Noise is one of the most common physical hazards present at work. The exposure limits to prevent noise induced hearing loss (NIHL) are an 8-hour average exposure of 85dB(A) or a peak noise exposure of 140dB. If your work shift is longer than 8 hours, then the amount of noise you can be exposed to before you get NIHL will change. If you don’t know the level of noise to which your workers are exposed or you issue hearing protection, then you likely require a noise survey to meet legislative requirements. The goal of noise monitoring is twofold. Firstly, it allows determination of the noise levels to which workers are exposed for the purpose of implementing control strategies (noise dampening, control booths, hearing protection, etc) and secondly, it allows evaluation of the class of hearing protection required to prevent NIHL. Did you know that removing your hearing protection in a noisy area, even to have a short conversation, can put you at risk. Noise monitoring allows us to determine how long you can be exposed to the noise levels at a workplace before you are at risk of NIHL.
We hear this all the time and although it can provide an indication of noise levels, it isn’t sufficient to determine a workers personal exposure. The reason is, that there are two types of noise measurements: Spot Measurements and Dosimetry measurements. Spot measurements are great for measuring the noise output from a process or a machine, but workers are highly mobile with their noise exposure varying drastically as they move around a workplace. Dosimetry measurements involve the worker wearing a small noise meter on their shoulder for the majority of their work shift. This allows us to capture a true representation of the workers’ average and peak exposures, and is the method required by WorkSafe NZ for comparing workers’ noise exposure against the workplace exposure limits.