Sound is the physical agent that impressed by the sense of hearing. Sound is produced by vibrations of the body and is transmitted through a material medium in the form of wave motion. The human ear is able to perceive sounds between 20 and 20,000 hertz, or vibrations per second, with maximum sensitivity between 2,000 and 5,000 hertz.
Noise is an inarticulate sound, usually unpleasant and unwanted. For its measurement using a logarithmic scale because the sensitivity of the human ear has a sound intensity variations is approximately logarithmic scale, not linear. The decibel (dB) is the unit used in acoustics on with 20 micropascals as threshold pressure (P0). Its expression is 20 log P/P0.
Examples of noise levels are:
- Birds chirping: 10 dB.
- Library: 30 dB.
- Residential areas: 40 dB.
- Normal conversation: 50 dB.
- Alarm clock: 80 dB.
- car horn: 90 dB
- Nightclub: 100 dB.
- Jackhammer: 110 dB.
- Take-off plane (60 m): 120 dB
- Thunder
130 dB - Threshold of pain: 140 dB.
- irreversible hearing loss: 180 dB. Etymologically
noise comes from the Latin term rugitus (roaring). The role of noise perception by animals, including humans, is the alarm. In contrast, the sound is not loud is communication. All animals react to noise on the run, hiding or fighting aggressively for their cause. The man is no exception. It instinctively give the same reactions but often modulated or inhibited by the will, which increases the stress level.
noise comes from the Latin term rugitus (roaring). The role of noise perception by animals, including humans, is the alarm. In contrast, the sound is not loud is communication. All animals react to noise on the run, hiding or fighting aggressively for their cause. The man is no exception. It instinctively give the same reactions but often modulated or inhibited by the will, which increases the stress level.
The noise affects the quality of life and can cause adverse effects to our health. Therefore, the World Health Organization (WHO) sets the acceptable limit 65 dB during the day and 55 dB at night. Studies by the World Health Organization, ambient noise can cause: permanent reduction in hearing, and sleep disorders behavior, mental fatigue, attention difficulties, antisocial behavior ...
We measured the noise with a calibrated sound level meter with 20 micropascals as pressure threshold, in various locations in Seville and the values \u200b\u200bobtained are beyond the limits established by the Municipal Ordinance noise.
Several Associations have reported to the City for not having produced the noise maps as required by the law and for not having renewed the declaration of areas affected.
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