Alps Alpine Co., Ltd.

Alpine Electronics, Inc.

Blueprint Acoustics Pty Ltd

Continental Teves, Ag and Company Ohg

Keita Tanno

Ryosuke Tachi

Ryo Ito

Arata Tada

Haruki Uesugi

Mone Isami

Nozomu Saito

Noriyuki Toriyama

The sound processing device includes the first processor that performs the trans-aural process on the signals corresponding to the plurality of headrest speakers so that a tentative sound image is localized by the plurality of headrest speakers at a tentative position within a region which does not include the front side of the head but includes the left and right sides and the back side of the head, and the second processor that performs the amplitude panning on signals corresponding to the front speakers and a signal processed by the first processor so that a final sound image is localized at a final position between a tentative sound image and the front speakers in accordance with a difference in volume between the tentative sound image and the front speakers.

Sound processing device, sound system, and sound processing method

An active noise control system includes an error adder that generates an error signal by adding an output of a left-seat left microphone and an output of a left-seat right microphone, an adaptive filter that generates a noise canceling sound from a reference signal by performing an adaptive operation using the reference signal and the error signal, a left channel gain adjustment section that adjusts a gain of the noise canceling sound to be output to a left-seat left speaker, and a right channel gain adjustment section that adjusts a gain of the noise canceling sound to be output to the left-seat right speaker. A ratio between the gains of the left channel gain adjustment section and the right channel gain adjustment section matches a ratio between loudness levels of noise transmitted to the output of the left-seat left microphone and the output of the left-seat right microphone.

Active noise control system

A voice output from an i-th audio source apparatus is adjusted with a frequency transfer function W(f) set in an i-th noise reduction filter and is output from an i-th speaker. In the noise reduction filter, a frequency transfer function W(f) is set in which the sound is made smaller at frequencies where the gain of the frequency transfer function C(f) from the SPKi to a user tends to be relatively larger than the gain of the frequency transfer function C(f) from the SPKi to the user, and the sound is increased at frequencies where the gain of C(f) tends to be relatively smaller than the gain of C(f), where m is an integer excluding i from 1 to n.

Audio system

With respect to a noise reduction device using a speaker and a microphone corresponding to each seat in a vehicle to reduce a noise in each seat, the noise reduction device includes, a signal processing unit configured to generate a canceling sound that reduces a noise at an ear of an occupant in a predetermined seat by using an auxiliary filter, an operation setting unit configured to disable operations of a speaker and a microphone corresponding to each empty seat in the vehicle, and an auxiliary filter setting unit configured to change a setting value of the auxiliary filter used by the signal processing unit to generate the canceling sound in accordance with the number of occupants in seats other than the predetermined seat, the seats affecting the noise in the predetermined seat.

Noise reduction device, vehicle, noise reduction system, and noise reduction method

Forms of a vehicle loudspeaker system may include: a vehicle interior space defined on an inner side of a front windshield, a vehicle exterior storage space defined on a front side of the vehicle interior space such that a partition is disposed between the vehicle exterior storage space and the vehicle interior space, a cowl box disposed between an upper end of the partition and a lower end of the front windshield, and a loudspeaker including a diaphragm. The loudspeaker may be disposed in the cowl box such that sound pressure generated by the diaphragm is emitted to the vehicle interior space.

Growing community of inventors

Iwaki, Japan

Keita Tanno