| 摘要 |
PURPOSE:To evaluate correctly the sound fited in an automobile by arranging a dummy mannequin of actual human body constitution which haa surface sound absorbing force nearly equal to the mean sound absorbing force of a human wearing clothes at a specific listening point, and measuring acoustic transfer characteristics on the basis of outputs of microphone put in ear holes. CONSTITUTION:Noise generators 6-9 for driving speakers 1L and 1R, and 2L and 2R of four channels independently are provided and random noises, such as white noises, generated by those noise generators 6-9 are supplied as source signals to the speakers 1L and 1R, and 2L and through amplifiers 10-13. Output signals of microphones 3L and 3R in both ears of a dummy head 4 are added together by an adder 14 and supplied to an analyzer 15. Addition outputs of the adder 14 are averaged to obtain a sound reception output characteristics at the listening point, and acoustic transfer characteristic between speakers and the dummy head is measured from the difference between the sound pressure output characteristic and a transfer characteristic before a sound source. |
