US 4,060,696 AGranted

Binaural four-channel stereophony

AssigneeVictor Company of Japan, Ltd.

InventorsMakoto Iwahara, Fumio Maruyama, Goro Fujiki, Toshinori Mori, Norio Hiyama, Mitsuru Kikuchi

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Abstract

A binaural four-channel stereophony comprises at least two dummy heads each provided with microphones at the ears of the dummy to pick up signals from various sound sources or groups of sound sources. The binaural signals representing each sound source or a group of sound sources are coupled to an acoustic crosstalk cancellation circuit and eventually applied to two front or two rear loudspeakers. Each sound source or group of sound sources is localized between adjacent ones of the four speakers to simulate the binaural effect produced in a closed-circuit type binaural sound reproducing system.

Claims11

Dependent claims

A four-channel stereophony using left and right front loudspeakers and left and right rear loudspeakers, comprising:

first and second dummy heads each simulating the human head in shape and dimensions and provided with left and right microphones mounted in positions corresponding to the ears of the human head to generate front binaural signals Lfs and Rfs from the first dummy head and second binaural signals Lrs and Rrs from the second dummy head;
means comprising a first crosstalk cancellation circuit connected to the microphones of the first dummy head for converting the first binaural signals into third binaural signals Lfsp and Rfsp such that said third binaural signals have the following relations to the first binaural signals:
##EQU12## where, T is a delay time, a.sub.11 and a.sub.12 are acoustic transmission characteristics over the path between the left front loudspeaker and the left and right ears, respectively, of a listener;
and
a.sub.21 and a.sub.22 are acoustic transmission characteristics over the path between the right front loudspeaker and the left and right ears, respectively, of the listener;
means comprising a second crosstalk cancellation circuit connected to the microphones of the second dummy head for converting the second binaural signals into fourth binaural signals Lrsp and Rrsp such that said fourth binaural signals have the following relations to the second binaural signals:
##EQU13## where, b.sub.11 and b.sub.21 are acoustic transmission characteristics over the path between the left rear loudspeaker and the left and right ears, respectively, of the listener;
and
b.sub.12 and b.sub.22 are acoustic transmission characteristics over the path between the right rear loudspeaker and the left and right ears, respectively, of the listener;
and
four-channel transducing means connected to the outputs from the first and second crosstalk cancellation circuit for translating the third and fourth binaural signals into reproduceable form;
whereby said third and fourth binaural signal, when electroacoustically reproduced, will produce front and rear binaural effects, respectively, to said listener.

9 more elements

A four-channel stereophony using two front and two rear loudspeakers, comprising:

first, second and third dummy head each simulating the human head in shape and dimensions and provided with microphones mounted in positions corresponding to the right and left ears of the human head to pick up front, lateral and rear sound sources, respectively;
a first crosstalk cancellation circuit connected to the microphones of the first and second dummy heads to generate first binaural signals which when electroacoustically reproduced through said front loudspeakers will produce a front binaural effect to a listener positioned in the sound field of said front and rear loudspeakers;
a second crosstalk cancellation circuit connected to the microphones of the second and third dummy heads to generate second binaural signals which when electroacoustically reproduced through said rear loudspeakers will produce a rear binural effect to said listener;
variable attenuators each connected between the microphones of the second dummy head and the first and second crosstalk cancellation circuits to provide adjustment of the signals applied to the first and second cancellation circuits relative to each other;
and
four-channel transducing means connected to the outputs from the first and second crosstalk cancellation circuits for transducing the first and second binaural signals in reproduceable form.

3 more elements

Dependencies are inferred from the claim text.

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Abstract

A four-channel stereophony using left and right front loudspeakers and left and right rear loudspeakers, comprising:

first and second dummy heads each simulating the human head in shape and dimensions and provided with left and right microphones mounted in positions corresponding to the ears of the human head to generate front binaural signals Lfs and Rfs from the first dummy head and second binaural signals Lrs and Rrs from the second dummy head;
means comprising a first crosstalk cancellation circuit connected to the microphones of the first dummy head for converting the first binaural signals into third binaural signals Lfsp and Rfsp such that said third binaural signals have the following relations to the first binaural signals:
##EQU12## where, T is a delay time, a.sub.11 and a.sub.12 are acoustic transmission characteristics over the path between the left front loudspeaker and the left and right ears, respectively, of a listener;
and
a.sub.21 and a.sub.22 are acoustic transmission characteristics over the path between the right front loudspeaker and the left and right ears, respectively, of the listener;
means comprising a second crosstalk cancellation circuit connected to the microphones of the second dummy head for converting the second binaural signals into fourth binaural signals Lrsp and Rrsp such that said fourth binaural signals have the following relations to the second binaural signals:
##EQU13## where, b.sub.11 and b.sub.21 are acoustic transmission characteristics over the path between the left rear loudspeaker and the left and right ears, respectively, of the listener;
and
b.sub.12 and b.sub.22 are acoustic transmission characteristics over the path between the right rear loudspeaker and the left and right ears, respectively, of the listener;
and
four-channel transducing means connected to the outputs from the first and second crosstalk cancellation circuit for translating the third and fourth binaural signals into reproduceable form;
whereby said third and fourth binaural signal, when electroacoustically reproduced, will produce front and rear binaural effects, respectively, to said listener.

9 more elements