Friday, February 1, 2008


Attended a lecture on Noise tonight. Though there promised to be indications for health, there were but a few. Noise is being considered like the new chaos theory and there are both helpful and harmful elements of it when considered scientifically. However at the level of the human organism, we are not evolved to live an environment that is as noisy as ours. In the pre-historic environment in which early hominids lived, the world was a much quieter place. Loud, sudden and jarring noises were more likely to be cataclysmic events and often life threatening, so these early hominids had a strong adrenal response which allowed them to fight or flee. Though we are exposed to loud and sudden sounds on a much more regular basis, we have not evolved beyond the adrenal response of our ancestors.

In addition to this panic response, which may be sub clinical or undetected, noise interferes with our sleep and affects our hearing. A JAMA article estimated that 15% of American teens have levels of hearing loss comparable to the elderly - the article may or may not have attributed these levels of hearing loss to the use of headphones attached to devises capable to high decibel levels, but the speaker certainly did. He advised the responsible and careful use of such devises, because hearing loss can be insidious, resulting in a positive feedback loop where the listener continues to raise the volume on their [brand redacted] portable listening devises as their hearing diminishes, which only results in further damage.

The environmental impact of noise pollution also cannot be overestimated. Studies have shown that certain songbirds and humpback whales have had to raise the volume of their songs in noisy environments. The effect of this on mating amongst these animals is undetermined. The speaker also implicated low frequency sonar in the deaths of several beaked whales which have washed up dead, bleeding from the ears, a few hours after sonar experiments.

Aside from these negative impacts of noise, the way that noise may amplify an intentional signal was also discussed. Scientists are experimenting with this utilization of noise in the field of nanotechnology. Examples were given of how some crayfish and crickets use noise to amplify the vibrations caused by their natural predators, how the paddle fish of the midwest can only detect zooplankton within an ideal noise range and how neurons that act like switches may benefit from some level of noise. The more relatable example may be the way that someone hard of hearing may actually be able to hear a bit better in a slightly noisy room. And the author sited how a bit of background noise actually helped him concentrate when studying and taking examinations.