| 摘要 |
PURPOSE:To make the calculation of a transmission characteristic of a signal converting circuit excelelnt with a small circuit scale and to improve sound quality by obtaining the transmission characteristic of the signal converting circuit based on a measured transfer function and taking average of width corresponding to critical band width. CONSTITUTION:A pair of microphones ML and MR are arranged at the both ears of a dummy head DM, measurement sound from a speaker SP is received and lease sound refL, refR and sound to be measured L, R are synchronized and recorded in a recorder DAT. A prescribed processing is executed on a workstation through the use of the recording and the frequency response IR(S) of a measurement position HRTF is obtained. Then, average moving processing is performed by optimum band width in accordance with a frequency band and it is defined as the transmission characteristic of the signal converting circuit. The moving averaged discrete frequency response is reverse FET- converted and defined as the time response of a cancel filter. Then, a moving average is executed so that the convergence of time response is quickened, the transfer characteristic of the signal converting circuit is made well calculate with a small scale, a cost is reduced and sound quality is improved. |
