What are the Most Common Causes of Hearing Loss?
It is probable that, when asked what causes hearing loss, the average individual would reply by saying that it is just an inevitable part of growing older. Yes, there is certainly truth in the assertion that auditory acuity has a tendency to deteriorate with age. However, this phenomenon, which is technically known as presbycusis, fails to account for the many other factors that contribute to varying degrees of deafness in subjects of all ages.
In essence, all sounds are the product of vibrations in the molecules contained in gasses such as air, liquids and solids. Our ability to detect these vibrations is provided by a series of anatomical structures within the ear that act sequentially to create a sensitive conductive pathway. Any permanent or temporary malfunction in one of these structures will result in some degree of impairment and so this is what causes the form of hearing loss known as conductive deafness.
Upon reaching the inner ear, these simple mechanical vibrations must be converted into more complex electrical impulses that, in turn, may be transmitted to the brain via the auditory nerve for interpretation. Damage to either the cochlea, the sensory apparatus responsible for the signal conversion, or to the auditory nerve, can give rise to the sensorineural form of deafness. In some cases both types of impairment may be present simultaneously and this results in the condition known as mixed deafness.
Regardless of the classification of impairment, the underlying reasons for the damage may vary quite widely and, in some cases, the symptoms may be only temporary. Acute infections of the outer or middle ear can lead to diminished conductivity and are what causes this temporary type of hearing loss in many subjects, particularly infants and young children. Such conditions will seldom require more than prompt treatment with an appropriate antibiotic in order to defeat the infection at which point normal auditory function will then be restored.
By contrast, repeated infections can eventually result in a chronic condition that may then carry the risk of permanent impairment unless detected and dealt with effectively. The treatment could involve surgery such as a tonsillectomy and, in the case of children, removal of the temporary adenoid tissue present just above the tonsils also. In other case the insertion of grommets can improve drainage by the Eustachian tubes sufficiently to eliminate or, at least, reduce the likelihood of repeated infections.
Perversely, treatment with antibiotics such as streptomycin and other common medications including aspirin and the anti-inflammatory ibuprofen can be what causes both temporary and permanent hearing loss. In the workplace, repeated exposure to solvents such as toluene or to styrene, both identified as having ototoxic properties may result in damage to the cochlea leading to sensorineural deafness.
More alarming, however, than the risks associated with these substances are those that can arise from sound itself. Repeated, prolonged exposure to noises in excess of 70 decibels may cause permanent impairment and most commonly affects a subject’s ability to detect sound at frequencies of 3,000, 4,000 or 6,000 Hertz. In the workplace, health and safety regulations require that all employees at risk be issued with ear defenders. Loud music from discos, car stereos and iPods is what, increasingly, is causing permanent hearing loss in young people.