Noise can cause various health problems in general, such as hearing loss, other physiological disorders and psychological disorders. Physiological disorders may include increased blood pressure, pulse rate acceleration, increased basal metabolism, vasoconstriction of blood vessels, decrease in intestinal peristalsis as well as increased muscle tension. The physiological effects caused by increased stimulation of the autonomic nervous system. This situation is actually the body's defense mechanism against the danger that occurs spontaneously. Psychological disorders can be additional stress if the sound is undesirable and disturbing, giving rise to unpleasant feelings and exhausting. To the above can cause sleep disturbance, emotional, communication disorders and impaired concentration which indirectly could jeopardize safety.
Types of Hearing Loss due to Noise
Hearing loss due to noise is a type of sensorineural hearing loss, which initially did not realize, because not interfere with everyday conversation. The nature of the interference is sensorineural deafness cochlear type, and generally occur on both ears.
The basis for determining a hearing loss due to noise is hearing threshold shift, namely the difference between hearing threshold in the previous measurement with hearing threshold after noise exposure (the unit used is the decibel (dB)). The hearing threshold shift can be temporary or permanent.
Hearing loss due to noise generally occurs in industrial populations with 4 main factors that cause harm to the hearing, among others:
Intensity / hard-weak sound / noise
Frequency / high-low sound / noise
Prolonged exposure to noise working day
Cumulative noise exposure (length of service)
Hearing loss due to noise and diseases caused by vibrations that occur in factory workers caused by the use of mechanical devices that may cause mechanical noise and vibration.
Many jobs in industries that use mechanical devices and some of the mechanical force is distributed to the worker's body, in the form of mechanical vibrations. Unlike the air vibrations that influence the acoustic, mechanical vibration resulted in the emergence of resonance organs, so that the mechanical effect.
The mechanical effects cause the tissue cells can be damaged or disturbed metabolism. In this case the mechanical effects can occur in the tissue, and nerve stimulation of nerve receptors in the tissue.
Examples of sources of noise pollution and vibration obtained at the workplace is: rumble factory machinery, turbine, cutting tools and so forth.
Kinds of hearing loss due to noise is as follows:
1. Acoustic Trauma
In the acoustic trauma, ear organic damage occurs as a result of the sound energy is very large. This effect occurs as a result of its path physiologic ability ear resulting in an impaired ability to transmit vibrations corti organ. Damage may be rupture of the eardrum, ossicular damage or direct damage corti organ. Patients are usually not difficult to determine the time of the trauma which causes hearing loss.
2. Noise-Induced Temporary Threshold Shift.
In this situation occurs increase the value of the auditory threshold while after exposure to noise and is reversible. To avoid auditory fatigue, the hearing threshold in the measure back 2 minutes after exposure to sound. Factors that affect shift the hearing threshold is the sound level, the duration of exposure, frequency tested, sound spectrum and patterns of exposure to temporal as well as other factors such as age, gender, health status, medication (some medication may be ototoxic causing permanent damage) and state of hearing before exposure.
3. Noise-Induced Permanent Threshold Shift.
Data supporting the existence of permanent hearing threshold shift value in getting the reports of workers in the industry because it is not possible to experiment on humans. From the observation data in industrial environments, the factors that affect the auditory response to noise in the workplace is the sound pressure in the air, the total duration of exposure, noise spectrum, transmission apparatus to the ear, as well as individual susceptibility to hearing loss due to noise.
While the mechanical vibrations can be distinguished on whole body vibration and vibration of the tool motion (vibration-hand tool). Each work differently to cause disease.
1. Vibration entire body
Vibration in the entire body mainly occurs in a conveyance, for example truck, equipment transport on industrial, agricultural tractors and so on. Strong vibrations can cause tremendous pain and can also cause eye irritation.
2. Vibration in the arm
The works that use vibrating tools on an ongoing basis, such as in mining drilling, grinding in a factory or power saws in forestry work may cause interference or abnormality due to mechanical vibration on the arm. Such defects include abnormalities in blood circulation and innervation, as well as damage to the joints and bones. Symptoms of abnormalities in the circulatory and innervation starting with pale and stiffness in the fingertips that occur repeatedly and second-hand bicycles extends asymmetrically.
