Definition – What is presbyacusis?
Age-related hearing loss is defined as a hearing loss that naturally diminishes with age. It begins with a hardly noticeable hearing loss around the age of fifty and gradually deteriorates over time. Those affected notice this at the beginning, especially in an increasing inability to perceive high-pitched sounds clearly and that background noise can no longer be filtered out of a conversation so well. Usually both ears are equally affected by the change.
Causes
The most important cause of presbyacusis is already in its name. It is the advancing age that leads to a reduced hearing ability. The hair cells in the inner ear, which are responsible for the perception of sounds and noises, wear out naturally.
With every audible sound, they are deflected in one direction to varying degrees depending on the volume and pitch of the sound. Over time, their flexibility and strength decreases, just as it does with other parts of the body. Comparable to presbyacusis are thus age-related changes in the skeleton, as in the case of osteoarthritis.
In the case of hair cells, especially very high tones in the high-frequency range require a strong deflection of the hair cells. It is therefore logical that this tone range is affected first. In addition to the hair cells, age-related changes in the brain also have an influence on presbyacusis.
This is because the flexibility in thought processes and the processing of new stimuli decreases with age as the brain substance decreases. This does not mean that older people become dumber. Rather, it means that they are no longer able to adapt so well to current stimuli.
Sounds and noises are acoustic stimuli and are therefore also affected by the changed processing. Environmental factors such as increased noise exposure during the course of life can lead to earlier onset of presbyacusis. A noise-induced hearing loss cannot, however, be equated with presbyacusis. Medication such as specific antibiotics or infections are rarely the cause of significant hearing loss in old age. Although they can also damage the hair cells, they do not usually cause a typical presbyacusis.
Diagnosis
The diagnosis of age-related hearing loss is made by an ENT physician. The doctor can perform various tests for this purpose. The choice of the hearing test depends on the cooperation and abilities of the patient.
As a standard, an audiometry is usually carried out, which shows the hearing range of the affected person in a diagram in comparison to normal healthy people. To perform the test, the patient must put on headphones and press a button when a sound is heard in one ear. A significant deviation in the high-frequency range indicates a presbyopic hearing loss.
An audiogram is a graphical representation of subjective hearing. The horizontal axis represents the frequency range in Hertz and the vertical axis the sound pressure level in decibels. The data entered are taken from the previously conducted hearing test with the test person and result in the so-called “hearing curve”. An audiogram of a normally healthy person resembles a horizontal line around zero decibels. In the case of presbyacusis, the curve decreases significantly from about one thousand hertz by about forty decibels until it reaches a plateau again in the frequency range around four thousand to eight thousand hertz.
