Equalization for the dummy-head system

Abstract

In the dummy-head system, consisting of a dummy-head, head-phones, and a listener, an equalization method for precise reproduction of original sound is presented. We have three objects: (A) The quantitative expression of the sound pressure at the eardrum influenced by the human acoustic elements and the headphone. (B) The necessary equalization characteristics. (C) The realization of the equalizer irrespective of the direction of incident sound. In the analysis, the human acoustic system is divided into two parts at the ear canal entrance. Equivalent circuits for the listener's ear in the original sound field and for the one with headphones are derived. An expression of the necessary equalization characteristics for the listener is obtained in terms of elements of these equivalent circuits. The validity of the present method is verified by the experiment using a spherical head. Furthermore, variations between individuals about these elements should be investigated in order to make the precise reproduction for possibly many listeners.