Hearing loss is a common problem caused by noise, disease, aging, illness, and genetics. General signs of hearing loss occurs suddenly and develops gradually that includes asking people to repeat themselves, listening to music or television with a higher volume than required. There are two main types of hearing loss depending on where the problem lies they are conductive hearing loss, sensorineural hearing loss.
Sensorineural is caused by damage to the auditory nerve that occurs naturally with age. There are several options that help to improve a person’s ability to hear and communicate which includes digital hearing aids, cochlear implants, middle ear implants, bone anchored implants, wireless devices, etc. The 35delG mutation was detected in 11/ 712 unrelated blood donors.
Due to this, epidemiological studies could be carried out of the prevalence of occupational noise induced hearing loss in the total national economy throughout 1971--1979. Of the 35 mln Polish population, approx. 5 mln. 240 thous. persons are employed in industry, in this about 600 000 workers exposed to noise levels posing a risk of the hearing impairment of (Leq greater than or equal to 90 dB-A). It was found that occupational noise induced hearing loss was most frequent among all occupational diseases and its incidence rate exceeded 16 new cases annually per 100 000 employees.