[a Study on Acoustic Probe Audiometry by Means of a Nylon Bar with a Notched Head].

A nylon bar, with the head notched to make easy adequete contact with the short process of the malleus, was used for an acoustic probe. The first part of this paper deals with the acoustic properties of the nylon probe in comparison with those of a piano wire probe and a silver wire probe. The following results are obtained : (1) Clinically the most suitable length of the nylon probe was 8cm. (2) The nylon probe proved to be capable of transmitting undistorted wave forms of test pure tones at the intensity level necessary for clinical measurment at the frequencies of 500, 1000, 2000 and 4000cps. Amplitude of the output through the nylon probe was a linear function of the intensity of input signals. (3) The intensity of the output through the nylon probe was kept almost constant to the test signals of 500, 1000, 2000 and 4000cps, when the fixing pressure of the nylon probe was in the range between 0.02gr and ibgr.