SA 50 is a hand held and battery operated audiometer, designed for basic screening purposes. SA 50 is easy to use and measures four frequencies at four different levels of air conducted pure tone stimuli. The result from SA50 gives you a fast and good indication of a potential hearing loss. SA 50 uses original audiometric TDH 39 earphones. Screening Search for hearing losses above certain predetermined level at different frequencies. Result: pass or fail