Review of environmental factors affecting hearing.

Abstract

The major nongenetic causes of sensorineural hearing loss are exposure to noise, aging, ototoxic drugs, viral and bacterial infections, and interactions between these factors. Regarding exposure to continuous noise, the data base from laboratory and field studies indicates that a risk of hearing loss is present when noise levels exceed 75-80 dBA. As noise level, duration and number of exposures increase so does risk. The data base for other forms of noise (intermittent, impact) is not as established. Risk of hearing loss due to impulse noise increases as the peak SPL exceeds 145-155 dB and as the duration of the impulse, the number of impulses and the number of exposures increase. High-level acoustic impulses can cause severe, permanent hearing loss.

Higher Risk of Developing Sudden Sensorineural Hearing Loss in Patients With Chronic Otitis Media

“…Environmental factors that also lead to hearing loss may stem from differences in areas of residence of the COM-positive and COM-negative patients. 10 To treat these possible confounding factors, monthly income and area of residence of the patients were matched in the present study.…”

Effects of occupational exposure to organic solvents and noise on hearing.

“…Occupation al hearing loss has long been reco gnized as a direct health effect of overexpo sur e to nois e, but only recently has expo sure to solv ent s been con sidered as a contributor to the development of hearing impairment (4)(5)(6)(7)(8)(9)(10). There is evidence wh ich suggests that noise interact' > synerg istica lly with various drugs and chemicals (11)(12)(13)(14)(15)(16)(17)(18). Evidence is also beginning to accumulate which suggests that an ototra umatic interaction may ex ist between noise and org an ic sol-ve nts.…”

Sensorineural hearing loss: Potential therapies and gene targets for drug development

“…Exposure to continuous occupational and environmental noise levels in excess of 75 -80 dB is sufficient to pose a risk of hearing loss. The risk increases as noise level, duration and number of exposures increase (9,10). Noise can also interact synergistically with some ototoxic agents (each of which can cause hearing loss) including aminoglycoside antibiotics (e.g., streptomycin), loop diuretics (e.g., ethacrynic acid), antithyroid and antitumor drugs (e.g., cisplatin), excitatory amino acids (e.g., glutamate), or common antibiotics such as erythromycin and polymyxin B (9 -12).…”

“…Noise can also interact synergistically with some ototoxic agents (each of which can cause hearing loss) including aminoglycoside antibiotics (e.g., streptomycin), loop diuretics (e.g., ethacrynic acid), antithyroid and antitumor drugs (e.g., cisplatin), excitatory amino acids (e.g., glutamate), or common antibiotics such as erythromycin and polymyxin B (9 -12). Bacterial and viral infectious diseases such as measles, cytomegaloviral disease, pertussis, meningitis, and acute otitis media can also produce mild to severe hearing loss (9,11).…”