Noise is one of the most common hazards at work, yet its effects are often ignored, because the damage builds up slowly and without pain. By the time someone notices that their hearing has changed, the damage is usually permanent.

Noise-induced hearing loss is one of the most widespread occupational diseases. It affects workers in construction, manufacturing, engineering and many other sectors.

This course explains how noise harms hearing, what the law requires, and how noise risk is assessed and controlled.

By the end of this module, you will be able to:

• Explain what noise is, and why it is a workplace hazard.
• Describe how noise is measured in decibels.
• Name the law that controls noise at work.
• Describe the main duties of employers and employees.
• Recognise the simple signs that noise may be a problem.

Noise is unwanted sound. Sound is created by vibrations that travel through the air as pressure waves, and reach our ears.

The more energy there is in those waves, the louder the sound, and the greater its potential to damage hearing. A sound does not have to be unpleasant to be harmful. Loud music can damage hearing in exactly the same way as a loud machine.

The loudness of sound is measured in decibels, written dB.

The decibel scale is logarithmic, not like an ordinary ruler. An increase of just 3 dB means the sound energy has doubled. So a small rise in the number on a meter means a large rise in the risk to hearing.

This is why a machine that seems only a little louder than another can be far more harmful over a working day.

Harmful noise is common wherever there is:

• Powered machinery, tools and engines.
• Impact work, such as hammering, riveting and pressing.
• Grinding, cutting and drilling.
• Compressed air and pneumatic tools.
• Loud alarms and warning signals.

It is found in factories, workshops, construction sites, quarries, farms, bars and nightclubs, and many other workplaces.

In Ireland, noise at work is controlled by Part 5, Chapter 1 of the Safety, Health and Welfare at Work (General Application) Regulations 2007, called Control of Noise at Work.

These regulations put the European Physical Agents (Noise) Directive into Irish law. They sit under the Safety, Health and Welfare at Work Act 2005, which places a general duty on every employer to protect the safety, health and welfare of their employees.

The noise regulations require employers to:

• Assess the risks from noise, and identify who is exposed.
• Eliminate noise at source, or reduce it to a minimum.
• Provide suitable hearing protection where noise cannot be reduced enough.
• Mark areas where hearing protection must be worn.
• Provide health surveillance, including hearing checks, for workers at risk.
• Give workers information, instruction and training.

Each of these duties is explained in detail later in the course.

In Ireland, the Health and Safety Authority, or HSA, enforces the noise regulations. HSA inspectors can visit workplaces, ask for noise assessments and records, and check that controls are working.

Where they find problems, inspectors can give advice, serve improvement or prohibition notices, and in serious cases prosecute the employer.

Employers must protect workers from the risks of noise, following the duties set out in the regulations.

Employees have duties too. You must:

• Use the noise controls and hearing protection provided, as you have been trained.
• Look after your hearing protection, and report any damage.
• Attend hearing checks when asked.
• Report any problems with noise controls, and any changes in your hearing.

You do not need a meter to suspect a noise problem. As a simple guide, noise is likely to be a risk if:

• People have to shout to be heard by someone about 2 metres away.
• The noise is intrusive for most of the working day.
• Workers use noisy powered tools or machinery.
• There are loud impacts or explosive sounds, such as hammering or cartridge-operated tools.

Your own body can also warn you that noise is too high. Warning signs include:

• Ringing or buzzing in the ears after work.
• Hearing that sounds dull or muffled at the end of a shift.
• Needing to turn up the radio or television more than before.
• Finding it harder to follow conversations in a noisy place.

If you notice any of these signs, report them to your supervisor. They show that your hearing is being harmed.