Saturday, November 15, 2014

(Musical) Silence


Source
Galloway, L. (2012, October 23). The quietest place on Earth. BBC Travel. Retrieved from http://www.bbc.com/travel/blog/20121022-the-quietest-place-on-earth

Summary & Commentary
          According to the Guinness Book of World Records, the “quietest place on earth” is an anechoic (echoless) chamber at Orfield Laboratories in Minneapolis, USA.  Its lack of echoes is credited to its construction.  After walking through two vault doors, one-metre long foam wedges line the room’s walls, ceiling, and even bottom; one must walk on a “floor” made of a trampoline-like mesh.  Virtually no sound is reflected off of the walls, which absorb 99.99% of all noise.  High-frequency sounds are directly absorbed by the fibreglass wedges, and low-frequency sounds bounce in between the wedges until they fizzle out.  As a result, its sound level is -9.4 dB (decibels)—humans can only detect sounds above 0 dB.  The decibel level of a room that an average person would consider to be “quiet”, for example, is 30 dB.
In the chamber, not only can you hear a pin drop, but you also start noticing the frenzy of activity that is going on inside your own body.  People have reported hearing their lungs breathing, their own heartbeat, their stomach digesting food, and even hearing the blood rush to their head and back through to their body.  Even ears themselves make sounds in the echoless room.  Steven Orfield, founder and owner of Orfield Laboratories, explains: “The ear is like a microphone and a loudspeaker. And when it is deprived of sound, it produces its own sounds.” (Weber 2012).  Orfield is talking about otoacoustic emissions (OAE) which are sounds generated by various cellular and mechanical processes in the inner ear, and usually go completely unheard by the unknowing public.
Even after about five minutes in the room, people become disoriented, dizzy, nauseous, and feel like there’s tremendous “pressure” on their head.  “What seems to be happening is you are feeling some pressure in your ears,” explains Orfield, “but what you’re really feeling is pressure being taken off of your ears. Sound is technically called sound pressure level. And in this room we’re actually taking huge amounts of pressure off of your ear, so it’s highly sensitized by not being loaded with normal amounts of noise.” (Weber 2012).  People who visit the anechoic chamber usually sit in a chair.  Standing up and moving around becomes increasingly difficult because we rely so heavily on sound to keep our balance.  Walking feels strange because we have no aural reference (or if one is inside the room in the dark, no visual cues either) for mobility.  Without any feedback from the outside world—like the sound of your own feet moving, for example—uninterrupted action is almost impossible.  The chamber also causes many to feel claustrophobic.  Usually reverb or echo tells our auditory system that there is an ample amount of space, thus the complete absence of echo can instinctively send us into a panic.
          Furthermore, once you lose certain sensations, other perceptions become heightened.  A complete absence of noise can lead to a heightened sense of smell or touch, but can also cause your hearing to become much more sensitive.  As we already know, the auditory cortex sorts, organizes, and simplifies sounds.  And many of the bodily noise people report hearing in the echoless chamber would normally be victim to habituation.  We don’t need to hear these things when we’re out in the world and have to be aware of cars, animals, weather, other people, etc.  But when all of those stimuli disappear, undetectably quiet sounds seem louder, as if our brains have recalibrated to the new noise levels.  People have even reported hearing aural hallucinations, although none of my sources have described the nature of them in detail.
          How quiet is too quiet?  For people with sensitive hearing, the chamber might indeed be too quiet and they would have to get out of the room immediately.  The longest amount of time anyone has been able to spend in Orfield Lab’s anechoic chamber without panicking and needing to leave is 45 minutes.

Reflection
          This article made me think about the relationship between silence and music in two different ways: (1) musical auditory hallucinations as a result of silence, and (2) the idea of “musical” silence, or, periods of silence in between notes, phrases, or pieces, inserted for artistic purposes.
As previously mentioned, it is a shame that the alleged “auditory hallucinations” people have had in the Minneapolis anechoic chamber aren’t better documented. What do people come to “hear” without any outside stimulation when left in complete silence?  Do people ever perceive music that isn’t really there? Is it easier to remember or vividly visualize music in silence? Maybe because we’re so used to hearing everyday sounds, that when all of it is taken away we try to make up for what we’re accustomed to by creating the sounds ourselves?  After all, the healthy population is fully capable of recreating sounds—whether it be voices, street noises, or music—in the mind’s ear with minimal effort, so it’s not a far leap to say it can sometimes occur involuntarily due to sensory deprivation. 
          An echoless room is essentially a variation on John C. Lilly’s sensory deprivation tank, which he invented in 1954.  A physician and neuroscientist, Lilly aimed to isolate the brain from any external stimulation.  The small tank, which closes shut to stop any light from getting in, is filled with warm salt water allowing for a subject to float for extended periods of time.  The sensory deprivation tank operates on the principle that in total absence of external stimuli, the human brain creates its own perceptions.  The idea of perceptual isolation is known today as the Restricted Environmental Stimulation Technique (REST) which can occur in a room or in water.  Even with the psychological and neurological research done with REST, there are very few findings about auditory hallucination—or hallucination as a result of sensory deprivation—that doesn’t cross over into issues of psychosis (see Nayani & David 1996; Na & Yang 2009, for example).
Now, knowing everything we’ve just learned about our brain’s reaction to silence, what are the potential applications of silence in music?  And how can silence be used in music for artistic or dramatic purposes?  In “Moved by Nothing,” Margulis explored five functions of silence in active, participatory music listening: (1) silence as boundary, (2) silence as interruption, (3) silence as a revealer of the inner ear, (4) silence as a promoter of meta-listening, and (5) silence as a communicator.  She says that “since literally nothing happens for the extent of the duration of the silence, all of our various percepts, reactions, surmises, and senses reveal things we have brought to the silence.” (Margulis 2007, p.246).
In a setting where one has consciously sat down to listen to music, silence can be extremely powerful.  Like the commanding silence before the beginning of a piece, for example, where every attentive ear is hypersensitive to the slightest sound, getting mentally ready to hear what is to unfold before them.  In line with the anechoic chamber discussion, sounds emerging from silence are actually better processed by our brains, as the search for an auditory stimulus activates the auditory cortex (Voisin et al. 2006).  Moreover, EEG (electroencephalography) and MEG (magnetoelectroencephalography) tests show the brain’s detection of musical phrase boundaries shortly after the phrase’s offset, suggesting that listeners spend these silences synthesizing the preceding musical phrase and refocusing their attention on hearing the subsequent one (Margulis 2007, p.253).
Just like in a sensory deprivation tank, when auditory stimuli are removed in the context of music-listening our own personal auditory imagery, visualizations, imaginings, assumptions, and expectations come to the fore.  Musical silence can definitely serve to encourage this process, additionally acting as a sonic boundary that guides our auditory attention.

References
Margulis, E. H. (2007). Moved by nothing: Listening to musical silence. Journal of Music Theory, 51(2), 245-276.
Na, H.J., & Yang S. (2009). Effects of listening to music on auditory hallucination and psychiatric symptoms in people with schizophrenia. Journal of Korean Academy of Nursing, 39(1), 62-71. http://dx.doi.org/10.4040/jkan.2009.39.1.62
Nayani, T. H., & David, A. S. (1996). The auditory hallucination: A phenomenological survey. Psychological Medicine, 26(01), 177-189. doi:10.1017/S003329170003381X
Veritasium. (2014). Can Silence Actually Drive You Crazy? YouTube. Retrieved from https://www.youtube.com/watch?v=mXVGIb3bzHI
Voisin, J., Bidet-Caulet, A., Bertrand, O., & Fonlupt, P. (2006). Listening in silence activates auditory areas: A functional magnetic resonance imaging study. The Journal of Neuroscience, 26(1), 273-278.
Weber, T. (2012, June 21). In Minneapolis, the world's quietest room. MPR News. Retrieved from http://www.mprnews.org/story/2012/04/03/daily-circuit-quiet-room.

3 comments:

Bradley Christensen said...

I am really glad you posted this Stacey! I would love to have an opportunity to visit the Orfield Laboratories in Minneapolis and see if I am able to last 45 minutes or more. You see, the idea of sound intrigues me. I have had tinnitus for the past 12 years of so, resulting from severe ear related issues as a teenager. Throughout the day, symptoms don’t present themselves (thanks to the external noises of the world we live in), but at night, my ears ring, and at times, it sounds as if cicadas are chirping away. I attended a lecture of Dr. Blake Papsins at Sick Kids hospital, where he mentioned that our brain controls what we listen to at a particular moment, and that it is able to block out sounds if it wants, such as the low hum of data projector. Only when there is silence in the room is our attention brought to the projector.

So the comment made by Weber (2012) “when the ear is deprived of sound, it produces its own sounds” fascinated me highly. I wonder if this is entirely true, because as we read in the Jourdain book, sound is vibrating air molecules that is only heard once those molecules hit the ear. The vibrating air molecules, prior to entering, don’t make a sound. Hearing stems from the brain. So what Weber is therefore saying is that the eardrum, which a receptor, has become a manufacturer? I wonder if the sounds the ‘ear produces’ are the result of air molecules circulating inside the ears hollow spaces.

Anyway, I thought it was a great read, and I enjoyed how you equated it to music. I know that when the music stops at the end of a piece, it doesn’t seem like it has quite finished - it seems to last a bit longer. It was cool to see that scans have in fact been done that show brain activity after a phrase has ended. As the old saying goes, “the musical rests can speak louder than the music.”

Francois said...

Hello Stacy, I really appreciate that you wrote a post about silence, which is often regarded with less importance when compared with sound. Actually, I was surprised that the complete silence condition causes uncomfortable effects on humans. I have had the experience of working in a special studio called MMR (Multi Media Room) at McGill. The MMR is a floating box within an insulated building, and the only sounds heard in the room are those that are produced inside the room. I thought such experiences in an echoless chamber would be relaxing, but it is very surprising that one can only stand the situation for 45 minutes maximum! This might be the difference between the echoless and the noiseless.
I find Margulis’ categorization of silence is very interesting as well. Awareness of the five different functions of silence would enrich musical expressions while performing a musical piece.

Veronica V said...

Very interesting article!! I would like to visit Orfield Laboratories if I am ever in Minneapolis. I thought it was so interesting that you can hear your own lungs breathing, heartbeat beating, stomach digesting food, and blood rush to your head. I also thought it was interesting that the chamber causes people to feel claustrophobic considering that there is actually a lot of room in the space.
It is fascinating that "a complete absence of noise can lead to a heightened sense of smell or touch, but can also cause your hearing to become much more sensitive." I wonder if experiencing this would kind of give you a glimpse of how those who are impaired in a certain sense (like sight for example) feel.
I also wonder what it would be like to bring an instrument into the room and play it. It must be an extremely bizarre feeling to know that you are playing an instrument, but that no sound is coming out!
The article states that the longest time someone has spent in there is 45 minutes. I wonder what the average time is? Anyhow, it was really fascinating to read that people become dizzy and disorienting and feel like there is a tremendous amount of pressure on their head when really the pressure is being taken off your ears! It's so interesting to know that our brains recalibrate to our environment. Thanks for sharing Stacy!