| 摘要 |
PROBLEM TO BE SOLVED: To give "sound information useful for driving" by stereophonic sound to "only a driver" without using a headphone.SOLUTION: "Sound information useful for driving" is given to the right and left ears of a driver &bgr; seated on a driving seat α by "parametric speaker + binaural reproduction". When the driver &bgr; sits on the driving seat α, the right and left ear positions (ultrasonic wave irradiation positions) of the driver &bgr; are identified. Besides, a right speaker R1 and a left speaker L1 for ultrasonic wave generation are arranged above the driver &bgr;. Consequently, "a trouble caused by reproduction sound reproduced at the ears of the driver &bgr;" is prevented so as not to "allow persons on a front passenger seat and a back seat to hear the reproduction sound as direct sound or reflection sound" and the sound pressure difference of the reproduction sound with respect to the persons in the circumference is allowed to be larger. Thus, "sound information useful for driving" by stereophonic sound is given to "only the driver &bgr;" without using a headphone. |
