Persistent noise at work could more than double the risk of heart disease, a study by researchers at the University of British Columbia suggests. A further report from the World Health Organisation (WHO) identified a chronic 50dB night-time level (i.e., a persistent level at 50dB) as being sufficient to cause strain on the cardiovascular system. In many countries, levels of 80dB are considered acceptable, which leads us to believe that current occupational noise levels could be a more serious issue than previously thought.  

Current health and safety legislation places a duty on employers to ensure that workers’ hearing is protected from excessive noise at their workplace, which could cause them to lose their hearing and/or to suffer from tinnitus.  

Before even thinking of reducing noise to much lower levels, it is essential that companies begin by implementing a hearing conservation programme, as this will form the foundations of any future noise-reduction efforts. This is a process that involves three main parts, all of which must be effectively implemented for the system to work: health surveillance, risk assessment and noise control. 

Health Surveillance 

Finding out who among their workforce is at heightened risk will require employers to carry out health surveillance for noise-induced hearing loss, which means conducting hearing tests. Questionnaires and interviews will form part of a comprehensive testing programme, together with audiometry. The results of audiometric testing should trigger specific assessments, which, in turn, should guide the process of control and the use of Personal Protective Equipment (PPE).  

Risk Assessment 

Assessing the risk of injury to an employee from noise involves working out how much noise they are being exposed to. 

Noise Control 

Noise should always be reduced so far as is reasonably practicable, irrespective of the legal thresholds at which certain action should be taken, or whether or not hearing protection is used.  

There are some actions that employers can adopt, which can yield significant results. 

• Absorption – Absorption has a part to play in a control programme. This should only be used on the advice of a noise-control expert. 
• Enclosures – For some machinery, enclosures may be a suitable solution. These should be specified and installed under professional guidance. 
• Air noise – Employers should ensure that leaks are controlled, low-noise nozzles on blowing lines are being used, and exhaust filters are all working properly.  
• Engineering and maintenance – Well-maintained machinery makes less noise, so reducing the inherent noise a machine or process emits requires an engineering approach. This can often be enough to avoid the use of enclosures and absorption methods. 

These actions should be followed until an air-tight system which stops people suffering from hearing problems due to their work is achieved.