Hearing Loss: Definition & Facts
According to the World Health Organization (WHO), hearing loss, also called hypacusis, affects about 430 million of the world's adults. Among those over 65, it is already one in two to one in three. Hypacusis is characterized by the fact that the perception and processing of acoustic information is disturbed. While in the healthy hearing process sounds and voices are processed by the brain through the reception and transmission of sound waves and thus heard, the understanding of hearing impaired people is limited.
However, not all hearing loss is the same: On the one hand, different degrees of severity are distinguished, ranging from mild impairment to complete deafness. Depending on the severity, one speaks of mild, moderate, or profound hearing loss. On the other hand, different types of hearing loss are to be distinguished, which are individually expressed as well as have different underlying causes. Furthermore, in addition to permanent hearing impairments, only temporary limitations in hearing are possible. Damage to the sense of hearing canoccur at any time of life: It can be congenital, occur in childhood or only in increasing age, with the latter variant being particularly common.
Hearing loss/hypoacusis symptoms
It varies whether symptoms refer to only one ear (unilateral) or both ears (bilateral). If the condition is bilateral, the symptoms on each side may differ. The following signs may indicate hearing loss:
- Whispers or soft sounds are difficult to understand
- Conversation and understanding in ambient/background noise is difficult
- Certain frequencies or volumes are inaudible (increasing deterioration is often evident here)
- Group conversations are stressful
- Voices are perceived muffled
- Difficulty understanding high-pitched voices (e.g., of children)
- Cases of hearing loss in relatives may further increase the risk for hearing impairment
In children and babies, a number of other early symptoms speak to a possible hearing impairment. To find out what they are, read here.
Hearing loss/hypacusis causes: Where does hearing loss come from?
Many causes can cause hearing loss. In the case of congenital hearing impairment, genetic disposition is particularly responsible, but damage during pregnancy and in the birth process can also potentially damage hearing. Later in early childhood, infections and excessive noise in particular form a significant risk factor. Age-related hearing loss (presbyacusis), on the other hand, is attributed to a combination of age-related wear and tear, decades of exposure to noise, and hereditary underpinnings.
Other causes of hearing loss at any age, which vary according to the type of hearing loss, include:
- Constipation of the ear canal
- Chronic otitis media
- Hearing loss
- Alcohol and tobacco
- Injuries to the ear or head
- Excessive noise
Hearing loss/hypacusis diagnosis: how is hearing loss diagnosed?
For diagnosis, the first step is usually an examination of both ears by an otolaryngologist, including a medical history interview. Here, an otoscopy can provide information about the presence of inflammation or blockage. Subjective tests are also used to create a sound threshold audiogram. To localize the problem in the middle or inner ear and determine whether unilateral or bilateral damage is present, it is also possible to check how long the sound of a tuning fork is perceptible to the affected person.
Objective tests, on the other hand, measure sensory cell or brain activity. For example, otoacoustic emission is studied using measurement microphones. This determines whether click sounds entail a response from the hair cells. In functional hearing, the hair cells contract when a sound hits them. In another test, speech audiometry, patients are asked to repeat numbers and words that are played to them. Electrocochleography provides information about sensory cell activity. To assess brain response, brainstem audiometry can be used, which records the brain's response to sounds. This form of testing is especially used when the cause of hearing loss is suspected to be in the auditory nerve or in deeper auditory areas. Cortex audiometry works similarly, but specifically focuses on the activity of the cerebral cortex.
Consequences of hearing loss/hypacusis
Untreated hearing loss may entail far-reaching consequences, both professionally and personally. The lack of hearing performance may cause individuals to withdraw from their social lives or even place themselves in complete isolation. This in turn leads to an increased risk for depression. Physically, consequences include exhaustion, fatigue, headache, as well as increased potential for accidents and falls. The observation of an increased mortality rate when not treated can probably be attributed to this very risk of accidents. Even cognitive effects of untreated hearing loss can occur, promoting memory decline, for example.
Treatment: what to do about hearing loss?
To minimize the risk of depression or hearing-related accidents, appropriate treatment is strongly advised. Which treatment is promising depends largely on the type and degree of hearing loss. You can read a partial selection of treatment options here:
- Hearing loss due to inflammation: If the hearing loss is the result of inflammation, drug treatment is usually already sufficient.
- Hearing loss due to damage to the sensory cells: If the sensory cells are too damaged or other causes are present, the classic treatment method lies in the use of hearing aids or implants.
- Hearing loss due to hearing loss / acoustic trauma: Here infusions, which are mixed with drugs, can be used.
- Hearing loss due to ear congestion: In the case of congestion, cleaning by an otolaryngologist is usually sufficient to restore hearing.
- At this point, infusions containing medication can be used.
- Inherited hearing loss: Speech therapy treatment aims to restore the ability to communicate with the environment. Most often, speech therapy treatment is combined with wearing a hearing aid or implant.
If you suspect hearing loss in yourself or loved ones, do not hesitate to consult a doctor. In the best case, however, the hearing impairment is avoided before it can even occur. Preventively, for this purpose, care should be taken to wear suitable hearing protection or an ICP hearing aid during noisy work. But even in private, noise exposure can be damaging. Keep that in mind when regulating the volume of your music.
Smoking and alcohol are also conditioning factors that can increase the risk of hearing loss. If you want to reduce the risk of permanent damage from infections, you should also learn about vaccinations against infectious diseases (such as measles and mumps). If you suspect you may have hearing loss, you can take a free online hearing test to get an initial assessment regarding your suspicions.
Types of hearing loss
Hearing loss, also called hypacusis, generally describes the restriction of the perception of speech and sounds. Depending on the severity, it is referred to as minor, moderate, or profound hearing loss, which can also extend to deafness or complete hearing loss. Damage to the sense of hearing can occur at any time of life, although an age-related form is particularly common. There are a number of specific subtypes of hearing loss that vary in their causes, symptoms, and treatment options.
One of the most common forms of hearing loss is presbyacusis, or age-related hearing loss. As the name suggests, hearing loss in this case occurs with increasing age. The cause is not fully known in this case, but can be attributed to a combination of the following causes:
Typical of presbycusis is bilateral, equally affected ears, as well as gradual deterioration in hearing performance. At first, hearing in noisy environments, the perception of soft sounds and particularly high frequencies is difficult. The lack of perception of acoustic information progressively spreads to other frequency ranges as well as loudness.
conductive hearing loss is characterized by limited to no sound waves reaching sensory cells in the inner ear. Reasons for this are mostly in the ear canal itself, which blocks, for example, by blockage or malformation a passage. In some cases, however, the interference factor can also be localized in the middle ear, which can sometimes be restricted by infection, malformation, or a tympanic effusion. The classic symptomatology consists of a quieter, muffled sound perception of all pitches equally.
In the presence of inflammation, congestion, or the common cold, hearing is usually only temporarily impaired. With antibiotics or minor surgery in the ear, symptoms can be lessened or blockages can be relieved. Ear malformations of the outer or middle ear, otosclerosis, tumors, mumps, measles, or head trauma, on the other hand, are more likely to cause long-term hearing loss. If this is severe, surgery may be necessary.
Sound perception hearing loss
Compared with conductive hearing loss, sensorineural hearing loss succeeds in conducting sound but fails to identify and interpret auditory impressions. Thus, the conduction of acoustic impulses through the auditory nerve succeeds, resulting in the hearing of sounds, but further processing in the brain fails, which is why actual perception of what is heard is also prevented. This type of hearing loss occurs, for example, after strokes or in brain inflammation and hemorrhage, but is also caused by infections such as measles, mumps and shingles.
Sound sensorineural hearing loss, or sensorineural hearing loss, is characterized by irreparable dysfunction in the inner ear. An initial sign may be limited speech comprehension. This is caused by the drum and ossicular chain transmitting sound waves, but they are not properly transmitted and processed. Damage to the hair cells in the inner ear is responsible, preventing the hair cells from doing their job of amplifying and converting electrical signals. Possible causes of sensorineural hearing loss include presbyacusis, noise damage, hearing loss, poisoning, and skull injury. However, it can also be attributed to pre-existing conditions (metabolic disease, diabetes, circulatory disorder, etc.) and hereditary factors.
In this form of hearing loss, a distinction must also be made between sensory, neural and sensorineural sensorineural hearing loss.
|Sensory sensorineural hearing loss||Neural sensorineural hearing loss||Sensorineural sensorineural hearing loss|
|locates its cause in the cochlea in the inner ear: the sensory cells of the cochlea are responsible for transmitting impulses to the brain. If there is damage, a hearing loss occurs, which in turn can manifest itself in a sensory sensorineural hearing loss.||In contrast, is due to a damaged auditory nerve. If this is the case, impulse transmission through the auditory nerve is impeded.||ultimately affects both the neural and sensory functional areas.|
When discrimination loss occurs, there is difficulty perceiving determined frequencies. Spoken words are heard but not always understood because certain parts of the word are missing. Signs of such a loss consequently include difficulty following a conversation, especially in groups or in the presence of impressive background noise, and perception of spoken words as unclear. Symptoms can occur in any age group. In addition, hearing loss can relate to both high and low frequencies and is accordingly referred to as either high-frequency- or low-frequency hearing loss. Individuals in whom the mid-frequency range is affected suffer from mid-tone hearing loss.
High frequencies are difficult to perceive for people who suffer from high-frequency hearing loss. High-pitched sounds are counted as frequencies from 2000 hertz upward. Thus, in conversations, some sounds - such as s, f, h - are particularly difficult to hear, and there is also a generally dull perception of the environment. High-pitched voices, birdsong, and high-frequency signals (e.g., the beep as a signal of the completed washing process) remain inaccessible to affected individuals. A striking feature of high-frequency hearing loss is that the volume of hearing remains mostly unchanged and there is only a feeling of understated hearing.
People who have profound-deafness cannot hear low frequencies of 2000 hertz or lower. This is a sensorineural hearing loss because there is damage to the hair cells. In most cases, the hearing volume itself is not affected, but comprehension is still impaired. Age-related wear and tear as well as noise, diseases and infections can all be reasons for such hearing loss.
Mid-tone hearing loss results from disturbance of the cochlea (hearing cochlea) in the inner ear and counts as sensory internal ear hearing loss. While usually the mid-frequency range is most sensitive, individuals with mid-tone hearing loss have this range closed off. Even in the absence of background noise, affected individuals always find it more difficult to understand speech, although low and high tones can be heard well. A mid-tone hearing lossis hereditary, usually occurs relatively early, and is characterized by progressive deterioration. At its most severe, it can cause hearing loss bordering on deafness, usually affecting both ears equally. Prevention of the inherited type of hearing loss is not possible, so the only treatment left is to treat the symptoms with the aid of a hearing aid.
Broadband hearing loss
Another subtype of sensorineural hearing loss is broadband hearing loss. This is a combined hearing loss of low-tone-, mid-tone-, and high-tone hearing loss in which the entire cochlear area is damaged. Consequently, the hair sensory cells can no longer pick up acoustic information and hearing of all frequency ranges becomes limited. However, the expression of hearing loss may differ between frequency ranges. While genetic causes cannot be prevented, hearing loss caused by noise can be avoided by appropriate hearing protection. Hearing aids are used to compensate for broadband hearing loss.
Combination hearing loss
When two to three types of hearing loss occur together, it is called combined hearing loss. An example of this is a combination of sound conduction and sound conduction hearing loss, which can occur with blast trauma, the sudden onset of extreme noise exposure right next to the ear. Here, there is a risk of both rupturing the eardrum and damaging the hair cells in the inner ear. The result is limitations in the area of sound conduction and sound perception.
Auditory processing and perception disorder
Auditory processing and perception disorder (AVD) describes the condition of impaired hearing despite actually healthy ears. Limitations are particularly noticeable in recognition and discrimination of sounds. In addition, AVWS has an influence on cognitive processes such as memorization and foreign language acquisition. Fordiagnosisthe ability to distinguish phonemes (speech sounds) and the length of vowels in different words is examined. If this reveals abnormalities or a discrepancy between educational level and demonstrated performance - in addition to poor retention of numbers and syllables - AVWS may be present.
Hearing loss in one ear
Sudden hearing loss in one ear is likewise known by the term hearing loss. After a hearing loss, hearing is worse or not heard at all, as well as dull ear pressure is often felt. Tinnitus and dizziness are also possible. Various origins can promote the onset of hearing loss, with circulatory problems thought to be a major cause. If there is no improvement after a few days or if the symptoms are particularly severe, an otolaryngologist should be consulted to initiate appropriate treatment. In this context, not every case of sudden hearing loss is due to a hearing loss; clogging or inflammation of the ear can also trigger unilateral hearing impairment.
Surditas, better known as deafness, is when there is a complete lack of acoustic perception of sounds. Both causes in the ear itself and in the auditory pathway in the brain can lead to deafness. Genetic factors, infections or drug abuse during pregnancy, as well as complications at birth, are factors that promote congenital deafness. Later in life, deafness can result from infections, medications, tumors, noise, or chronic ear disease (e.g., otosclerosis).