NOISE AND ITS EFFECT TO HUMAN

The sound is a pressure disturbance that it can be detected by the ear or mechanical compression or longitudinal waves that propagate through a medium, medium or intermediary agent can be a liquid, solid, gas. Most of the noise is a combination of various signals, but purely theoretically sound may be explained by the speed of oscillation or frequency measured in Hertz (Hz) and the amplitude or loudness of a sound measurements in decibels (dB). Humans hear when a sound wave, the vibration of air or other medium, to human ear druk. Limit the frequency of sound that can be heard by human ears roughly from 20 Hz to 20 kHz. The sound below at frequency 20 Hz called infrasonic, at other hand the sound over at the frequency 20 kHz called ultrasonic. There also the sound frequency have a general amplitude with variations in the curves of response.

Noise is sound or voice undesirable and detrimental to health and environmental comfort expressed in decibels (dB). Noise can also be defined as unwelcome noise, disturbing sound or sound annoying. Based on the Decree, the noise is unwanted sound that comes from the equipment, production process at a certain level can cause health problems and hearing.

Sound raises the noise caused by vibrating sound source. Vibration noise source is disturbing the balance of the surrounding air molecules so that the air molecules vibrating. Vibrations caused a wave source of mechanical energy propagation in the medium conditioned by propagation longitudinal pattern. Wave sound propagation in air is known as sound or noise while in the context of space and time so that it may cause interference comfort and health

The source of noise is the sound sources whose presence is considered intrusive hearing from both mobile and fixed sources. Generally, the source of the noise can be derived from industrial activities, trade, construction, power generation equipment, transporters and household activities. In industry, the source of the noise can be classified into three types, namely

1. machine, the noise generated by the activity of the machine.
2. Vibration,due to the noise generated by the vibration caused due to friction, impact or imbalances movement of the  machine. Occur on gears, flywheel, torque rod, piston, fan, bearings, and others.
3. The movement of air, gases and liquids. The noise is caused due to the movement of air, gases and liquids in the activities of the working process industry, for example in gas liquids pipelines, outlet pipe, exhaust, jet, flare boom, and others.

Noise is sound or noise that is disturbing. Noise can cause various disorders such as physiological disorders, psychological disorders, communication disorders and deafness. There is classification of the disturbances in the form of auditory disorders, such as disorders of the auditory and non-auditory disorders as communication disorders, safety hazards, the decline in performance of work, stress and fatigue. More detailed noise effect on the health of workers will be described as follows:

In general, high-pitched noise is very annoying, especially when intermittent or the arrival of a sudden. Disorders can include increased blood pressure, increased pulse, constricting peripheral blood vessels, especially in the hands and feet, and can cause pale and sensory issues. Noisy with high intensity can cause dizziness / headache. This is due to noisy situations can stimulate the vestibular receptors in the inner ear that will cause effect to dizziness / vertigo. Nausea, insomnia and shortness of breath because noise stimulation to the nervous system, balance organs, endocrine, blood pressure, digestive system and electrolyte balance. Psychological disorders may include discomfort, lack of concentration, insomnia, and irritable. If the noise is received in a long time, it can cause psychosomatic diseases such as gastritis, heart disease, stress, fatigue and others.

Communication disorders usually caused masking effect (sound cover less clear hearing) or disturbance sound clarity. Communication talks must be done by shouting. This disorder causes the disruption of work, to the possibility of error because they do not hear the signal or alarm. These disruption of communication are not directly endanger the safety of any person. Noisy very high can lead to the impression of walking in space or drift, which can cause physiological disorders such as dizziness (vertigo) or nausea.

The primary effect of noise on health is damage to the sense of hearing, which causes progressive deafness and this effect has been known and generally accepted from a bygone era. At first, the effect of noise on hearing is temporary and pemuliahan occur quickly after the work in a noisy area is stopped. But when work is constantly in a noisy area, there will be deaf settled and cannot be normal again, usually starts at a frequency of 4000 Hz and then widening to frequency vicinity and eventually the frequency normally used for conversation.