.000 who attend schools in noisy areas 9:59:59.000,9:59:59.000 are more likely to lag behind their peers[br]in academic performance. 9:59:59.000,9:59:59.000 Another very important[br]health effect of noise 9:59:59.000,9:59:59.000 is the increased risk[br]for cardiovascular disease 9:59:59.000,9:59:59.000 in those who are exposed[br]to relevant noise levels 9:59:59.000,9:59:59.000 for prolonged periods of time. 9:59:59.000,9:59:59.000 Noise is stress, 9:59:59.000,9:59:59.000 especially if we have little[br]or no control over it. 9:59:59.000,9:59:59.000 Our body excretes stress hormones[br]like adrenaline and cortisol 9:59:59.000,9:59:59.000 that lead to changes[br]in the composition of our blood 9:59:59.000,9:59:59.000 and in the structure of our blood vessels, 9:59:59.000,9:59:59.000 which have been shown to be stiffer[br]after a single night of noise exposure. 9:59:59.000,9:59:59.000 Epidemiological studies show association[br]between the noise exposure 9:59:59.000,9:59:59.000 and an increased risk[br]for high blood pressure, 9:59:59.000,9:59:59.000 heart attacks and stroke, 9:59:59.000,9:59:59.000 and although the overall[br]risk increases are relatively small, 9:59:59.000,9:59:59.000 this still constitutes[br]a major public health problem 9:59:59.000,9:59:59.000 because noise is so ubiquitous 9:59:59.000,9:59:59.000 and so many people are exposed[br]to relevant noise levels. 9:59:59.000,9:59:59.000 A recent study found that US society 9:59:59.000,9:59:59.000 could save 3.9 billion dollars each year 9:59:59.000,9:59:59.000 by lowering environmental[br]noise exposure by five decibels 9:59:59.000,9:59:59.000 just by saving costs for treating[br]cardiovascular disease. 9:59:59.000,9:59:59.000 There are other diseases[br]like cancer, diabetes, and obesity 9:59:59.000,9:59:59.000 that have been linked to noise exposure, 9:59:59.000,9:59:59.000 but we do not have enough evidence yet 9:59:59.000,9:59:59.000 to in fact conclude that these diseases[br]are caused by the noise. 9:59:59.000,9:59:59.000 yet another important effect[br]of noise is sleep disturbance. 9:59:59.000,9:59:59.000 Sleep is a very active mechanism[br]that recuperates us 9:59:59.000,9:59:59.000 and prepares us for the next wake period. 9:59:59.000,9:59:59.000 A quiet bedroom is a cornestone[br]of what sleep researchers call 9:59:59.000,9:59:59.000 "a good sleep hygiene." 9:59:59.000,9:59:59.000 And our auditory system[br]has a watchman function. 9:59:59.000,9:59:59.000 It's constantly monitoring[br]our environment for threats, 9:59:59.000,9:59:59.000 even while we're sleeping. 9:59:59.000,9:59:59.000 So noise in the bedroom can cause a delay[br]in the time it takes us to fall asleep, 9:59:59.000,9:59:59.000 it can wake us up during the night, 9:59:59.000,9:59:59.000 and it can prevent our blood pressure[br]from going down during the night. 9:59:59.000,9:59:59.000 We have the hypothesis that[br]if these noise-induced sleep disturbances 9:59:59.000,9:59:59.000 continue for months and years, 9:59:59.000,9:59:59.000 then an increased risk for cardiovascular[br]disease is likely the consequence. 9:59:59.000,9:59:59.000 However, we are often not aware[br]of these noise-induced sleep disturbances 9:59:59.000,9:59:59.000 because we are unconscious[br]while we're sleeping. 9:59:59.000,9:59:59.000 In the past, we've done studies[br]on the effects of traffic noise on sleep, 9:59:59.000,9:59:59.000 and research subjects would often[br]wake up in the morning and say, 9:59:59.000,9:59:59.000 "Ah, I had a wonderful night,[br]I fell asleep right away, 9:59:59.000,9:59:59.000 never really woke up." 9:59:59.000,9:59:59.000 When we would go back[br]to the physiological signals 9:59:59.000,9:59:59.000 we had recorded during the night, 9:59:59.000,9:59:59.000 we would often see numerous awakenings 9:59:59.000,9:59:59.000 and a severely fragmented sleep structure. 9:59:59.000,9:59:59.000 These awakenings were too brief[br]for the subjects to regain consciousness 9:59:59.000,9:59:59.000 and to remember them[br]during the next morning, 9:59:59.000,9:59:59.000 but they may nevertheless[br]have a profound impact 9:59:59.000,9:59:59.000 on how restful our sleep is. 9:59:59.000,9:59:59.000 So when is loud too loud? 9:59:59.000,9:59:59.000 A good sign of too loud is[br]once you start changing your behavior. 9:59:59.000,9:59:59.000 You may have to raise your voice[br]to be understood, 9:59:59.000,9:59:59.000 or you increase the volume of your tv. 9:59:59.000,9:59:59.000 You're avoiding outside areas[br]or you're closing your window. 9:59:59.000,9:59:59.000 You're moving your bedroom[br]to the basement of the house, 9:59:59.000,9:59:59.000 or you even have[br]sound insulation installed. 9:59:59.000,9:59:59.000 Many people will move away[br]to less noisy areas, 9:59:59.000,9:59:59.000 but obviously not everybody[br]can afford that. 9:59:59.000,9:59:59.000 So what can we do right now 9:59:59.000,9:59:59.000 to improve our sound environment[br]and to better protect our health? 9:59:59.000,9:59:59.000 Well, first of all,[br]if something's too loud, speak up. 9:59:59.000,9:59:59.000 For example, many owners of movie theaters 9:59:59.000,9:59:59.000 seem to think that only people hard[br]of hearing are still going to the movies. 9:59:59.000,9:59:59.000 If you complain about the noise[br]and nothing happens, 9:59:59.000,9:59:59.000 demand a refund and leave. 9:59:59.000,9:59:59.000 That's the language that managers[br]typically do understand.