According to a 2009 study into the effects of hearing loss, often caused by exposure to excessive noise levels, and how the body copes with a reduced sensory function, the brains of adult animals with a hearing deficiency appeared to re-route the sense of touch into the brain area that processes hearing.

The compensatory behaviour, known as cross-modal plasticity, seems to reorganise connections between the four main brain lobes as a response to the loss of one of the senses, e.g. an impaired auditory function as a result of hearing damage, which leads to the affected sense being replaced with one still intact.

A long history of reported evidence has contributed to an ongoing debate surrounding the suggestion over whether those individuals who lose one sense, such as hearing, find that another one of the senses becomes intensified.

The scientific thought behind the concept cross-modal plasticity aims to prove by using MRI scanning techniques that a rerouting of electrical stimulus occurs by crossover and interaction between the two separate, specific sense areas of the brain.

Results of the research appear to show that the cross-over can cause problems when there is only a partial hearing loss. Interpretation of residual hearing stimuli, i.e. background noise, can cause confusion in the interpretation of the sense data.

Essentially, the study indicated that hearing deficits in adult animals resulted in a conversion of their brain’s sound processing centres to respond to another sensory modality, making the interpretation of residual hearing even more difficult.

The research seems to suggest that even a mild noise induced hearing loss in adult humans could have serious and perhaps progressive consequences. The implication being that partial hearing loss sufferers may actually be significantly worse off than those with total industrial deafness because the potential to reroute sense stimuli is compromised by still receiving a reduced auditory signal.

Often, a slow deterioration in hearing can occur over a long period of time, which unfortunately means that the gradual reduction in the ability to hear clearly may go undetected whilst still working in environments exposed to an excessive level of background noise.

It is estimated that there may be as many as a quarter of a million people worldwide who are unaware that they are suffering some form of hearing loss as a result of their working environment.