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

Abstract: 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.

Abstract: 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.

Abstract: A sound output by an i-th audio source device is adjusted by an i-th sound leakage reduction filter with a frequency transfer function set in the i-th sound leakage reduction filter and is output from an i-th speaker toward a user. The frequency transfer function relatively reduces the volume of the sound at a frequency where a first gain of a frequency transfer function from the speaker to one or multiple predetermined sound leakage reference positions outside the vehicle tends to be high relative to a second gain of a frequency transfer function from the speaker to the user, and relatively increases the volume of the sound at a frequency where the first gain tends to be low relative to the second gain.

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

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.