The sound of a distant train, the soft murmur of a sleeping child, the gentle clatter of a wind chime, early morning melodies of song birds, a baby giggling, doves cooing. Sounds are ubiquitous. They wake us in the morning, they alert us in times of trouble, can trigger memories and be a source of enjoyment. Yet in today’s world they can often be a major source of annoyance.
For example: that blasting sound coming from your child’s boom box, the 6am startup of the lawn mower, the constant roar of traffic on a busy street, late night barking dogs, the dripping of a faucet in the middle of the night – those are all noise. Derived from the Latin word “nausea”, meaning sickness, the word “noise” is defined as “unwanted sound”.
The problem with noise is that it is not only unwanted, but can adversely effect physical as well as mental health. Excessive noise can induce hearing loss, high blood pressure, sleep loss, cardiovascular problems and headaches. The psychological impact of noise can be annoyance, stress, nervousness, tenseness, despondency, aggression and a hindrance to communication. Occupational noise exposure claims more victims each year than any other occupational injury.
The strength or intensity of sound is measured in decibels (dB). The decibel scale is based in powers of 10. The sound intensity multiplies by 10 with every 10 decibel increase. For example, while 10 decibels is 10 times more intense than one decibel, 20 decibels is 100 times more intense (10 x 10, not 10 + 10) and 30 decibels is 1000 times more intense (10 x 10 x 10) than one decibel. We hit our threshold for pain between 120 and 140 dB. Sound begins to damage our hearing at a much lower level — somewhere between 80 dB and 85 dB if the exposure is long enough. The following tables list some fairly common noises and the decibel level:
- (dB) level 0 – barley audible
- 30 – a whisper in church
- 60 – normal conversation
- 90 – a running lawn mower
- 100 – a chain saw
- 115 – a rock concert
- 140 – a jet engine
- 180 – lift off!
Noise can be a key factor in determining the quality of our environment. Noise effects us at home, at work and at play. The State of California recognized this relationship between noise and quality of life and in 1976 added the Noise Element to the list of required elements of the General Plan.
The purpose of the Noise Element is to retain and protect the quality of life by first identifying sources of noise. Then implement measures and possible solutions to prevent, reduce and control noise.
California State Government Code section 65302(f) states “ The general plan shall include a noise element which shall identify and appraise noise problems in the community.” Using guidelines provided by the Office of Noise Control in the State Department of Health Services the element must analyze noise levels from the following sources;
- highways and freeways
- primary arterials and major local streets
- passenger and freight trains
- airport operations
- local industrial plants
- other ground source identified by the city
As development continues it is imperative that the Noise Element is tightly entwined with the Land Use, Housing and Circulation Elements. If these elements are not carefully planned the results can be intrusive noise which could degrade the quality of life for residents and visitors.