Pioneer Corporation

Tohoku Pioneer Corporation

Satoru Hiwatari

Hiroyuki Kobayashi

Hiroyuki Dohi

Koji Takayama

Takayuki Negishi

Provided is a sound generation device wherein noise can be reduced in accordance with a predetermined frequency band. An elastic member () is provided to obtain a sound pressure characteristic having a sub-peak at a predetermined frequency on the lower side than a lowest resonance frequency, and a phase characteristic such that a change rate of phase difference is lowered around the predetermined frequency. When the phase characteristic is calculated by simulation or actually measured in advance and an input signal is controlled such that the generated sound has an opposite phase to the noise, the generated sound can be made less prone to deviate from the opposite phase to the noise even if a time difference is caused between noise sound collection and sound generation at around the predetermined frequency, with the result that the noise can be effectively reduced. In addition, restrictions regarding the equivalent mass and resonance frequency of a diaphragm () can be reduced, the flexibility of design can be improved, and the noise can be reduced in accordance with the predetermined frequency band.

Sound generation device

A speaker unit emits a sound towards a box-like space formed by a vehicle. The speaker unit is accommodated in an enclosure. At least one of the enclosure and the speaker unit is provided with a tubular member and/or a vibration member configured to generate a resonance sound of a frequency different from a lowest resonance frequency of the speaker unit. At least a part of the enclosure also serves as a body of the vehicle.

Growing community of inventors

Yamagata, Japan

Satoru Hiwatari