Does lithotripsy cause hearing loss?

Abstract

OBJECTIVE: To determine whether lithotripsy with the Dornier MPL9000 has any significant effect on the hearing of either patients or operators, as determined by pure tone audiometry. PATIENTS AND METHODS: Twenty patients had audiometry prior to a single exposure to lithotripsy and one hour after treatment. Staff were monitored on a 3 monthly basis. RESULTS: No evidence was found to suggest that single or repeated exposure to the noise emitted by this Dornier lithotripter was associated with any hearing loss. CONCLUSIONS: These results suggest that the risk to the hearing of patients exposed to lithotripter noise is negligible. Cochlear damage resulting from excessive noise depends on both the intensity of the sound and the duration of exposure. The acoustic properties of the building housing the machine may also be important and can significantly influence the intensity of the sound at the ear. At marginal levels it may be years before the deficit reaches a level that can be detected by subjective audiometry. In addition, susceptibility to noise induced hearing loss is difficult to predict. Although these results suggest that there is minimal risk to the hearing of staff members exposed to lithotripter noise, the authors recommend that staff exposed to repeated lithotripter noise over long periods undergo regular audiometric assessment (including a preemployment baseline assessment) to identify evidence of noise induced auditory trauma, and that protective equipment be worn by staff members to reduce the possibility of long-term damage.