Hearing loss

A number of different factors affect the risk of hearing loss associated with exposure to excessive noise. The most important of these are  

Of these various factors, the most critical are the sound level, frequency, duration, and distribution of noise. The unprotected human ear is at risk when exposed to sound levels exceeding 115 dBA. Exposure to sound levels below 80 dBA is generally considered safe. Prolonged exposure to noise levels higher than 80 dBA should be protected against through the use of appropriate personal protective devices. 

To decrease the risk of hearing loss, exposure to noise should be limited to a maximum eight-hour time-weighted average of 90 dBA. Some general rules for dealing with noise in the workplace are  

Lomax et al. (2000) explored the potential for microarrays to investigate the involvement of genes in the recovery of hearing loss following noise frauma. The chick basilar papilla model was used. Noise exposure is known to cause the loss of hair cells in the basilar papilla. However, birds have the ability to regenerate these hair cells on the auditory epithelium and thus serve as useful models for sfudying hearing loss and recovery. 

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Ototoxicity, as evidenced by transient or permanent hearing loss, is a serious side effect of ethacrynic acid, and occurs less frequently with furosemide. Bumetanide is claimed to have only 20% of the ototoxic potential of furosemide (43). It has been reported that patients treated with torasemide at high doses for four weeks did not suffer hearing loss (36). 

Is there exeessive noise that may hinder eommunieation or is likely to eause hearing loss ... 

Hear loss through back side, appr. 10%... 

Conductive hearing loss Hearing loss that is caused by blockage or other interference in the path by which sound energy is transferred to the inner ear. 

Nosocusis Hearing loss resulting from causes other than noise, such as disease, heredity, etc. 

Sensory hearing loss Irreversible hearing loss resulting from damage to the inner ear tissue that translates sound pressure into nerve impulses. 

Sociocusis Hearing loss that results from exposure to the noises of everyday life. 

Administration of the aminoglycosides with the cephalosporins may increase the risks of nephrotoxicity. When the aminoglycosides are administered with loop diuretics there is an increased risk of ototoxicity (irreversible hearing loss). There is an increased risk of neuromuscular blockage (paralysis of the respiratory muscles) if the aminoglycosides are given shortly after general anesthetics (neuromuscular junction blockers). 

Compounds containing mercury, particularly its organic compounds, are acutely poisonous. Mercury vapor is an insidious poison because its effect is cumulative. Frequent exposure to low levels of mercury vapor can allow mercury to accumulate in the body. The effects include impaired neurological function, hearing loss, and other ailments. 

HCMV is widespread in the human population. In immunocompetent individuals, the infection is inapparent or associated with mild symptoms. However, HCMV is frequently transmitted perinatally and is the leading cause of neurological disease and hearing loss in congenitally infected newborns, affecting some 8,000 newborns per year in USA alone (Arvin and Alford 1990). Furthermore, following the first 100 days after transplantation, HCMV-induced pneumonia develops in about 50%... 

Salicylism, or salicylic acid toxicity, is characterized by rapid breathing, tinnitus, hearing loss, dizziness, abdominal cramps, and central nervous system reactions. It has been reported with 20% salicylic acid applied to 50% of the body surface, and it has also been reported with use of 40 and 50% salicylic acid paste preparations [7]. The author has peeled more than 1,000 patients with the current 20 and 30% marketed ethanol formulations and has observed no cases of salicylism. 

Sudden Hearing Loss Mullicenter Treatment Trial (SSNHL)... 

Rat (Long- Evans) 5 d 6 hr/d 2000 M 4000 M (postexposure mid-frequency hearing loss, sedation) Crofton and Zhao 1993... 

Crofton KM, Zhao X. 1993. Mid-frequency hearing loss in rats following inhalation exposure to trichloroethylene evidence from reflex modification audiometry. Neurotoxicol Teratol 15 413-423. 

Jaspers RM, Muijser H, Lammers JH, et al. 1993. Mid-frequency hearing loss and reduction of acoustic startle responding in rats following trichloroethylene exposure. Neurotoxicol Teratol 15 407-412. 

Auditory Sensorineural hearing loss due to sickling in cochlear vasculature with hair cell damage... 

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