Sound affects us in many different ways

When mentioning sound and health in the same sentence most people think about hearing loss, but such damage is mainly caused by higher sound pressure levels than is common in most indoor environments. Much research has been done on health effects on exterior noise, such as traffic noise, and often the resulting conclusions have been extrapolated to indoor environments. The acoustic environment at e g working places or in schools have shown to be more complex.

There are many unwanted effects of sound that occur at relatively low sound pressure levels. Among the most important are:

• Loud acoustic environment
• Overhearing other peoples' speech
• Poor acoustic privacy
• Poor working or study environment

A loud acoustic environment can be excessively annoying, and can decrease the feeling of well-being. Futhermore, a loud environment increases peoples' general stress. People staying in loud environments have been shown to have a higher concentration of stress hormone in their blood. Thus there is a connection between stress-related illnesses and loud sound.

Another key issue seems to be subjective acoustic privacy. Apart from the fact that decreased acoustic privacy increases stress in general, overhearing speech or other communication sounds is particularly serious. The explanation for this is that there is a fundamental difference between communicative sounds and non-communicative sounds. Our brains are trained to interpret the surrounding world in order to optimise our reactions, and the brain reacts immediately to communicative sounds. In short, communicative sounds activates the brain much more than non-communicative sounds. A constant activation of the brain by e g people talking nearby gives a constant activation of the brain and thus it is hard to concentrate on other things. This effect is further emphasized by the fact that we can shut our eyes, but not our ears.

The outcome of this is that in an environment which is acoustically dominated by people talking the job satisfaction decreases, and with this ultimately the well-being. To constantly feel that you are not doing your job properly does affect your well-being, and your health.

On top of this, there is a psychological effect which is a bit like you cannot unlearn what you have learned. The explanation is that if you have interpreted a special attribute in the acoustic environment, e g a person talking with a characteristic voice or that there is a constant hum in the ventilation system, it is virtually impossible not to listen to it. Each time you hear this attribute it gives an unwanted activation to your brain.

To summarize: The most common effect of sound on our well-being and health is the disturbance of other people talking or other sounds with clear attributes or meaning. Such sounds results in unwanted attention in your brain and may result in annoyance, or ultimately health issues.