Low-frequency sound measuring equipment and wind noise reduction expansion method and wind noise reduction expansion unit

摘要

PROBLEM TO BE SOLVED: To reduce wind noise more.;SOLUTION: A low frequency sound measuring device includes: an outer microphone arranged outside a low frequency windshield; an inner microphone arranged inside the low frequency windshield; and a controller which processes output signals of the respective microphones, in which the controller has a management table in which a first reference value which is a measured value under a condition that a measurement object sound does not exist and shows a square effective value of wind noise by an output of the outer microphone, a second reference value which shows a square effective value of the remaining wind noise by an output of the inner microphone, and a third reference value which shows difference between both are recorded, calculates difference between an outer microphone output and an inner microphone output under a condition that the measurement object sound exists, refers to the management table on the basis of the calculated value, selects the second reference value corresponding to the calculated value from the management table when the calculated value matches to the third reference value, and calculates an effective true value which shows a square effective value of the measurement object sound from the difference between the outer microphone output and the selected second reference value.;COPYRIGHT: (C)2013,JPO&INPIT