Noise-Induced Hearing Loss

Noise-induced hearing loss (NIHL) is one of the biggest occupational health problems facing us today, and whilst damage can be irreversible, it is preventable.

NIHL is a gradual process and when hearing damage occurs, it can be too late to treat and return a person's full hearing. It occurs mainly in men, and the highest rates of NIHL occur in energy and extraction, construction and manufacturing industries.

We know the dangers, but the first step is understanding how NIHL happens, and then exploring how it can be protected against in your workplace.

The ear is made up of three sections - the outer, the middle and the inner. These three areas work together to enable us to hear and contribute to our ability to balance.

Sound waves enter the outer ear and travel down the ear canal to the ear drum, causing it to vibrate.

The middle ear is an air-filled space that links the outer ear with the inner ear. Three tiny bones extend from the eardrum to the cochlea. These three bones collect the sound waves and pass them through to the inner ear.

Healthy Cochlea

The cochlea is the part of the ear that enables us to hear. The cochlea is a fluid-filled chamber that looks like a snail shell lined with tiny hair cells. When the sound waves reach the cochlea, the hair cells change the vibrations into electrical signals. These signals are passed to the brain, telling you that you are hearing a sound and what the frequency and volume of the sound is.

Using ear plugs will ensure:

• Low noise exposure
• Normal cochlea
• Receptors intact

Damaged Cochlea

Exposure to regular and long-lasting noise damages the sensitive hair cells in the cochlea, which can result in permanent noise-induced hearing loss. It can also result in tinnitus, a buzzing or ringing noise that originates in the person's ear. These tiny hair cells cannot be repaired or replaced, so when they’re damaged or destroyed, it's permanent.

Without ear plugs can cause:

• High noise exposure
• Damaged cochlea
• Receptors destroyed

Hearing loss related to noise exposure is called sensorineural hearing loss. This reduces your ability to hear quiet sounds and affects the quality of the sound that you hear, meaning that conversational speech, interactions and recognising warning signals can become more difficult.

Short exposure to excessive noise produces varying degrees of inner ear damage that is initially reversible but can become permanent through regular exposure. Recovery time can be anything from minutes to days. This is known as an acute or temporary threshold shift.

Noise-induced hearing loss is a major occupational health problem, and the second most common reason for occupational health-related employers' liability insurance claims.

• Noise induced hearing loss (NIHL) is one of the biggest occupational health problems facing us today
• Whilst NIHL is permanent and irreversible, it's also preventable. NIHL is a gradual process and when hearing damage occurs it is too late
• NIHL is a long latency disease that is difficult to estimate accurately
• NIHL disease occurs mainly in men. Highest rates of NIHL occur in energy and extraction, construction and manufacturing industries

You can help reduce exposure to high levels of noise by organising the workplace, creating hearing protection zones, and investing in high quality hearing protection.

View our comprehensive range of hearing protection products including earplugs, ear defenders and communication solutions.