HEARING LOSS

????????????????????????????????Noise-induced hearing loss

Globally approx. 16% of disabling hearing loss in adults is caused by occupational noise. What is noise, scientifically, noise is a sound that is often random or harmonically disorganized and lacks communicative content. Noise is sound that people do not like to listen though all sounds are not noise. Noise can interfere with your ability to work as it is causing stress and disturbing your concentration. Hazardous occupational noise or industrial noise encompasses both definitions along with two other key characteristics: duration and intensity, or amplitude.

Hearing loss is one of the most common of all occupational diseases and noise can cause chronic health problems. Hearing loss is due to exposure to noise in the workplace which is beyond the specified limit many times exposure remains longer time than specified. Hearing loss is not always easy to recognize, most workers do not realize they are going deaf until their hearing is permanently damaged. Industrial noise exposure can be controlled for minimal costs and without technical difficulty.

Temporary hearing loss can be due to short-time exposure to a noisy workplace, though, the longer you are exposed to the noise, the longer it takes for your hearing to return to normal. ?

Permanent hearing loss can never be repaired. It is important to look for signs of hearing loss due to shouting by co-workers, covering the ears, or leaving the workplace as it may indicate a noise problem. Exposure to occupational noise can increase accidents, increased stress, which can lead to heart, stomach, and nervous disorders, nervousness, sleeplessness, fatigue, etc and it also reduces job performance and increased absenteeism. Excessive exposure to noise may reduce job performance and may cause high rates of absenteeism.

Types of Noise

·????????Continuous Noise

·????????Intermittent Noise

·????????Impulsive Noise

·????????Tones in Noise

·????????Low-Frequency Noise

·????????Industrial Noise

·????????Road Traffic Noise

·????????Rail Traffic Noise

·????????Aircraft Noise

?

Measuring sound and noise

Sound is measured in amplitude, frequency, and time. All three are key factors to consider when addressing Noise-induced hearing loss. Amplitude describes the intensity of a sound and its units are decibels (dB). It can be measured as a change of sound pressure in the air or in the amount of energy produced by the vibrations and is perceived as the loudness of a sound. Frequency is to be measured in units of Hertz (Hz). It is the number of vibrations per second and is perceived as the pitch of a sound. The time of sound can be measured on scales of different magnitudes, but we consider duration as measured in seconds, minutes, or hours.

When evaluating the amplitude of a sound, there is often a letter ‘A’ appended to the measurement: ‘dBA’ or ‘dB(A)’. This is called A-weighting and means that low- and high-frequency sounds, which the human ear is less sensitive to, are being filtered out of the measurement. A-weighting is commonly used for measuring environmental and industrial noise. This is because some early research suggests that A-weighted sound measurements are often reasonable predictors of the damage risk to hearing from occupational noise.

There is another important reason why both amplitude and frequency are key factors to consider. A worker who has already suffered some degree of hearing loss, for example, may not be able to hear high frequencies in the 2,000 to 8,000 Hz range, which includes consonants such as s, h, or f or high-pitched beeping sounds such as alarms

Under such circumstances, it is vital to personalize their hearing protection to avoid overprotection and limit their sense of isolation or inability to hear key sounds in the workplace, which could potentially put them at risk.

The decibel scale is a?logarithmic?scale, a small increase in the decibel level can result in a big increase in the noise level. At any typical workplace, noise comes from different background sources, such as tools, plant machineries like compressors, diesel generating units, and the process of materials handling, etc. The noise at the workplace can be measured with help of a sound meter.

A safe level of noise basically depends on two things, one is the level or volume of the noise, and the second is how long you are exposed to the noise. The level of noise allowed by most countries' noise standards is generally 85-90 dB over an eight-hour workday, though some countries recommend that noise levels be even lower than this. To protect the health of workers who are exposed to high noise levels are to be provided with?ear protection and they are to be rotated. ?

Workplace noise can be controlled at the source, with the use of barriers and ear protection.

The best method of prevention is to eliminate the hazard and controlling noise at its source is the best method and it can be cheaper than other methods of noise control. New machines such as presses, drills, etc. are to be purchased with minimum acceptable noise standards. Noise control at the source can also be?engineered by adjusting parts or a whole machine that reduces noise. To reduce the noise level in the industry regular maintenance, lubrication, and?replacement?of worn or defective parts are to be done.

Methods to reduce noise include:

• Reducing impact between machine parts.
• Reducing speeds between forward and reverse movements.
• Replacing metal parts with plastic parts.
• Enclosing particularly noisy machine parts.
• Providing mufflers to air outlets of pneumatic valves.
• Replacing the noisy pump in hydraulic systems.
• Changing to quieter types of fans or providing mufflers in the ducts of ventilation systems.
• Providing mufflers for electric motors.
• Providing mufflers at the inlet of air compressors.???????????????
• Replace some noisy machinery.
• Reduce the drop of goods from a height to collect in bins and boxes.
• Increase the rigidity of vessels having an impact on goods.
• Reduce the speed of conveyor systems.
• Use belt conveyors in place of the roller type.

When it is not possible to control the noise at the source, it may be necessary to?enclose?the machine, and place?sound-reducing barriers between the source and the worker.

The followings are ways to control noise with barriers:

• An enclosure should not touch any part of the machine.
• Opening in the enclosure should be minimized.
• Access doors and openings should be fitted with sound-absorbent materials like rubber gaskets.
• Exhausts and air vents in the open area must be silenced and directed away from operators.
• The source of the noise should be separated from other work areas.
• The noise should be away from work areas with a sound-insulating or reflecting barrier.
• The sound-absorbent materials should be used, if possible, on walls, floors, and ceilings.

To control noise, workers use ear protection as a hearing protection device. There are two types of ear protection, one is earplugs, and other is earmuffs which are designed to prevent excessive noise from reaching the inner ear. Earplugs are in a variety of materials, including rubber, plastic, or any material that will fit tightly in the ear.

Earplugs are the least desirable type of hearing protection because they do not provide very effective protection against noise, and they can cause ear infections if the dirty plug is kept in the ear long time. Earmuffs are more protective compared to earplugs if they are used correctly. ?

If ear protection is provided instead of controlling the noise at the source by industries management than then management is entrusting the responsibility to the worker.

?

Methods of noise control

1. The best method of noise control is at the source. This can be done by the manufacturer, through engineering changes on the source itself, ?through regular maintenance, lubrication, and replacement of parts, or by changing the way materials are handled.
2. By enclosing the source of noise, it can be controlled. Provide a barrier at the source of the noise, place sound-reducing barriers between the worker and the source or increase the distance between the worker and the source.
3. To reduce noise exposure, workers are provided with ear protection and earmuffs are a better choice than earplugs.
4. The workers are to be trained in the proper use of, and the importance of wearing, their ear protectors.

1.???Provide a silencer on the machine to reduce noise.

???

??2. Noise-insulated air compressors. The purpose is to reduce noise by covering the noise under the hood. The hood is made with a soft absorbent lining.

?The role of the health and safety representative is to work proactively acting?before?there are health or hearing problems to eliminate or control occupational noise exposure.?

Role of Safety representative:

1. To watch for early signs indicating hearing loss. Train co-workers such that they also look for warning signs to use heat protection.
2. To measure and monitor precise levels of noise and the sources of noise in the workplace.
3. Try to obtain any results of the noise monitoring and compare the results with your acceptable noise standards.
4. Conduct a simple method for assessing noise exposure, if one cannot speak in a normal tone and must shout to communicate, then the noise level at the workplace is too high and should be reduced.
5. To engineer noise reduction at the source as it is cheaper than buying ear protectors for everyone and providing barriers.
6. To rotate shift duty of workers after more than four hours of continuous work at noise level.
7. To ensure that workers who wear ear protectors do not get exposed to noise levels of 95 dB or more for more than four hours per http
8. s://www.dhirubhai.net/redir/general-malware-page?url=day%2eTo train workers in the proper use
9. of, and the importance of wearing, their ear protectors. To clearly mark the area of high noise level to wear the ear protectors by using symbols showing the need for ear protectors. ?Try to est
10. ablish a non-verbal way of communication for these areas. Conduct a periodic audit or observation of the workplace w
11. here workers face problems with noise in their work areas.There must be regular hearing tests provided for workers exposed to excessive noise.

Noise at the workplace can be controlled by a variety of methods, the most effective of which is controlling noise at the source; the least acceptable method is relying on ear protection. As per statutory norms, the allowable noise level of 85-90 dB over an eight-hour workday though it is better to reduce noise even further, whenever possible.

Hearing loss is a significant risk to both workers and businesses.?The latest regulatory and technological developments are also key to ensuring that a hearing loss prevention program is up to the latest standards and takes advantage of the most advanced tools. Technology will also provide answers to improved hearing protection.

Noise is a hazardous industrial pollutant causing severe hearing loss in workers of every country in the world. The workers in industries like mining, construction, printing, sawmills, crushers, etc are at risk. Workers are exposed to high levels of noise throughout their lifetime of work, but there are very few Noise-induced hearing loss studies in India to show its prevalence.

There should be education and training programs to create awareness among workers about the harmful effects of noise on hearing and other health hazards.

Research studies are needed to know the exact prevalence of Noise-induced hearing loss among various industries in India. A national program should be established considering the amount of damage the ?Noise-induced hearing loss ?causes to the quality of life of workers.