Hearing Loss - A growing problem that affects quality of life
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In this article, the term hearing loss, used by itself, denotes any or all levels of severity of hearing difficulty. These levels of hearing impairment comprise mild HL (26-40 decibel hearing level, dB), moderate HL (41-60 dB), severe HL (61-80 dB),
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and profound HL (81 dB or greater)1. Hearing loss is the most frequent sensory deficit in human populations, affecting more than 255 million people2,3 in the world (2002). Consequences of hearing impairment include inability to interpret speech sounds,
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often producing a reduced ability to communicate, delay in language acquisition, economic and educational disadvantage, social isolation and stigmatization2.
Most congenital and childhood onset hearing loss is included as sequel to various disease and injury causes already included in the Global Burden of Disease Study. Examples include otitis media, meningitis, rubella, congenital anomalies and non-syndromal inherited hearing loss2.
Those 192 million people with adult-onset loss (age 20 years and above) and 63 million people with childhood-onset loss make up almost 4.1 percent of the world's population and just over 40 percent of all people globally with hearing loss of any severity. Numbers with childhood-onset hearing loss by cause have so far not been estimated separately but are included among sequel of other diseases (for example, infectious diseases such as meningitis, otitis media, congenital conditions).
Causes and Characteristics
Hearing loss is grouped according to International Classification of Diseases and Related Health Problems, 10th revision, version for 2003 (ICD-10) into conductive and Sensorineural loss and other hearing loss, ICD-10 codes 90-91(WHO 2003).
Chronic otitis media (COM) includes chronic suppurative otitis media and otitis media with effusion. These forms of otitis media, together with some other middle ear diseases, such as perforation of the tympanic membrane, cholesteatoma, and otosclerosis, are the major causes of conductive hearing loss1.
Conductive hearing loss is caused by anything that interferes with the transmission of sound from the outer to the inner ear. Below are some possible causes of conductive hearing loss.
„« Middle ear infections (otitis media).
„« Collection of fluid in the middle ear (
