Surditas (Taubheit): Definition, Ursachen, Symptome, Folgen, Diagnose

What does the medical profession mean by "surditas"?

Surditas, more commonly known as deafness, is characterized by complete deafness of one or both ears. It can be further divided into clinical and practical deafness: In practical deafness, the degree of hearing loss borders on deafness, but partial function of the inner ear is still detectable. This case occurs, for example, in combined hearing loss. The diagnosis of clinical deafness, on the other hand, is characterized by a complete loss of function of the inner ear.

Many are familiar with the term "deaf and dumb" in the context of deafness. However, surditas does not necessarily result in muteness. Consequently, it cannot be concluded that deaf persons are automatically mute. However, deafness sometimes occurs in combination with muteness and/or blindness. One factor influencing the occurrence of muteness is whether the hearing impairment is congenital or acquired and, consequently, whether unimpaired verbal language acquisition has occurred.

Surditas left/right/bilateral: symptoms and consequences

Deafness can affect both ears or only the left or right ear. The distinction between whether both or only one ear is affected is important because the accompanying symptoms or consequences sometimes differ massively.

Single-sided deafness

  • As a rule, hearing is very severely impaired
  • Remaining hearing is possible with the unaffected ear, however
  • It is noticeable that affected persons do not react or react with delay to (loud) noises
  • Language acquisition is largely normal
  • Limited directional hearing

Bilateral deafness

  • No hearing sensation present
  • Oral communication mostly not possible
  • Disturbed/delayed language development, especially in congenital deafness
  • Special consideration should be given to individuals who have acquired surditas only in the course of their lives. Those affected by this have mostly undergone normal language acquisition and can therefore more easily resort to the articulation of spoken language.
  • In children deafness, in addition to delayed speech development, manifests itself early in a lack of response to speech, articulatory difficulties and the choice of a high volume when consuming media.
  • Because there is a close relationship between the sense of hearing and the sense of balance, dizziness is also often associated with deafness.

Surditas/ deafness: causes

What causes underlying surditas, differs in each individual case. Likewise, various combinations of causes are possible:

  1. Limitations in sound conduction: Sound cannot be conducted to the inner ear via the middle ear as usual. This may be due to damage to the ossicular chain, which serves to amplify sound.
  2. Limitations in sound perception: The transmission of sound to the inner ear is not affected, but the transmission of signals to the brain is. Consequently, no processing of what is heard takes place. Such a restriction can be caused, for example, by the disturbance of the auditory nerve.
  3. Psychogenic hearing disorder: In rare cases, a mental illness leads to the influence of hearing. In this case, no damage to the ears can be detected, but a reduced hearing performance in the hearing tests.

A congenital surditas may be due to the following factors:

  • Genetic predispositions
  • During pregnancy:
    • Infections of the mother
    • Drug use
    • Certain medications
  • At birth:
    • Oxygen deficiency
    • Brain hemorrhage

The acquisition of a surdity can be attributed to these causes:

  • Prolonged ear infections: may involve damage to the middle and inner ear
  • Meningitis or encephalitis
  • Some medications:
    • Chemo-therapeutics
    • Diuretics (dehydrating agents)
    • Various antibiotics
    • Acetylsalicylic acid
  • Tumors
  • Noise damage
  • Circulatory disorders
  • Hearing loss
  • Chronic ear disease (e.g., otosclerosis)

Diagnosis of deafness/surditas

To diagnose "deafness", an ear, nose and throat specialist must be consulted. This first ascertains in a anamnesis interview, whether risk factors for a corresponding disease are present. During an otoscopy (otoscopy), the ear canal is then examined. This allows the exclusion of other causes, such as middle ear impairment due to obstruction, but does not allow conclusions about hearing performance. Therefore, a series of tests follows to check hearing performance, localize causes of deafness, and make a diagnosis.

The following tests are used to diagnose surdity:

Subjective tests

To distinguish whether a sound conduction or sound perception disorder is present, the Weber test is used. In this, the doctor places a tuning fork on either side of the head. In cases of deafness, the bone conduction is often still functional, making it possible to hear the sound in the Weber test. Thus, it is possible to check whether the sound is heard equally in both ears. If the patient hears the sound louder on the diseased side, this indicates a disturbance of sound conduction, and on the healthy ear it indicates a disturbance of sound sensation.

The Rinne test reveals potential differences in the patient's bone and air conduction performance as it is evaluated along with the Weber test. It is also performed with a tuning fork: it is placed on the bone behind the ear until the sound is no longer audible. The fork is then held next to the ear, where the sound should be audible again. If the sound is not heard, this indicates deafness.

In addition, the sound threshold audiogram provides information about the hearing threshold or the decibel number at which the patient has a hearing performance. The threshold is measured in tona audiometry by playing different loud and high-pitched sounds through headphones and bone-conduction earphones. Based on this, an audiogram can be created as a visualization of hearing. The later sound perception exists, the more pronounced the hearing loss. In addition, speech audiometry records speech comprehension. For this purpose, the patient is asked to name and repeat words and sounds that are played to him over headphones.

To distinguish hearing loss, i.e., impairment of auditory perception, from complete loss of auditory perception, i.e., deafness, sound threshold audiometry must be considered. If a hearing loss of 100 decibels or more is shown in the main speech area, the affected person is considered deaf. The main speech range is considered to be the frequency range in which the main part of communication takes place.

Objective testing

In tympanometry, a probe is inserted into the ear so that it is sealed airtight. The probe then emits a sound to measure how much momentum the eardrum has. The result allows conclusions to be drawn about how well the middle ear is functioning and shows if there is a tubal disorder or a break in the ossicular chain.

With the help of stapedius reflex measurement, the onset of the protective reflex (stapedius reflex) in the middle ear is checked, from which conclusions are drawn about hearing ability and the origin of a hearing impairment. The stapedius reflex serves to protect our ears from noise. For measurement, a probe is inserted into the ear through which the latter is confronted with loudness. When the sounds are transmitted to the inner ear, there should be a muscle movement of the stapedius muscle. Consequence of this is again a movement of the eardrum, which can be represented as a curve. Due to lack of conduction, triggering of the stapedius reflex no longer occurs in cases of profound hearing loss or deafness.

Since 2009, standard screening for deafness has been performed as part of newborn screening. The goal here is to detect possible impairments as early as possible and to respond appropriately. In the screening, a measurement of otoacoustic emissions takes place. For this purpose, a small microphone is inserted into the ear, which can detect even very quiet echoes from the inner ear. Thus, the function of the cochlea can be checked. In Brain Electric Respone Audiometry, or BERA for short, it is also possible to detect a disturbance between the inner ear and the brain. For this purpose, brain waves are measured while tones or sounds are output via headphones.

In addition to imaging and determining hearing performance, blood tests help determine the cause of deafness. For example, infections or metabolic diseases can be identified as a conditioning factor. To shed light on the genetic basis of congenital deafness, additional investigations by other specialists, including neurologists, are informative.

Surdita's therapy

Surdita's is irreparable. That is, it cannot be cured, but secondary damage can be reduced and everyday life with hearing impairment can be improved for many. In cases of complete deafness, this can be solved with hearing implants. Often, this involves inserting a cochlear implant, but this is not suitable for all sufferers, nor is it desired by all. In the case of unilateral surditas, CROS hearing aids are a treatment option - these capture sound in the deafened ear and transfer it to the functioning one. Thus, there is improved hearing awareness of the environment, especially in noisy situations, group conversations, or driving sounds. Alternatively, strategies to deal with the deafness help, here is primarily the learning of sign language to attach, which significantly facilitates communication.