1486827 Audiometers GLOWNY INSTYTUT GORNICTWA 6 Sept 1974 [12 Sept 1973] 38940/74 Heading G5J An audiometer for testing hearing comprises a variable frequency oscillator 2 connected by a variable gain control 4 and amplifier 5 to earphones 7, both the oscillator and gain control being controlled by a solid state control unit 8 to provide desired combinations of frequency and intensity. By thus avoiding the use of contact making switches the introduction of static noise is prevented. The combinations of frequency and intensity may be automatically selected according to a program.
