Friday, February 15, 2013

The Subjectivity of Noise

     There is noise all around us.  City streets filled with roaring buses and people on their cell phones.  There is so much noise around us that we tend to ignore it.  Ignoring the noise does not make it go away. Noise pollution is often the last thing to be considered when designing a building.  Noise is considered to be any unwanted sound.  This definition is a bit subjective since everyone has different ideas of what can be categorized as unwanted sound.  Someone may say the sound of their neighbor banging away on drums at midnight is noise, while the drummer perceives it as music.  While the threshold of what delegates wanted from unwanted sound is blurry, there are many things that are considered noise in which society is in agreement.  Below is an amusing picture that helps to illustrate the subjectivity of noise.


The sign above states that "unnecessary noise is prohibited," but what constitutes unnecessary noise? This sign does not make sense because what is considered noise to someone may be pleasing to another.  And is there such a thing as necessary noise?  If noise is defined as unwanted sound then necessary noise would imply that it is in fact wanted, therefore contradicting the definition.  So all this sign does is produce a paradox.


     Noise pollution is a growing concern in the world today and before we can tackle this issue, we need to first define the types of noise that are polluting the environment. To do this we must look at the noise sources that society is in agreement. Such sources can include traffic, trains, rooftop HVAC units, and loud machinery. Noise sources are location based so in a school, noise can be the classroom next door being too loud. This is a noise source for students in the other class. They will have trouble paying attention and studying when noise from the class next door is being transmitted into their learning environment.

   The following LINK will show an article about rising noise levels in New York City.  The noise level are getting so bad that hearing loss is being caused over extended periods of time.  Exposure to high decibel levels for extended periods will cause hearing damage, and when the people of New York are experiencing 70dB and up for more than 8 hours a day it begins to take its toll. 

     Future blog posts will dive deeper into these various sources of noise as well as common methods of treatment.  For now, understand that the best way to treat noise is at the source.  Engineering said device to not emit strong noise levels is the best solution.  However, most of the time it's very expensive and time consuming to go this route.  Click HERE to see some information on types of noise and some common ways to treat them.  This will help to further explain what I have just talked about and also serve as a transition into future topics. 

-Jon Owens
Audio Engineer/Sound Designer/Acoustic-AV Consultant
www.jon-owens.com