Noise-induced Hearing Loss: Causes, Symptoms & Treatment

Noise-induced hearing loss increasingly affects young people. Noise-induced hearing loss caused by long-term exposure to noise is usually not curable.

What is noise-induced hearing loss?

Noise-induced hearing loss is also known as sensorineural hearing loss. Noise-induced hearing loss usually develops due to long-term exposure to sound levels of high severity. Noise-induced hearing loss as a chronic noise trauma, for example, must be distinguished from acute noise trauma, which can occur after only a few minutes as a result of sudden loud sound levels. In Germany, noise-induced hearing loss is one of the most common occupational diseases. An increased risk of suffering from noise-induced hearing loss is particularly prevalent among people who work in traditionally noisy areas; these include, for example, jobs in the metal industry, woodworking, or working on printing presses. However, long-term exposure to noise from very loud music can also lead to noise-induced hearing loss. A characteristic of noise-induced hearing loss is often that the hearing impairment is concentrated at certain frequencies, while other frequencies are less affected. Noise-induced hearing loss is particularly noticeable when an affected person is exposed to background noise (such as background music).

Causes

Noise-induced hearing loss is caused by long-term noise affecting the oxygen supply to the hair cells in the ear. Due to the lack of oxygen supply, the metabolism of corresponding hair cells is disturbed in noise-induced hearing loss. As a result, an affected person suffers from a long-term functional disorder in the area of hearing. According to experts, the threshold value above which long-term noise exposure can lead to noise-induced hearing loss is 85 dB on average. Noise exposure of this level is roughly equivalent to noise exposure from a circular saw.

Symptoms, complaints and signs

Acute noise-induced hearing loss usually occurs immediately after exposure to high levels of noise. Depending on the cause, symptoms can last from a few minutes to hours (such as after attending a loud rock concert) or days, weeks and months (after a blast trauma). In general, acute noise-induced hearing loss is manifested by a mild to moderate decrease in hearing ability. In addition, noticeable ear noises such as whistling and tinnitus occur. The symptoms usually disappear on their own after a recovery period. Chronic noise-induced hearing loss develops gradually. At first, those affected perceive only the high tones more poorly, before the hearing loss also occurs in other frequency ranges. Patients then have difficulty perceiving background noise or distinguishing between the voices of different people. This is often accompanied by disturbing noises such as tinnitus. In the chronic form, permanent hearing problems are likely. If chronic noise-induced hearing loss is treated, however, progression of the symptoms can be prevented. In the best case, an improvement in hearing ability can be achieved through targeted protection of the hearing. In children and adolescents, chronic noise-induced hearing loss always has permanent consequences. Permanent damage to the auditory canals is also to be expected in the acute form.

Diagnosis and course

Noise-induced hearing loss can be diagnosed with the help of hearing tests; if noise-induced hearing loss is present, it is usually indicated by the fact that those frequencies are most affected by hearing impairment that have been most exposed to long-term noise exposure. Another indication of a noise-induced hearing loss is when a person has difficulty understanding speech, especially when it is combined with background noise. As a rule, noise-induced hearing loss takes a gradual course and builds up over a period of years. Since noise-induced hearing loss is mainly concentrated at certain frequencies, it is often not initially perceived as hearing loss by those affected. In the course of a noise-induced hearing loss, the hearing impairment may be accompanied by ringing in the ears. If a person already has a noise-induced hearing loss, it is usually no longer possible to cure it.

Complications

Noise-induced hearing loss causes those affected to suffer from hearing loss.This can either be congenital or acquired through certain events or very loud noises. As a rule, noise-induced hearing loss can no longer be cured and is therefore an irreversible symptom. Those affected are severely restricted in their everyday life and can no longer communicate easily with other people. Noise-induced hearing loss also significantly impairs the ability to assess dangers, causing sufferers to underestimate or misjudge certain dangers. Furthermore, it is not uncommon for patients to find it difficult to speak. Sometimes, in addition to the hearing loss itself, patients suffer from ringing in the ears, which can lead to severe psychological complaints or depression. It is not possible to make a general prediction as to whether the noises in the ear can be cured or will remain permanently. Furthermore, the noises in the ear can also lead to disturbances in concentration or irritability of the patient. The quality of life is considerably limited and reduced by the noise-induced hearing loss. It is not possible to treat noise-induced hearing loss. With the help of hearing aids, the limited hearing ability can be partially remedied. However, a completely positive course of the disease does not occur. However, the patient’s life expectancy is not affected by noise-induced hearing loss.

When should one go to the doctor?

People who are exposed to loud environmental noises for professional or personal reasons should attend a hearing check-up at regular intervals. If habitual hearing declines, a doctor is needed. If the affected person has been exposed to a single loud noise in the form of a bang or similar, it is advisable to consult a doctor. If numbness occurs or sounds can no longer be differentiated as usual, a consultation with a doctor is necessary. If ringing in the ears occurs, there is a headache or a feeling of pressure inside the head, a doctor should be consulted. In case of disturbances of night sleep, problems falling asleep or general sleep disturbances, a doctor should be consulted. In case of a whistling in the ear, disturbances of balance or pain inside the ear canals, it is advisable to initiate closer medical examinations. If the affected person notices that the position of the volume control changes considerably during the daily use of communication devices, if warning signals from the surroundings can no longer be heard or if it is difficult to locate the received sound waves in the right direction, a doctor must examine the signs and initiate treatment. There is an increased risk of accident and injury, which can pose a threat to life. If there are behavioral abnormalities or mood swings, it is also recommended to seek medical attention.

Treatment and therapy

Noise-induced hearing loss usually cannot be treated causally. This is different in the case of an imminent acute noise trauma after a sudden, very loud noise exposure; unlike noise-induced hearing loss, it is possible here to stimulate blood flow to the hair cells in the ear by infusions to promote the metabolism of these cells. A supply of oxygen and/or administration of cortisone-containing drugs can also be used after an acute noise trauma. If noise-induced hearing loss is diagnosed, medical professionals usually recommend avoiding further exposure to high levels of noise to prevent further damage to hearing. In order to be able to positively influence hearing restrictions in the case of noise-induced hearing loss, one possibility is the individual fitting of a hearing aid. Such hearing aids, which can also be used for noise-induced hearing loss, usually have a microphone, a loudspeaker and an amplifier. The task of the microphone in a hearing aid is first to pick up ambient noise and convert it into electrical signals. With the help of the amplifier, various frequencies are then boosted in noise-induced hearing loss and transmitted to the ear as sound waves through the speaker.

Outlook and prognosis

The prognosis for noise-induced hearing loss is unfavorable in most cases. Impaired hearing due to exposure to noise causes damage to the hair cells in human hearing. These cannot be repaired despite all medical advanced developments and possibilities. The damage is permanent and, according to the current state of knowledge, irreparable.Therefore, under optimal conditions, hearing loss can be expected to remain constant for several years. However, it must be taken into account that in the course of life there is a process of degradation of the functional activity of the hearing. Therefore, a further decrease in hearing usually occurs in the natural aging process. The prognosis is significantly worse if the triggering stimuli persist unchanged. Even if hearing loss is already present, further noise can cause the remaining hair cells to fail. In the human auditory canal, there are approximately 3000 inner hair cells. These are largely responsible for hearing. If they are damaged due to external noise effects, the intake of medication or diseases, they can no longer carry out their activity. The more hair cells are damaged, the worse the hearing. Therefore, in order to make a prognosis, it should be examined what the circumstances of the person’s life are. In addition, education about the effects of other interfering factors must be provided.

Prevention

Especially for people who are regularly exposed to high levels of noise, it may be important to take early measures to prevent noise-induced hearing loss. These measures include, for example, regular check-ups with a specialist and, above all, wearing appropriate hearing protection during exposure to noise. In the leisure sector, noise-induced hearing loss can be prevented, for example, by avoiding excessive volumes of music played through headphones or when going to a disco.

Aftercare

Because the prospect of complete recovery from noise-induced hearing loss is rare, aftercare focuses on helping people gain confidence in dealing with the condition. Those affected are severely restricted in their everyday lives, and sometimes they can no longer communicate with their environment as usual. This often leads to social isolation. Since those affected no longer take an active part in life, they often withdraw into themselves. This can lead to depressive moods. For this, the help of a professional psychologist should be sought in order to better understand and deal with one’s own situation. Affected people underestimate certain dangers due to their hearing loss. It cannot be predicted whether the noises in the ear will remain permanently or can be cured. The noises in the ear can lead to persistent irritability and disturbances in concentration in those affected. Quality of life is significantly reduced by noise-induced hearing loss. Affected persons are constantly dependent on help from those around them. It is therefore important to make people aware of the disease so that they can respond better to those affected. Special hearing aids can sometimes partially eliminate noise-induced hearing loss. A positive course of the disease will not occur. Life expectancy is not affected by the disease.

What you can do yourself

People who suffer from hearing loss can take a critical look at their own lifestyle and possibly make changes. Strong noise influences should generally be avoided. These include listening to loud music, watching television too loudly or talking too loudly on the phone. When attending concerts or discos, it is advisable to be equipped with adequate hearing protection and not to position yourself next to a loudspeaker. Work with a high noise level should be avoided or should also only be undertaken with protective equipment. Places where there is a lot of noise should be left. These include construction sites or airport approach paths. In addition to low noise exposure, a healthy lifestyle is necessary. Alcohol and drugs should always be avoided. Medications whose side effects cause damage to the auditory canals should only be taken after consultation with a physician. Stress, hectic activity and psychological strain should also be minimized. Sufficient sleep and the clarification of emotional problems are important to maintain health. Mental as well as physical overload should be avoided. A healthy and balanced diet and sufficient exercise improve overall well-being. This supports successful coping with mental challenges. Circumstances that trigger dissatisfaction over a longer period of time should be changed and optimized.