Depending on their duration and frequency, loud noises can damage the ear and lead to permanent hearing loss. At very high noise levels, even brief exposure lasting just a few minutes can cause irreversible damage to the inner ear. The delicate hair cells in the inner ear, which are responsible for sound transmission, can be destroyed. Once damaged, they cannot be repaired, which can lead to hearing loss or even deafness.
The pain threshold for the ear is at noise levels of 120-140 dB(A) (for comparison: 120 dB(A) corresponds to the noise of a jet plane taking off at a distance of about 100 metres). Noise levels of 100 to 110 dB(A), such as those found in discotheques or when listening to music with headphones, can also be harmful. Frequent visits to discotheques and listening to loud music through headphones are known causes of hearing damage, especially among young people. Those affected often do not notice the hearing damage until years later, when the loss is irreversible.
The German Medical Association warns of high costs for social security providers and employers and estimates that, given current music listening habits, around 10 percent of young people could have a detectable hearing loss of 10 dB(A) or more after 10 years.
Loud children's toys can also cause health problems. Toys such as cap guns or crackling figures can reach noise levels of 100 dB(A) and above when held close to the ear. This volume is often not perceived as being so loud, but can still cause permanent hearing damage. It is advisable to keep a safe distance from such toys or avoid them altogether.
Even lower noise levels can lead to hearing problems in the long term. Permanent hearing damage can be expected at an average noise level of 85 dB(A) over an eight-hour working day.
Even at levels below the threshold for hearing damage, noise can interfere with communication, rest and relaxation. The so-called extra-aural effects of noise include annoyance, sleep disturbances, increased blood pressure, heart rate and respiratory rate, and increased release of stress hormones. This increases the risk of cardiovascular disease.
Communication problems can arise at continuous noise levels as low as 50 dB(A) outdoors. According to the WHO, 55 dB(A) should not be exceeded outdoors during the day in order to avoid significant annoyance. For the healthy development of children, the WHO also recommends a maximum value of 55 dB(A) when playing outdoors. At 55 dB(A) and above, impairments to mental and social well-being are to be expected. A study by the German Federal Environment Agency shows that at a continuous traffic noise level of 65 dB(A) during the day, the risk of heart attacks in men increases by 30 percent. At night, there is a significantly increased risk of stress-related illnesses at 55 dB(A) and above.