Canadian Centre for Occupational Health and Safety (Extracts)
What are non-auditory effects? Hearing loss from long term exposure to noise has been recognized as a hazard for a long time. However, what the non-auditory effects of noise are is still not certain. In general, the suspected effects include cardiovascular function (hypertension, changes to blood pressure and/or heart rate), and changes in breathing, annoyance, sleeping problems, physical health and mental health. This wide range of effects has led researchers to believe that noise has the ability to act as a general, non-specific stressor. It is very difficult to pin point what the effects of noise are versus the effects of other general stressors.
In the workplace, non-auditory effects of noise include problems with oral communications. It has also been shown that absenteeism appears to be higher among workers in noisy industries. It has not been concluded whether this is from psychological aversion to noise or from physiological consequences of noise stress.
What types of non-auditory effects are there? Non-auditory effects can be divided into two categories - physiological effects and performance effects.
What are some examples of physiological effects? The physiological effects can be temporary or permanent.
Examples of temporary physiological effects are:
the startling response to loud noise, where muscles burst into activities, generally, with the intention to protect
the muscle tension response, where muscles tend to contract in the presence of loud noise
the respiratory reflexes, where the respiratory rhythm tends to change when noise is present
changes in the heart beat pattern
changes in the diameter of the blood vessels, particularly in the skin
All those effects are similar to the response of the body to other stressors.