There exist several types of hearing loss. Depending on the part of the auditory analyzer that has been affected, specialists differentiate conductive, sensorineural (or perceptive) and mixed hearing loss.
Conductive hearing loss is a hearing impairment caused by some kind of obstruction on the way of sound from the outer ear to the inner ear. Such condition can in most cases be helped by medical or surgical methods. Sometimes a doctor recommends using a hearing aid to correct the hearing loss. As in such cases the hearing aid serves only to amplify sounds, one of the simplest models may be chosen.
Sensorineural hearing loss is connected with a disorder in the transformation of sound vibrations into electric impulses conducted to the patient’s brain. Such hearing impairments are more complicated and difficult to treat. While conductive hearing loss manifests itself only in the lower volume of the perceived sounds, sensorineural hearing loss may also cause sound distortion. This kind of hearing loss can’t be corrected surgically. It can only be helped by using a hearing aid that allows fine-tuning in correspondence with the individual features of the patient’s condition.
Mixed hearing loss is a term used to denote a case of conductive hearing loss combined with the inadequate function of the inner ear. Such impairment, despite its complex origin and symptoms, can be also, in most cases, corrected by means of using a hearing aid.
Specialists also differentiate several degrees of hearing loss. To identify accurately the degree of hearing losspure tone audiometry (PTA) is used. That is a test in which the patient is offered sounds of different frequencies and intensity. Normally human ear detects sounds amplified to the level of less than 25 dB. The severity of hearing loss (from mild to profound) is measured by the degree of loudness sounds must reach to be detected by the patient. While a patient with a mild hearing loss is able to discern conversational speech from the distance of more than 4 meters, one with profound hearing loss can hear the same sounds only from the distance of less than 2 meters.
Various forms of hearing loss are differentiated according to the factor the illness was caused by. From this point of view two types of hearing loss are distinguished – hereditary and acquired.
Hereditary hearing loss may occur under the influence of various genetic factors, including the cases of birth defects. Some scientists single out as a separate group of hearing loss factors the non-genetic pathogenic influences affecting the ear of a foetus. This kind of influences, as well as hereditary illnesses, may result in hereditary hearing loss.
Acquired hearing loss is brought about by some influence on the auditory analyzer of a healthy individual. Acquired hearing loss may develop as the result of an injury or an infection. However, it may be caused by more trivial reasons, such as neglecting common sanitary rules and doctors’ advice. According to the scientists, in most cases hearing loss is brought about by a combination of factors influencing the patient’s organism in different periods of his life.
Hearing impairment can be diagnosed and effectively treated only if you have regular preventive examinations. As it becomes obvious from clinical experience, early detection of auditory impairments is the essential condition of their successful treatment. Preventive examinations should be taken at any age, starting from the very early. One should pay special attention to diagnosing hearing loss if there were cases of hearing loss in the family. The main measure helping to prevent hearing loss is avoiding risk factors. It’s absolutely necessary to treat conditions of upper air passages, carefully following the doctor’s prescriptions and trying to avoid complications. Keeping away from locations with noise and vibration exceeding permitted levels is also essential. People employed in hazardous industries must carefully observe safety measures.