Effects of noise on health. Acoustic trauma.

  • 1 de January 2020
  • Instituto de Otorrinolaringología Andaluz
  • News

The deafness associated with acoustic trauma and the importance given to noise pollution are becoming more frequent. The effects of noise on health go beyond damage to the ear itself. We explain the causes that cause this problem and some tips to reduce the impact of noise on our health.

Noise pollution

The noise in our environment is one of the most important environmental concerns for citizens. According to the 2018 Ecobarometer of the Junta de Andalucía, noise is one of the main environmental complaints in the urban environment, at the level of air pollution or the lack of green areas. This concern about the effects of sound aggression is already in Sibaris, in the year 600 a. C., a city that belonged to Magna Grecia and was known for the refinement of its customs (“Sibaritas”). Its rulers banned working metals within urban boundaries.

Noise as a harmful element for the human being is a social phenomenon, which appears with progress and leisure. The sound energy of some natural phenomena such as thunder, storms … is limited in duration and intensity and hardly affects our health.

Noise produces not only lesions at the auditory level but also produces lesions in other organs and systems.

When is a noise to our ear harmful?

In general, injuries to the ear of noise are caused by two factors: noise intensity and exposure time. The noise begins to be harmful from 80 dB of intensity, and in the same noise, the longer the exposure time, the greater the injury is established. As an example we can highlight the intensity of noise in normal life situations:

In the classroom the noise intensity is between 40 and 80 dB.
The intensity at which we hear music on players, mobile devices … is in the range of 70 to 100 dB.
In nightclubs and entertainment venues the noisy environment is between 85 and 115 dB.

In addition to these two factors, individual sensitivity to sound also intervenes. In general, the following scheme can be established as a rule.

Sound level Exposure time Effect
<70 dBA Independent No hearing damage
> 85 dBA More than 8 hours a day Hearing damage

The intense noises above 80 dB, maintained over time cause enzymatic alterations in the cells responsible for hearing in the inner ear (inner and outer hair cells). As a result of excessive metabolic work, these cells that end up being destroyed, destruction that is irreversible. This causes the clinical picture of chronic sound trauma, characterized by:

Permanent deafness (hearing loss) that will intensify if exposure to noise continues.
Tinnitus (tinnitus or noise in the ears).

A much more intense noise, such as that caused by an explosion, causes a pressure wave to accompany the noise. It can cause, in addition to the aforementioned symptoms, lesions in the ossicles chain and / or in the tympanic membrane.

In the case of any of these symptoms, audiological assessment is necessary in the ENT office.

Noise not only affects the ear

Prolonged exposures to noise of intensities close to 30 dB during sleep, produce alterations in the rhythm and quality of the same, with the appearance of insomnia, sleep restructuring, frequent awakenings and in general a poor quality of rest. This will determine increased fatigue, lack of concentration, decreased work and intellectual capacity, as well as increased irritability.

It is described, with sufficient level of evidence, the appearance of cardiac arrhythmias, arterial hypertension and even myocardial infarction, in direct relation with prolonged exposures to noises of intensity of 55-60 dB.

There are also negative effects of prolonged exposure to loud noises on the immune and endocrine system.

How to prevent the harmful effects of noise
Use personal music players cautiously, never reaching the maximum volume and ensure that music cannot be heard by other people. Every time we see more teenagers with hearing problems related to exposure to intense noises for a long time.
Avoid leisure activities with excessive noise levels (concerts, discos, etc.) and in any case, do not stand near speakers and similar equipment.
Get used to limiting the volume of radios and televisions to a reasonable level, since they are usually used at a high volume by habit and not by necessity.
Respect the rest hours of others, avoiding noisy activities.