A Hardware-Software Complex for Ipsilateral Measurements of the Acoustic Reflex Threshold

A hardware-software complex has been designed for ipsilateral measurements of the acoustic reflex by determining the resonant frequency of the external auditory canal, which changes due to an involuntary contraction of the middle-ear muscles in response to high-intensity sounds. A modified two-microphone method was used to determine the resonance characteristics of the external auditory canal. Measuring the sound pressure and the phase difference of acoustic vibrations in two cross sections of a waveguide, which is hermetically connected to the external auditory canal, allows determination of the necessary acoustic characteristics in a given frequency range. The software allows one to automatically generate a test polyharmonic signal and control the amplitude of a stimulating signal and, based on the results of processing the measured data, calculate the frequency-dependent reflection coefficients, absorption coefficients, and components of the acoustic impedance of the external auditory canal. The fundamental features of the complex are the absence of the need to create a stationary overpressure in the external auditory canal, as well as the provision of a direct measurement of the impedance of the external auditory canal in the audio-frequency range with any specified step.