My TED talk on sound and health has created a lively debate, I am delighted to say: my intention was precisely to get people thinking and talking about sound and its effects on health. I wish I'd had more time during the talk to give references for the claims and assertions I made, and one purpose of this blog is to offer those for anyone who is interested in knowing more.
This is also for all those who seem hung up on the concept of proof, and have used the term 'pseudoscience' in what feels like the same way the word 'witch' was used in Europe and the US. It's sufficient to damn, and no evidence is required - ironic given that it is itself an accusation of lack of evidence. This is concerning, because of course the scientific method is not at all concerned with proof: it operates by people proposing hypotheses and then testing them to destruction. There is no proof in empirical science; there is only a current absence of dis-proof. An approach which dismisses any idea or hypothesis because it's not 'scientific' is itself anti-scientific! The true scientific response is to take the idea and then devise ways of testing it. Out-of-hand dismissal is the real pseudo-science.
In a wider context, the stance that assertions are acceptable only if backed by evidence also denies some of the more interesting areas of human thought, such as philosophy and religion, not to mention large parts of the social sciences and much of modern physics and cosmology. Any comprehensive study of sound and music touches on many other areas of study, such as physics, psychology, sociology, anthropology and neuroscience, and so must involve considering many theses and ideas that are untestable, or at least currently untested. I was surprised by the vehemence of some of the feedback to my talk, where people seemed very angry in dismissing assertions that lacked sources rather than investigating them, and where the very mention of the tradition of sound healing was enough to damn the whole talk as 'new age' - another of the heinous condemnations deemed sufficient for instant dismissal by the pseudo-science wolves. I like this perspective from the eminent psychologist Carl Seashore:
"Practically, metaphysics and philosophy proper are not separated, and they are not marked off in sharp distinction from science, on the one hand and common sense, on the other. In fact the historical development of any question, such as the nature of musical value, arises as the main question and soon takes on both metaphysical and supernatural interpretations. These are criticized in philosophy and gradually analyzed and clarified by scientific methods; this done, the information tends to be regarded as a matter of common knowledge or common sense." (Seashore CE 1938 Psychology of music. New York, McGraw-Hill p376)
I hope that my talk opens the minds of those who had dismissed the idea that sound can improve (or damage) health, and connects them with the work mentioned in this blog. And I hope that science does much more testing on the effects of sound on health so that we can see evidence for some of the hypotheses I put forward in the talk.
Let me give some background to each of the assertions I made, and clarify where I was suggesting a hypothesis or just giving a personal opinion.
"Nada brahma - the world is sound" is actually the title of a fascinating book by Joachim-Ernst Berendt. It spans science, religion and philosophy, and is thought-provoking throughout. Warning: much of it is 'unproven'!
Vibration / you are a chord - this is obvious from physics, though it's admittedly somewhat metaphorical to call the combined rhythms and vibrations within a human being a chord, which we understand to be an aesthetically pleasant audible collection of tones. But "the fundamental characteristic of nature is periodic functioning in frequency, or musical pitch." (Eagle CT 1991 The quantum reality of music. In Music education; Why? What? How? ed S Hauptfleisch p 43-66, South Africa, HSRC Publications). Matter is vibrating energy; therefore, we are a collection of vibrations of many kinds, which can be considered a chord.
Health as harmony of our vibrations. I qualified this carefully to say "one definition of health may be that that chord is in complete harmony." Taking the WHO definition of health ("a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity") opens at least three dimensions to the concept, two of which have nothing to do with the medical profession. This suggested definition of health is not a 'proven' proposition, which is why I qualified so carefully: however it is an interesting idea, still in the first of Seashore's stages of development (above) - and so may be considered supernatural by some until science tests it properly. For more on the idea of vibrational harmony and health, see (Wolf FA 1981 The body quantum: the new physics of body, mind and health. New York, Macmillan) or (Steve Halpern 1985 Sound Health: The music and sounds that make us whole. New York, Harpercollins) and try to set aside anti-'new age' prejudice to find out if there are any interesting ideas in there for you. I think there is plenty in this concept to explore and I hope scientific research turns its attention to the area.
On a philosophical level, Plato, Socrates, Pythagoras and Confucius all wrote at length about the relationship between harmony, music and health (social and physical). Here are a couple of references - there are many!
"Rhythm and harmony find their way into the inward places of the soul, on which they mightily fasten, imparting grace, and making the soul of him who is rightly educated graceful, or of him who is ill-educated ungraceful." (Socrates, in The Republic of Plato 1888 Oxford Clarendon Press p 88)
"The Yi Jing develops the notion of ‘grand harmony’ (tai he). It is the concept that the entire universe constitutes a great harmony. ‘How great is the Qian (Heaven)! From it the myriad things originate under Heaven . . . With the changes of the Qian way, the myriad things all keep on their own path of life. Thus they preserve the grand harmony’ (Yi Jing: Tuan). Accordingly, ‘grand harmony’ is the most important ideal in the Yi Jing. The world is full of different things, yet all these things harmonize as they go through incessant changes. The ‘Yi Jing’ is considered the primary text among all Confucian texts. The notion of ‘grand harmony’ sets the stage for all other Confucian ideals, social as well as individual." (Chenyang Li 2008 The Philosophy of Harmony in Classical Confucianism in Philosophy Compass 3/3 p423–435)
New research by Jay Kennedy here shows that Plato not only wrote about the power of music on society and personal health - he embedded musical structure in his writings.
10 octaves v one octave. An octave is a doubling in frequency. The visual spectrum in frequency terms is 400-790 THz, so it's one octave. Humans with great hearing can hear from 20 Hz to 20 KHz, which is ten octaves.
Listening positions. This is a concept I develop in my book Sound Business - not research-based analysis, just a useful set of perspectives that can help people to be more conscious about their listening. As well as the two I mention in the talk, other listening positions include judgemental (or critical), active (or reflective), passive and so on. Some are well known and widely used; for example, active listening is trained into many therapists and counsellors, as well as forming the backbone of parenting and management systems such as Parent Effectiveness Training). I regret that my humorous explanation using affectionate gender stereotypes offended some among the more politically correct; the audience in the room, and I hope most viewers, found it amusing and the concept useful. I don't believe that generalisations based on gender are by definition sexist - sometimes they can be enlightening and helpful. But that's a whole new debate!
Noise stats. Where to start with the horrendous figures about noise and its effects?
The UK National Noise Attitude Survey (NAS) says that 24% of respondents in Greater London reported that noise spoilt their home life to some extent, with 10% reporting that their home life was spoilt either quite a lot or totally.
The 2000 UK Building Research Establishment report says that 2% of the British population - more than a million people - suffered noise of over 60dBA for 90% of the day. This compares with 1.2% ten years earlier.
The EU says “around 20 percent of the Union's population or close on 80 million people suffer from noise levels that scientists and health experts consider to be unacceptable, where most people become annoyed, where sleep is disturbed and where adverse health effects are to be feared. An additional 170 million citizens are living in so-called 'grey areas' where the noise levels are such to cause serious annoyance during the daytime.” (FUTURE NOISE POLICY European Commission Green Paper Brussels 1996).
The World Health Organization says that "Traffic noise alone is harming the health of almost every third person in the WHO European Region. One in five Europeans is regularly exposed to sound levels at night that could significantly damage health." Check the WHO website for more.
My claim about 25% of Europeans suffering from debilitating noise comes from the WHO study Community Noise by Birgitta Berglund and Thomas Lindvall Stockholm, Sweden, 1995: "Almost 25% of the European population is exposed, in one way or another, to transportation noise over 65 dBA (an average energy equivalent to continuous A-weighted sound pressure level over 24 hours) (Lambert & Vallet, 1994). This figure is not the same all over Europe. In some countries more than half of the population is exposed, in others less than 10%. When one realizes that at 65 dBA sound pressure level, sleeping becomes seriously disturbed and most people become annoyed, it is clear that community noise is a genuine environmental health problem."
The WHO is also the source for the startling estimate about noise killing 200,000 people a year. Noise does not just annoy; it increases the risk of death significantly. The WHO LARES report, available here, proves that noise causes many illnesses. It concludes: "...for noise induced sleep disturbances, traffic noise annoyance and neighbourhood noise annoyance, the identified health effects are independent of socio-economic status and housing conditions. The elevated relative risks are expressed in the cardiovascular system, the respiratory system and the musculoskeletal system, as well as through depression." The WHO findings estimate that 3% of deaths from ischaemic heart disease result from long-term exposure to noise. With 7 million deaths a year globally, that means 210,000 people a year are dying of noise. (I said 200,000 in Europe - my apologies for that error; hard to remember every fact perfectly in the pressure of a short TED talk. Nevertheless, even globally this is a horrifying number!)
A wide variety of studies have examined the question of the external costs of noise to society especially transport noise. The estimates range from 0.2% to 2% of GDP. The EU says: "It can be generally concluded from the present state of knowledge that exposure to environmental noise acts as a stressor to health as it may lead to measurable changes in e.g. blood pressure, heart rate, vasoconstriction, endocrine excretion levels and admission rates to mental hospitals... Present economic estimates of the annual damage in the EU due to environmental noise range from EUR 13 billion to 38 billion. Elements that contribute are a reduction of housing prices, medical costs, reduced possibilities of land use and cost of lost labour days.” (Future Noise Policy European Commission Green Paper 1996).
According to a 1999 U.S. Census report, Americans named noise as the number one problem in neighborhoods. Of 102.8 million reporting households, 11.6 million (11.3%) stated that street or traffic noise was bothersome, and 4.5 million (4.4%) said it was so bad that they wanted to move. For the category "other bothersome conditions," 2.7 million (2.6%) named noise. Additionally, 5.3 million (5.1%) said that they were bothered by building neighbornoise. More Americans are bothered by noise than by crime, odors, and other problems listed under "other bothersome conditions."
Then there is noise and society, with its effect on behaviour. The US report Noise and its effects (Administrative Conference of the United States, Alice Suter, 1991) says: "Even moderate noise levels can increase anxiety, decrease the incidence of helping behavior, and increase the risk of hostile behavior in experimental subjects. These effects may, to some extent, help explain the "dehumanization" of today's urban environment."
Maybe Confucious and Socrates had a point.
Schizophonia. As I did credit in the talk, this word was coined by the great Canadian audiologist Murray Schafer. In his essential book The Tuning of the World (1977) Schafer says: "I coined the term schizophonia in The New Soundscape [an earlier book] intending it to be a nervous word. Related to schizophrenia, I wanted it to convey the same sense of aberration and drama. Indeed, the overkill of hi-fi gadgetry not only contributes generously to the lo-fi problem, but it creates a synthetic soundscape in which natural sounds are becoming increasingly unnatural while machine-made substitutes are providing the operative signals directing modern life" (p 91). Schafer was always concerned about the 'hi-fi' quality of natural sound being displaced by the 'lo-fi' quality of much recorded sound - and that was before digital audio and compression were invented. My assertion that continual schizophonia is unhealthy is an opinion, stated as such - and possible a hypothesis that science could and should test. You only have to consider the strange, unreal jollity of train carriages now - full of lively conversation but none of it with anyone else in the carriage - to entertain the possibility that this is somehow unnatural. Old-style silence at least had the virtue of being an honest connection with those around us. Now we ignore our neighbours, merrily discussing intimate details of our lives as if the people around us simply don't exist. Surely this is not a positive social phenomenon? Again, research is required.
Compressed music. However clever the technology and the psychoacoustic algorithms applied, there are many issues with data compression of music, as superbly discussed in this excellent article by Robert Harley back in 1991. My example of course failed to transfer into the video, since all the audio is compressed for the web! It did work in the room. I have posted the sound here if you want to listen on headphones or decent loudspeakers and see if you can spot the difference. My assertion that listening to highly compressed music makes people tired and irritable is a hypothesis based on personal and anecdotal experience - and again it's one that I hope will be tested by researchers.
Hearing loss and headphone abuse. Over 19% of American 12-19 year olds exhibited some hearing loss in 2005-2006 - an increase of almost 5% since 1988-94. (Change in Prevalence of Hearing Loss in US Adolescents, Josef Shargorodsky, MD, MPH; Sharon G. Curhan, MD, ScM; Gary C. Curhan, MD, ScD; Roland Eavey, MD, SM JAMA. 2010;304(7):772-778), reported with comments from the researchers here.
The university study with 61% of freshmen showing hearing loss is from The Power Of Sound (Joshua Leeds 2001, Healing Arts Press p 92).
The rule of thumb that your headphones are too loud if you can't hear someone talking loudly to you over them is fairly common among audiologists. For example, Robert Fifer, an associate professor of audiology and speech pathology at the University of Miami Leonard M. Miller School of Medicine, says: "The ear doesn't care what kind of sound it is, it really only cares how loud that sound is and for what time duration." Fifer advises keeping the volume at a level where you can still hear conversation around you. "If you can still hear what people are saying around you, you are at a safe level," he says. "If the volume is turned so loudly that you can no longer hear conversation around you, or if someone has to shout at you at a distance of about 2 feet or 3 feet to get your attention, then you are up in the hazardous noise range."
The assertions that WWB and silence are good for you seem to be uncontroversial. Perhaps they resonate with everyone's experience.
Sound healing. This seems to have been a red rag to many of the 'pseudoscience' bulls. I was including music therapy and sound therapy in the one category. Music therapy is a well-established form of treatment in the context of mainstream medicine for many conditions, including the ones I mention (dementia, autism). Just Google 'music therapy' and you will find a wealth of references and case studies. Here are a few:
Katagiri J. The effect of background music and song texts on the emotional understanding of children with autism. J Music Ther. 2009 Spring;46(1):15-31.
Kim J. et al. Emotional, motivational and interpersonal responsiveness of children with autism in improvisational music therapy. Autism. 2009 Jul;13(4):389-409.
Stephens CE. Spontaneous imitation by children with autism during a repetitive musical play routine. Autism. 2008 Nov;12(6):645-71.
Music therapy is the use of music to improve health. Less mainstream, though intellectually no more difficult to accept, is sound healing: the use of tones or sounds to improve health through entrainment (affecting one oscillator with a stronger one). This is a very old practice: shamanic and community chant, as well as various resonators like bells and gongs, date back to the earliest societies and are still in use in many cultures around the world. Just because something is old and not done in hospitals doesn't mean that it's 'new-age BS' as some have commented. Doubtless there are charlatans offering snake oil (as in many fields) but I suspect there is much to investigate, and just as herbal medicine gave rise to many of the drugs we use today, I suspect there are rich resources and fascinating insights to be gleaned when science starts to unpack the traditions of sound healing.
Music made with love. Duke Ellington claimed there are only two kinds of music: "good, and the other kind". I suggest an alternative split: music made with love, and the rest. I agree with Manfred Clynes (check out his interesting theory of essentic forms) that music is an excellent transmitter of emotions - in other words people can receive the feeling that went into the making of it. That's what I meant when I recommended listening to music that was made with love - by which I do not mean the people involved were in a blissful state; I just mean that they cared about the outcome and were making it for its own sake, not for some other reason (such as money, status or contractual obligation).
I do think you can tell the difference - and I think it has a different effect on the listener. I was rushing to finish the talk at this point, so I couldn't qualify my specific recommendations: of course Mozart and devotional music are just some of the varieties that are often recommended by expert listeners such as Tomatis. I didn't mean to dictate taste to anyone - many kinds of music can be good for you (and what that means is highly contextual). But if health is equated with lack of stress, then it's hard to see how prolonged listening to music like rap and metal, with their prevailing emotional charge of anger and aggression respectively, can have a positive impact. There is plenty of research on this general area: for example see Heavy Metal Music And Adolescent Suicidality: An Empirical Investigation, which includes further references. Personal variations are huge of course, and I have no doubt that for some people listening to death metal is health-enhancing. However, as a rule I expect that further research will show that music with a positive emotional charge is better for the health than "the other kind".
Musicians have bigger brains. This is slightly misleading as one commentator pointed out. A study by Heidelberg University's Schneider found that people with musical experience had larger amounts of grey matter in the region called the Heschl's gyrus. The structure contained 536 to 983 cubic mm of grey matter in professional musicians and 172 to 450 cubic mm in non-musicians. (Nature Neuroscience, 2002). This does not mean that all musicians have bigger brains than everyone else, just that music leads to an increase in size in this area. However, other things being equal, it does mean that practising music as I suggest will increase the size of a person's brain.
I hope this helps answer some of the queries raised by viewers, and makes a contribution raising awareness of sound and its effects on health. I welcome your thoughts!