Apparatus for expanding and controlling sound fields

United States Patent im

Yamato et al.

■■Illllllllllll

US005710818A [li] Patent Number: [45] Date of Patent:

5,710,818 Jan. 20, 1998

[54] APPARATUS FOR EXPANDING AND CONTROLLING SOUND FIELDS

[75] Inventors: Tosbitaka Yamato; Hiroshi Kowaki. both of Kobe; Kazuya Sako. Kakogawa; Hiroyuki Yamaguchi, Kobe, all of Japan

[73] Assignee; Fujitsu Ten Limited, Hyogo-ken, Japan

[21] Appl. No.: 188,738
[22] Filed: Jan. 31, 1994

Related U.S. Application Data

[63] Continuation of Ser. No. 786,847, Nov. 1,1991, abandoned.

[30] Foreign Application Priority Data

Nov. 1, 1990 [JP] lapan 2-115813 U

Nov. 1,1990 [JP] Japan 2-115814 U

Nov. 8, 1990 [JP] Japan 2-305707

[51] Int CI.6 H04S 1/00

[52] U.S. CI 381/1; 381/86

[58] Field of Search 381/1, 63, 86

[56] References Cited

U.S. PATENT DOCUMENTS

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FOREIGN PATENT DOCUMENTS

0 160 431 Bl 4/1985 European Pat. Off. . 0 276 948 A2 1/1988 European Pat. Off. .

As in a compartment of an automotive vehicle, when a leftand a right-channel loudspeakers are disposed at angularly different positions from each other with respect to a frontward direction of a listening position, there will be formed a sound field laterally asymmetric with respect to the frontward direction of the listening position. In order to correct the asymmetry of the sound field, a crosstalk signal obtained by correcting the phase and the level of an acoustic signal of the left-channel from an acoustic signal source and a crosstalk adjustment signal obtained by correcting the level of the acoustic signal of the left-channel are fed to the right loudspeaker, or a center loudspeaker disposed between the left and right loudspeakers, together with an acoustic signal of the right-channel from the acoustic signal source. Similarly, a crosstalk signal obtained by correcting the phase and the level of an acoustic signal of the right-channel and a crosstalk adjustment signal obtained by correcting the level of the acoustic signal of the right-channel are fed to the left or center loudspeaker together with the acoustic signal of the left-channel from the acoustic signal source.

13 Claims, 16 Drawing Sheets