Deafness: Information & deafness specialists

In Germany, around 0.1 percent of the population, approximately 80,000 people, are deaf. Deafness or deafness occurs when sounds and noises cannot be heard or can only be heard to a very limited extent. Although the sounds reach the ear in deaf people, the hearing organ cannot process or transmit them. Here you will find further information as well as selected specialists and centers for deafness.

Definition: Deafness

Deafness is the complete loss of hearing on both sides. In addition, medicine distinguishes between absolute deafness and practical deafness.

In the case of practical deafness, those affected can still perceive individual sounds or noises. In absolute deafness, on the other hand, there is no auditory impression at all.

Causes of deafness or deafness

Deafness can be congenital or acquired in the course of life due to illness. Congenital deafness, i.e. deafness that occurs before the development of the speech pathway, is referred to as pre-lingual deafness.

Severe congenital hearing impairment can be inherited or caused by influences during pregnancy.

Hereditary deafness is characterized by the fact that parts of the hearing organ such as

• the middle ear,
• the inner ear or
• the auditory nerve

are not or only incompletely developed. Children of deaf parents can then also be born deaf.

Many hereditary hearing impairments are associated with damage to other organs,

• such as the eyes,
• kidneys,
• bones,
• skin etc.

combined. Known syndromes with deafness include

• Usher syndrome with restriction of the field of vision or
• Waardenburg syndrome, in which pigment abnormalities occur in the skin, hair or eyes, and
• Alport syndrome,
• Jervell-Lange-Nielsen syndrome,
• Waardenburg syndrome,
• Cockayne syndrome and
• Pendred syndrome.

Some hearing impairments develop intrauterine, i.e. before birth during pregnancy. Severe intrauterine hearing loss is usually due to

• Infections with viruses such as rubella, cytomegaly or toxoplasmosis or
• bacteria such as lues

Toxic damage can be caused by

• Medication such as certain antibiotics, diuretics, cytostatics or
• poisons such as alcohol or nicotine

can be the cause.

Deafness can also occur perinatally, i.e. during birth. Risk factors are

• Premature birth,
• kernicterus or
• respiratory arrest with oxygen deficiency.

After birth(postnatal), acquired deafness can occur due to infectious brain diseases such as meningitis or encephalitis. Also

• infections such as mumps, zoster, measles, tuberculosis as well as chronic middle ear infections or
• toxic damage,
• serious accidents with skull fractures, in particular the petrous bone fracture

can cause deafness.

The inner structures of the ear © Henrie | AdobeStock

If the deafness only occurs after learning speech, it is referred to as post-lingual deafness. Causes are then

• Brain tumors,
• brain diseases such as multiple sclerosis,
• severe craniocerebral trauma,
• acoustic accidents such as explosions or barotraumas,
• severe infections, e.g. with herpes viruses,
• cytotoxins and drugs such as chemotherapeutics or loop diuretics, as well as
• antibiotics such as gentamycin.

In rare cases, there is psychogenic deafness in the sense of a dissociative hearing disorder. Genetically inherited tendencies to hearing loss are also known.

Symptoms of deafness or deafness

Deaf people cannot perceive any sounds or tones. Communication with the hearing and speaking environment is therefore difficult with unilateral deafness. In the case of bilateral deafness, those affected cannot learn speech and language or only with difficulty.

Deafness significantly impairs social contacts and career opportunities and often also leads to personality development disorders.

The first period of babbling also begins in deaf children from the 6th week to the 6th month. Without appropriate newborn hearing screening programs, the average age at which deafness is detected is more than two years.

In the case of congenital hearing loss, as mentioned above, damage to other organs such as

• eyes,
• bones,
• kidneys,
• skin

can occur.

Diagnosis of deafness or deafness

Deafness is diagnosed using special hearing tests. If deafness is suspected, a medical history is first taken with the patient or their parents. The doctor then carries out an ear, nose and throat examination.

The actual hearing tests are then, for example

• the tone audiogram, in which sounds of different frequencies are tested, or
• the Freiburg speech audiogram, in which numbers and words are tested.

In order to find the location of the functional loss, the following further tests are usually carried out:

• Measurement of otoacoustic emissions (OAE) for objective evidence of damage to the outer hair cells in the inner ear
• Objective hearing test such as BERA (Brainstem Evoked Response Audiometry) or CERA (Cortical Evoked Response Audiometry) to diagnose damage between the cochlea and the processing parts of the brain
• Balance testing to rule out involvement of the vestibular system
• Computed tomography (CT) and/or magnetic resonance imaging (MRI) to detect anatomical changes in the area of the cochlea or the auditory nerve
• Promontory test to check the functionality of the auditory nerve. This involves placing a small electrode through the eardrum directly onto the bone (promontory) and using electrical impulses instead of sounds. The affected person perceives these impulses as sounds.

OAE and ABR measurements, known as newborn hearing screening, are now standard for newborns and patients who are unwilling or unable to cooperate.

In newborn screening, the newborn's hearing ability is tested one or two days after birth. Any hearing disorders are detected early and can be treated.

Treatment of deafness

Deafness will not improve without appropriate therapy. In therapy, a distinction is made between conservative and surgical measures.

The aim of deafness therapy is to improve the patient's abilities in everyday life.

Causal therapy and surgery for deafness

Causal therapy is an option for acute deafness. This initially involves conservative treatments

• with antibiotics,
• infusions, e.g. with cortisone, as well as
• measures to promote blood circulation.

If these measures do not work, surgery is also an option. The middle ear is opened under either local or general anesthesia and the anatomical structures within it are checked for their function.

Hearing aids for deafness

If hearing does not improve, hearing aids are used. The hearing aids can be

• in the ear canal, i.e. largely invisible, or
• behind the ear

be worn behind the ear. Their function is to amplify incoming sounds and noises. Affected people can adapt the amplifier individually to the respective situation.

In rare cases, specially adapted hearing aids such as CROS hearing aids (Contralateral Routing Of Sound) are used if

• residual hearing is still present or
• deafness is only present in one ear.

CROS hearing aids can pick up the sound from the deaf side by routing the sound to the healthy side. In this way, they imitate directional hearing.

Cochlear implant for deafness

If the anatomical structures are intact, it is also possible to use a cochlear implant. In the case of severe bilateral hearing loss or complete deafness, the implant can replace the hearing function.

The cochlear implant consists of an inner and an outer part. The inner part with an electrode is implanted directly into the cochlea. The outer part is a microphone with a speech processor, which is worn on the outside of the head, usually behind the ear.

Cochlear implants should be inserted as early as possible so that children can achieve normal speech © satura_ | AdobeStock

The implant is powered by electromechanical induction through the scalp. The inner implant therefore does not require regular battery changes.

The external microphone picks up sound waves, which the speech processor converts into electrical impulses. The electrodes in the cochlea send these directly to the auditory nerve, which transmits the sound waves to the brain

The following requirements for a cochlear implant should be met:

• pre-, peri- and postnatally unilaterally or bilaterally deaf children with existing conductivity of the auditory nerve
• unilaterally or bilaterally deaf or profoundly deaf adolescents and adults
• Positive result in the promontory test if possible
• Sufficient anatomical prerequisites (cochlea or cochlear coil must be present)
• No serious underlying illnesses or recurrent inflammation
• Proven ability and willingness to learn in adults
• Guarantee of appropriate rehabilitation
• intact and motivated social environment

Brainstem implant in case of deafness

If there is damage to the auditory nerves, a brainstem implant is an option. Electrodes directly stimulate the auditory nerve nuclei in the brain.

The implantation is a neurosurgical procedure. Intensive rehabilitation in specialist centers is also required.

Other communication methods for deafness

If therapy is not possible, patients affected on both sides have to live with hearing loss. However, this does not mean having to do without communication completely.

Lip-reading and sign language help those affected to communicate with their environment.

Deaf people can communicate well using sign language and lip-reading © fizkes | AdobeStock

Healing prospects and aftercare

Early diagnosis and treatment has a positive effect on language development, particularly in the case of congenital or profound hearing loss.

Subsequent rehabilitation is crucial for the success of a cochlear implant. This is very extensive and is carried out in special centers, which are often referred to as CICs (Cochlear Implant Centers). Here, hearing and speech must be "relearned". Only constant training and appropriate motivation will lead to good results.

For children who are deaf from birth, the implants are inserted before the age of 1. The focus here is also on early intervention in the form of speech and language training. This enables them to acquire speech and language skills in the same way as healthy children. In many cases, those affected can then also attend a regular school.

For adults who are deaf, cochlear implantation is usually successful if

• the deafness has not persisted for too long,
• cognitive prerequisites are present and
• they have the motivation to learn to hear again.

Health insurance companies cover the costs of the operation and aftercare.