What is noticeable deafness

Deafness, deafness: what is it?

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Last edited by Dr. rer. nat. Geraldine Nagel • Medical editor

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deafness is a hearing loss that can occur on one or both sides. Is only an ear deaf, impaired ability to determine the direction and distance of a sound source. are both ears deaf, lies one Deafness before: Then noises and tones are no longer perceptible.

In the case of deafness, the refers medical definition only on that Hearing ability. Doctors differentiate between absolute and practical deafness:

  • Absolute deafness means a hearing loss of more than 60 decibels (dB) in the range between 125 and 250 Hertz (Hz) and of more than 100 dB in the remaining frequency range.
  • Practical numbness means that there is a hearing loss between 85 and 100 dB. This so-called residual hearing loss or hearing loss bordering on deafness still enables the perception of individual tones or noises (so-called residual hearing).

In addition, defines the Community of the Deaf the deafness too linguistic and cultural identity: Accordingly, deaf people are hearing impaired who prefer to communicate in sign language and see themselves as part of this language community and its culture. Even those who are not affected by deafness themselves but have mastered sign language can see themselves as a member of this language community and culture.

Bilateral deafness can already exist at birth (innate Deafness or deafness) or develop only in the course of life (acquired Deafness). Depending on the point in time at which the hearing ability is lost, the following forms can be distinguished:

  • Prelingual deafness: Those affected are deaf before they can develop a language.
  • Postlingual deafness: The deafness on both sides only sets in after language development has taken place.

This division is important in terms of consequenceshaving a bilateral deafness for normal Language acquisition a child can have:

  • Does hearing loss do a child before the age of seven Deaf in both ears, this is usually associated with the complete loss of the language vocabulary acquired up to that point without countermeasures.
  • Deafness comes first after the age of seven one, the vocabulary is preserved.

A early unilateral deafness however, affects the child Not in his language development.


In the Federal Republic of Germany around 80,000 people are affected by bilateral deafness or deafness, which corresponds to a frequency of around 0.1 percent. Every year around 600 to 800 children are born deaf in Germany.


The connections between hearing and speaking have been known since the 17th century - and thus the possible consequences of deafness or deafness. This knowledge formed the prerequisite for Schools for the deaf to accomplish. The first school for the deaf was founded in Germany as an institution for the deaf and dumb in Berlin in 1788.