Noise-Induced Hearing Loss (NIHL) is one of the most common health and safety problems in New Zealand, especially as we spend more time around loud machinery, music, and recreational noise. According to the World Health Organisation (WHO), workplace noise is responsible for approximately 16% of adult hearing loss worldwide (Zhou et al., 2020).

The good news is that protecting your hearing is simple and it does not mean giving up the things you enjoy!

Can loud noise damage my hearing?

NIHL happens due to the combination of how loud the noise is, and how long you are exposed to it for. The louder the sound, the shorter the amount of time it takes for hearing loss to occur.

A good rule of thumb is that if you need to raise your voice to speak to someone standing a metre away, the noise is likely loud enough to damage your hearing, even if your ears seem “fine” afterwards.

Prolonged exposure to loud noise can lead to permanent hearing loss, which, in turn, can lead to other conditions such as tinnitus (ringing in the ears), social isolation, cognitive decline, affected sleep, and chronic stress.

The 5 classes of hearing protection

Hearing protection in New Zealand is tested to the standard AS/NZS 1270:2002 Acoustics: Hearing protectors. Earmuffs and earplugs are rated from Class 1 to 5. The class tells you how much noise they’re designed to keep your ears safe around, so the louder your environment, the higher the class you need.

• Class 1 protects environments up to 90 decibels (dB).
• Class 2 is suitable for 90–100dB.
• Class 3 is recommended for 95–100dB.
• Class 4 provides protection for 100–105dB.
• Class 5 is intended for noise levels of 105–110dB.

It is also important to choose a style of hearing protection that works for you. It needs to be comfortable, fit consistently, and fit well with any other Personal Protective Equipment (PPE) you might need to be wearing. You can find both earmuffs and earplugs in all classes up to Class 5. When choosing the right style for your work, make sure to check the fit. Not only are you less likely to wear hearing protection consistently if it’s uncomfortable, but if your earmuffs don’t seal properly, or earplugs aren’t inserted correctly, they won’t protect your hearing the way they should.