JP3073065B2 - Sound reproduction device having sound field correction function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio reproducing apparatus having a sound field correcting function, and more particularly to an apparatus which can be suitably used for a vehicle.

[0002]

2. Description of the Related Art A typical prior art is disclosed in Japanese Patent Application Laid-Open No. Hei 2-7699 filed by the present applicant, and is simplified and shown in FIG. In a vehicle cabin, a direct sound DR from the main speaker 1 is incident on a right ear ER of a listener 2 such as a driver. Following the path indicated by the broken line from the speaker 1, the sound RR reflected on the wall surface 3 such as a window glass also enters the right ear ER. An auxiliary speaker 4 is provided in the headrest of the listener 2, and the direct sound HRa incident on the right ear ER from the auxiliary speaker 4 has the same sound pressure level as that of the reflected sound RR and is in opposite phase to interfere with each other. I do. Thus, the reflected sound RR is canceled and canceled by the direct sound HRa from the auxiliary speaker 4. The auxiliary speaker 5 directed to the left ear EL of the listener 2 also has its left ear EL.
Generates sound that cancels the reflected sound that is incident on.

[0003]

In the prior art shown in FIG. 4, since the auxiliary speakers 4 and 5 are directed to the listener 2, the sound from the right auxiliary speaker 4 is transmitted to the listener 2. There is a problem that the sound reaches the left ear EL and the sound from the left auxiliary speaker 5 reaches the right ear ER of the listener 2, so that a desired sound field cannot be obtained accurately.

Further, in this prior art, the region where the reflected sound RR and the direct sound HRa from the auxiliary speaker 4 interfere with each other to cancel out the reflected sound RR is narrow, and therefore the right ear ER
In addition, even if the position of the listener 2 is slightly shifted, the reflected sound RR cannot be canceled by the direct sound HRa of the auxiliary speaker 4. The same applies to the other auxiliary speaker 5.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sound reproducing apparatus having a sound field correcting function capable of reliably canceling a reflected sound and widening an area where the reflected sound can be canceled. To provide.

[0006]

According to the present invention, there is provided a sound field comprising only a main speaker and a sound which is reflected by a reflecting object from the main speaker and propagates to a listener's ear on a reflecting object side at a listening position. A canceling sound signal generating means having a transfer function which is an inverse function of the function, and an acoustic signal to be supplied to the main speaker is input, and an output from the canceling acoustic signal generating means is provided, and An acoustic reproduction device having a sound field correction function, comprising: an auxiliary speaker provided near an ear and having a front axis inclined toward the reflective object.

[0007] The present invention also provides a left main speaker provided to the front left of the listening position and to which a left acoustic signal is applied, and a right main speaker provided to the front right of the listening position and to which a right acoustic signal is applied. And a left auxiliary speaker that is provided to the left near the listening position and has a front axis inclined toward the left reflective object, and a left auxiliary speaker that is provided to the right near the listening position and has a front axis near the right reflective object. A transfer which is an inverse function of a transfer function of a sound field composed only of a tilted right auxiliary speaker and a sound reflected from a right main speaker on a left reflecting object and propagated to a left ear of a listener at a listening position. A first canceling sound signal generating means which has a function and receives a right sound signal and supplies an output to a left auxiliary speaker; and a listener at a listening position reflected by a right reflecting object from a left main speaker. Of the sound field consisting only of sound propagating to the right ear of And a second canceling sound signal generating means having a transfer function that is an inverse function of the reaching function, receiving the left sound signal, and providing an output to the right auxiliary speaker. It is a sound reproducing device having:

[0008]

According to the present invention, the auxiliary speaker is provided in the vicinity of the ear of the listener at the listening position, and has a front axis inclined toward the reflective object. A sound signal to be supplied to the main speaker to a canceling sound signal generating means having a transfer function that is an inverse function of a transfer function of a sound field composed only of sound propagating to the listener's ear on the listener's reflecting object side Is output from the cancellation sound signal generating means, which is obtained when is input, and the sound output from the auxiliary speaker can cancel the sound by the main speaker reflected from the reflecting object.

In this way, direct sound from an auxiliary speaker provided near the listener's right ear, for example, is prevented from entering the left ear opposite to the listener, or near the listener's left ear. Is prevented from being incident on the right ear of the listener, so that a desired sound field can be obtained.

Further, according to the present invention, the front axis of the auxiliary speaker is inclined toward the reflecting object, and the front axis is not set toward the listener's ear. It is possible to widen the area where the sound reflected by the object is canceled. Therefore, even if the listener's head position, that is, the ear position is shifted, the reflected sound can be reliably canceled by the auxiliary speaker, and the area where a desired sound field can be obtained can be widened.

According to the present invention, main speakers are provided at the front and left of the listening position, and auxiliary speakers are provided at the left and right in the vicinity of the listening position. The right and left sound signals are input to the first and second canceling sound signal generating means, and the respective outputs are output to the left and right auxiliary speakers, respectively. The transfer functions of the first and second canceling sound signal generating means are reflected by the left and right reflecting objects from the right and left main speakers, respectively, and reflected on the left and right ears of the listener at the listening position. This is the inverse of the transfer function of each sound field consisting only of sound propagating to the left and right auxiliary speakers. So that each Re is canceled Re.

[0012]

FIG. 1 is a simplified plan view showing the entire structure of an embodiment of the present invention. Cab 7 of car 6
Are provided with seats 8 and 9 as listening positions, which are a driver's seat and a passenger seat, and main speakers F
L and FR are respectively attached. To these main speakers FL and FR, a left sound signal is supplied from a sound signal source 10 via a line 11, a right sound signal is supplied via a line 12, and further via amplification circuits 13 and 14.
Auxiliary speakers HR, HL are provided in headrests 8a, 9a of seats 8, 9, respectively.

FIG. 2 is an enlarged plan view showing the vicinity of the seat 8. The sound from the left main speaker FL is propagated to the window plate 15 which is a reflective object such as a plate-shaped window glass provided on the right door of the automobile 6 as indicated by reference numeral 16 and the window plate 15 The light 15 is reflected by the reference numeral 15 and enters the right ear ER2 of the driver who is the listener sitting on the seat 8. In order to cancel the reflected sound 17, the auxiliary speaker HR has a front axis 18 inclined toward the window plate 15 and an angle θ with respect to the front direction 19 of the sound field.
Having. The angle θ is selected, for example, as shown in Expression 1.

[0014]

0 ° ≦ θ ≦ 45 ° If the angle θ is too large, the sound from the auxiliary speaker HR may be reflected by the window plate 15 and the reflected sound may be incident on the right ear ER2. The angle θ is selected as shown in Expression 1 so that the sound reflected from the window panel 15 of the sound from the auxiliary speaker HR does not enter the right ear ER2. Auxiliary speaker H provided on the headrest 9a of the passenger seat 9
L is also provided symmetrically with the auxiliary speaker HR,
5 cancels the reflected sound of the sound from the main speaker FR.

The left acoustic signal passes through a second canceling acoustic signal generating means 20 from a line 11 and its output is supplied to an amplifying circuit 2.
1 and supplied to the right auxiliary speaker HR. The right acoustic signal is supplied from the line 12 to another first canceling acoustic signal generating means 22, the output of which is amplified by the amplifier circuit 23 and supplied to the left auxiliary speaker HL.

Referring to FIG. 3, the direct sound from the left main speaker FL is shown in FIG. 3 (1) to the left ear EL2 of the listener in the driver's seat 8 as indicated by reference numeral 24 in FIG. Incident at a given sound pressure level. The direct sound from the left main speaker FL is also incident on the right ear ER2 of the listener as shown by the sound pressure level 25 in FIG. Further, the direct sound 16 from the left main speaker FL is reflected by the window plate 15, and the reflected sound 17 is the sound pressure level 2 shown in FIG.
As shown by 6, the light is incident on the right ear ER2. In this embodiment, in order to cancel the sound of the reflected sound 17, the second canceling sound signal generating means 20 reflects the light from the left main speaker FL on the window plate 15 and reflects the sound from the left main speaker FL on the window plate 15 side of the driver's seat 8. It has a transfer function that is the inverse function 1 / HL1 of the transfer function HL1 of the sound field composed only of the sounds 16 and 17 that propagate to the right ear ER2 of the listener. As a result, the sound from the auxiliary speaker HR cancels the reflected sound 17, and therefore, the reflected sound 17 is prevented from entering the right ear ER.

The auxiliary speaker HR is provided near the right ear ER2 of the listener on the window plate 15 side, and the front axis is inclined by the angle θ near the window plate 15, so that the auxiliary speaker HR is directly transmitted from the auxiliary speaker HR. Sound is prevented from being incident on the right ear ER2 and the left ear EL2, thereby ensuring a desired sound field. Moreover, this auxiliary speaker HR
As described above, the front shaft 18 is inclined toward the window plate 15 as described above, so that the area where the reflected sound 17 can be canceled out is wide. Therefore, the listener's head and ears ER2, EL
Even if the position 2 is displaced, the reflected sound 17 can be reliably canceled to obtain a desired sound field. The same applies to the listener in the passenger seat 9. The first canceling sound signal generating means 22 transmits a sound field composed only of the sound reflected from the main speaker FR on the window plate 28 and propagated to the left ear EL1 of the listener on the window plate 28 side of the passenger seat 9. It has a transfer function that is the inverse function 1 / HR1 of the function HR1. Right main speaker FR
Sound 27 is reflected by a window 28 which is a reflective object such as a plate-like window glass, and the reflected sound 29 is canceled by a sound 30 from the left auxiliary speaker HL. Direct sound from the left main speaker FL is incident on the left ear EL2 in the driver's seat 8, and direct sound from the right main speaker FR is incident on the right ear ER1 in the passenger seat 9.

The present invention can be implemented in a wide range in relation to a sound field space in which other reflective objects are present, as well as for use in a vehicle.

As another embodiment of the present invention, the main speaker F
L, auxiliary speaker HR, and their associated amplifier circuit 1
3, 21 and only one canceling sound signal generating means 20 are provided, and even when the main speaker FR, the auxiliary speaker HL, and the like are omitted, the adverse effect of the reflected sound 17 can be prevented, and the present invention is implemented. be able to.

[0020]

As described above, according to the present invention, the auxiliary speaker is provided near the ear of the listener at the listening position on the reflecting object side, and the front axis of the auxiliary speaker is inclined toward the reflecting object. The auxiliary speaker has a transfer function that is an inverse function of a transfer function of a sound field composed only of sound that is reflected by the reflecting object from the main speaker and propagates to the listener's ear on the reflecting object side at the listening position, Since the acoustic signal to be supplied to the main speaker is input, not only can the reflected sound of the main speaker be canceled by the reflecting object, but also the direct sound from the auxiliary speaker can be transmitted to the ear on the reflecting object side. In addition, it is possible to prevent light from being incident on the opposite ear, and it is possible to obtain a desired sound field. Further, the front axis of the auxiliary speaker is inclined toward the reflective object as described above, i.e., when sound is generated from the auxiliary speaker when canceling toward the reflective object, the listener's head, and hence Even if the ear position is shifted, the desired sound field can be obtained because the area where the reflected sound is canceled out is wide.

Further, according to the present invention, for example, main speakers are provided on the left and right in front of a listening position such as a driver's seat and / or a passenger's seat in an automobile, and auxiliary speakers are provided on the left and right near the listening position. The front axes of these left and right auxiliary speakers are inclined toward a reflecting object such as a left and right window glass, respectively.
The first and second canceling sound signal generating means receive right and left sound signals, and outputs are respectively provided to left and right auxiliary speakers. The transfer function is the inverse of the transfer function of each sound field consisting of only the sound reflected from each of the left and right reflecting objects from the right and left main speakers and propagated to the left and right ears of the listener at the listening position. Function, so that the sound reflected by each reflecting object can be canceled.

[Brief description of the drawings]

FIG. 1 is a simplified system diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is an enlarged plan view near a driver's seat 8;

FIG. 3 is a diagram showing a listening state of the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a simplified plan view of the prior art.

[Explanation of symbols]

 Reference Signs List 6 automobile 7 cabin 8 driver's seat 9 passenger's seat 10 sound signal generating source 13, 14, 21, 23 amplifying circuit 15, 28 window plate 20, 22 canceling sound signal generating means FR, FL main speaker HR, HL auxiliary speaker

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04S 1/00 G10K 11/178 H04R 3/12 H04R 5/02 B60R 11/02

Claims (2)

(57) [Claims] 1. A transfer function that is an inverse function of a transfer function of a sound field composed only of a main speaker and a sound reflected from a main speaker by a reflecting object and propagated to a listener's ear on a reflecting object side at a listening position. A canceling sound signal generating means for inputting a sound signal to be provided to the main speaker; and an output from the canceling sound signal generating means, provided near the ear of a listener at a listening position, wherein the reflection is provided. An audio reproducing apparatus having a sound field correction function, comprising: an auxiliary speaker having a front axis inclined toward an object. 2. A left main speaker provided to the front left of the listening position and provided with a left acoustic signal; a right main speaker provided to the front right of the listening position and provided with a right acoustic signal; A left auxiliary speaker that is provided to the left near the position and tilts the front axis toward the left reflective object, and a left auxiliary speaker that is provided to the right near the listening position and tilts the front axis toward the right reflective object It has a right auxiliary speaker and a transfer function that is the inverse function of the transfer function of the sound field consisting of only the sound that is reflected from the right main speaker on the left reflecting object and propagates to the left ear of the listener at the listening position. The first audio signal is input and the output is given to the left auxiliary speaker.
A canceling sound signal generating means, and a transfer function which is an inverse function of a transfer function of a sound field composed only of sound reflected from a left main speaker by a right reflecting object and propagated to a right ear of a listener at a listening position. A second audio signal having a function, the left acoustic signal being input, and the output being provided to the right auxiliary speaker.
A sound reproducing apparatus having a sound field correcting function, comprising a canceling sound signal generating means.