Otosclerosis is characterized by abnormal bone deposition at the footplate (base of stapes). This bone deposition leads to fixation of the stapes at the oval window, preventing normal vibration. Otosclerosis typically presents as progressive bilateral conductive hearing loss in middle-aged white women. It is the leading cause of conductive hearing loss in adults who do not have a middle ear effusion or a history of otitis media. 10 There is usually a positive family history. Treatment consists of amplification with hearing aids or surgical repair by stapedectomy ( Figure 4 ) .
In the United States, the Occupational Safety and Health Administration (OSHA) describes standards for occupational noise exposure in articles and . OSHA states that an employer must implement hearing conservation programs for employees if the noise level of the workplace is equal to or above 85 dB(A) for an averaged eight-hour time period.  OSHA also states that "exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level".  The National Institute for Occupational Safety and Health (NIOSH) recommends that all worker exposures to noise should be controlled below a level equivalent to 85 dBA for eight hours to minimize occupational noise induced hearing loss. NIOSH also recommends a 3 dBA exchange rate so that every increase by 3 dBA doubles the amount of the noise and halves the recommended amount of exposure time.  The United States Department of Defense (DoD) instruction 605512 has some differences from OSHA standard, for example, OSHA uses a 5 dB exchange rate and DoD instruction 605512 uses a 3 dB exchange rate.
Treatment usually involves surgical removal of the tumor. However, if the tumor is small and asymptomatic, the patient and doctor may opt to monitor the tumor. This is also the case if the patient is not a good candidate for surgery such as elderly patients who have a history of heart and lung disease. The surgical excision of the tumor carries several risks including the risk that the nerves surrounding the tumor may be damaged. This is particularly true if the tumor is very large. Other options for treatment involve radiation therapy or radiosurgery. Both of these treatments are aimed at reducing the size of the tumor.