A determination of the acoustical input impedance characteristics of human ears

In a previous paper [2] the author described the difficulties associated with acoustical impedance measurements on real ears and developed a method for obtaining acceptable results. This paper describes the application of the method to the measurement of 48 normal hearing adult males at 15 frequencies within the range of 120 to 4000 c/s. Analysed results are given showing mean, standard deviation and 95% confidence limits for both the resistive and reactive components of the impedance. From these results “average” curves are deduced demonstrating the relatively complex relationship between the impedance and frequency. The reactive component of impedance is shown to exhibit an anomalous variation at low frequencies.