The measurement of audiometric zero level of air conduction

The audiometric zero level of air conduction for 100 healthy youths was determined over a frequency range from 20 Hz to 10 KHz in 1971-1973 under the laboratory conditions. The results obtained have been further verified recently on a selected group of 12 persons. This paper also presents the transfer experiments from the original earphone TDH-39(MX-41/AR) to six other types of earphones. The deviation of our data thus obtained from the recommendation by ISO is discussed.