Abstract: A portable precision automatic audiometer for testing hearing of an individual utilizes a voltage programmable oscillator in combination with a preprogrammed logic circuit to generate and transmit sweep frequency tones automatically or fixed frequency tones under manual control into a suitable earphone worn by the individual examinee being tested. A voltage proportional attenuator is controlled by an examinee manually operated switch and enables the examinee being tested to regulate the level of sound pressure to which he is being exposed, while a chart recording instrument simultaneously graphs the audiogram of his test responses. Improvements are provided with respect to noise reduction and ease of calibration.