| 摘要 |
PROBLEM TO BE SOLVED: To suppress variation of sound pressure of message sound according to frequency characteristics to output sound pressure of a speaker and allow a pedestrian to recognize vehicle speed feeling of a vehicle, without a processing circuit having high performance.SOLUTION: A microcomputer 21 comprises: a first sound production signal creation part 220a for changing frequency and output level of a first sound production signal Sa according to change of vehicle speed of a vehicle; and a second sound production signal creation part 220b for changing output level of a second sound production signal Sb according to change of the vehicle speed of the vehicle while maintaining frequency of the second sound production signal Sb constant. In addition, a mixer 23 is also provided for synthesizing the first and second sound production signals for creating a message sound signal. |
