When noise is dangerous

Even if you did spend your youth listening to music at full blast, there is still plenty you can do to minimize any further loss. Several factors are important for the health of your hearing as you age.

Experts estimate that, worldwide, as much as 50 per cent of hearing loss is preventable. First, it is worth identifying and being aware of the elements of modern life that can threaten good hearing.

• This will not only help you to protect yourself against hearing loss and tinnitus (persistent, irritating sound in the ears) by reducing the noise levels in your environment, but also allow you to shield yourself from distraction and get a better night's sleep.
• Prolonged exposure to noise makes people tired and irritable; noise in the workplace increases accident rates and makes it harder for workers to relax and unwind at the end of the day.
• Noise can create learning problems for schoolchildren and stimulate aggression. Unwanted background noise has been shown to increase the level of cortisol, a stress hormone, that is excreted in urine.
• High noise levels have been associated with increased headaches, heartburn, indigestion, stomach ulcers and a type of dizziness known as vertigo.

• A study by researchers at Johns Hopkins University in Baltimore showed that noisy hospital environments slow down the pace of healing in patients and cause short-term memory lapses; they also increase the risk of medical errors and lead to higher stress levels among staff.
• Noisy environments are related to increased heart rate, blood pressure and blood cholesterol levels, and there is a growing suspicion that noise may contribute to heart disease.

• The World Health Organization warns that long-term noise exposure above 67 to 70 dB (equivalent to moderate traffic noise) can lead to high blood pressure, raising the risk of cardiovascular disease.
• Studies have shown that even moderate noise over a single eight-hour period can increase your blood pressure significantly.
• Other research suggests that exposure to noise above 50 dB during the night can lead to chronically raised cortisol levels that may increase the risk of heart attacks. Anything above 45 dB is likely to interfere with sleep.
• Both high blood pressure and cardiovascular disease have been linked with increased rates of hearing loss.
• In fact, the detrimental effects of noise are so widespread that some experts are calling for "second-hand noise" — intrusive sounds produced by other people — to be treated as a health hazard, just like the passive inhalation of second-hand cigarette smoke.