JP2003250192A - Loudspeaking unit and indoor loudspeaking system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loudspeaking unit and an indoor loudspeaking system capable of preventing the decline of clarity due to howling and echoes. <P>SOLUTION: When a speaking person S speaks, the speech sound reaches a microphone element 300 from a direction indicated by an arrow B and picked up by the microphone element 300. Then, the loud speech sound of the speaking person S is emitted from a speaker phone 104 toward the ceiling. Since a reflector 20 is provided between the speaker phone 104 and the microphone element 300, reflected sound reflected at the ceiling does not directly reach the microphone element 300. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker and an indoor loudspeaker system for loudspeaking voices and musical sounds.

[0002]

2. Description of the Related Art FIG. 21 is a diagram showing a structure of a conventional indoor loudspeaker system used in a room space such as a conference room. Further, FIG. 22 is a block diagram showing an electrical configuration of a conventional indoor loudspeaker system. As shown in FIG. 21, a proximity microphone M is installed near each speaker S. Each microphone M picks up the voice of the nearby speaker S. Further, as shown in FIG. 22, each microphone M outputs an electric signal corresponding to the collected sound to the mixing console MC. The mixing console MC combines the electric signals output from the microphones M and outputs the combined signals to the power amplifier PA.

More specifically, the mixing console MC is provided with an amplifier AMP and a switch SW for each microphone M. The amplifier AMP has a gain that can be set by the operator of the mixing console MC, amplifies the electric signal output from the microphone M according to the gain setting value, and outputs the amplified electric signal to the switch SW.
The switch SW can be turned on / off by an operator, and when it is on, outputs the electric signal output from the amplifier AMP to the mixer MX. The mixer MX is
The electric signals received from the amplifier AMP that is on are combined, and the combined electric signal is output to the power amplifier PA. A speakerphone SP is connected to the power amplifier PA. The power amplifier PA amplifies the electric signal received from the mixer MX and outputs it to the corresponding speakerphone SP. The speakerphone SP is installed in one corner of the conference room and emits a sound according to the received electric signal into the conference room. Further, the volume of the sound emitted from the speakerphone SP is increased according to the magnitude of the amplitude of the input electric signal.

In such a configuration, the operator of the mixing console MC sets the gain of the amplifier AMP to adjust the volume of the sound emitted from the speakerphone SP. Further, the operator turns on / off the switch SW for each speaker S, and sets the gain of the amplifier AMP corresponding to the microphone M of the speaker S to be audible. Is audible and speakerphone S
Sound is emitted from P into the conference room.

[0005]

As described above, in the conventional indoor loudspeaker system, the mixing console MC is used.
It is necessary for the operator to turn on / off the switch SW provided in the above and to adjust the gain setting of the amplifier AMP. If the operator does not properly set the gain of the amplifier AMP, the loud sound emitted from the speakerphone SP is picked up by the microphone M again, and is returned between the microphone 3, the mixing console MC, and the speakerphone SP. A loop is formed and one of the amplifiers AMP
If the gain of is excessively increased, there is a problem that howling and echo (extension of reverberation) deteriorate the clarity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a loudspeaker and an indoor loudspeaker system capable of preventing howling.

[0007]

In order to achieve the above object, the present invention provides a sound collecting means which is provided in a room space and which outputs an electric signal according to the collected sound, and the sound collecting means in the room space. A sound emitting unit that is provided and emits sound according to the electric signal,
Provided is a loudspeaker which is a plate member that reflects sound and includes a plate member that is sandwiched between the sound collecting unit and the sound emitting unit.
In the configuration of this loudspeaker, the sound collecting means outputs an electric signal according to the collected sound. Further, the sound emitting means emits a sound according to the electric signal output from the sound collecting means. Here, a plate member is provided so as to be sandwiched between the sound collecting means and the sound emitting means. That is, of the sound from the sound emitting means, most of the sound toward the sound collecting means is reflected by the plate material. As a result, of the sounds from the sound emitting means, the sound that returns to the sound collecting means is minimized, so howling is prevented.

In order to achieve the above object, the present invention provides a sound collecting means which is provided in a room space and which outputs an electric signal according to the collected sound, and a time range in which no echo occurs.
And, a signal delay means for giving a time delay such that a hearth effect is obtained for the listener to the electric signal and outputting the electric signal, and means for emitting a sound according to the electric signal output from the signal delay means, Provided is an indoor loudspeaker system including a sound emitting unit provided in the room space so that the sound collecting unit is not included in the sound emitting service zone. In the configuration of this indoor loudspeaker system, the sound collecting means outputs an electric signal according to the collected sound. Further, the signal delay means gives a time delay to the electric signal in a time range in which no echo is generated and a hearth effect is obtained for the listener, and outputs the electric signal. The sound emitting means emits a sound according to the electric signal from the signal delaying means. Here, the sound collecting means is provided at a position that is not included in the service zone of the sound emitting means. That is, the sound emitted from the sound emitting means hardly returns to the sound collecting means, and howling is prevented.
Further, according to this indoor loudspeaker system, the signal delay means gives a time delay to the electric signal within a time range where the echo does not occur and a Haas effect is obtained for the listener, so that the echo occurs. First, the hearth effect can be given to the listener, and the sound image localization can be maintained in the place where the sound source is located.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 is a diagram showing a mode of use of a loudspeaker according to a first embodiment of the present invention. Further, FIG. 2 is a cross-sectional view showing a schematic configuration of the loudspeaker.
As shown in FIG. 1, the loudspeaker 1 is arranged on a table such as a round table arranged in a room space such as a conference room. The loudspeaker 1 includes a parabolic reflector 20. The surface of the reflection plate 20 is covered with a sound-reflecting material such as a decorative copper plate, and the reflectance of sound on the surface is high. In addition, the reflector 20 is
With the concave side as the upper surface and the bulge side as the lower surface,
It is supported on the table by three legs 40. here,
The three legs 40 lift the respective positions from the lower side of the lower surface of the reflection plate 20 so as to have three vertices when an equilateral triangle is drawn with the lowermost part as the center.

A microphone 30 is provided at the bottom of the lower surface of the reflection plate 20. More specifically, as shown in FIG. 2, the microphone 30 includes a microphone element 300.
Is equipped with. The microphone element 300 has omnidirectional sound collection characteristics. Microphone element 300
Is covered and protected by a dome-shaped microphone cover 302 made of metal or the like.

On the other hand, a speaker portion 10 is provided at the center of the upper surface of the reflection plate 20. As shown in FIG. 2, the speaker unit 10 includes a speakerphone 104. The speakerphone 104 has a unidirectional directivity for sound emission, and is attached and fixed to the reflection plate 20 by the fixing legs 106 so that the directivity direction is directed upward in the drawing (indicated by an arrow A in the drawing). ing. The speakerphone 104 is covered with a dome-shaped speaker net 102 made of metal or the like. The edge of the speaker net 102 is a rubber vibration isolator 1.
It is attached to the reflection plate 20 via 08. The anti-vibration rubber 108 absorbs the vibration of the speaker net 102 caused by the sound emitted from the speakerphone 104, and prevents the reflector 20 from vibrating. As a result, noise generated by the vibration of the reflection plate 20 is prevented from being picked up by the microphone element 300.

Further, as shown in FIG. 2, the speakerphone 1
A signal processing unit 50 is provided below 04. Between the speakerphone 104 and the signal processing unit 50,
Also, the signal processing unit 50 and the microphone element 30.
Between 0, a signal cable such as a coaxial cable (not shown)
Are connected to each other by. FIG. 3 is a block diagram showing an electrical configuration of the signal processing unit 50 together with the microphone element 300 and the speakerphone 104. As shown in the figure, the microphone element 300 generates an electric signal according to the collected sound and outputs the electric signal to the signal processing unit 50 as a collected signal. The signal processing unit 50 includes an amplifier 502, and the amplifier 502 amplifies the sound pickup signal output from the microphone element 300 and outputs the amplified sound pickup signal to the delay circuit 504. The delay circuit 504 delays the received sound pickup signal by the time τe, and then the equalizer 5
It outputs to 06. The time τe will be described later in detail.

The equalizer 506 is a speakerphone 104.
After the sound pickup signal received from the delay circuit 504 is subjected to frequency decomposition and gain adjustment in the frequency domain is performed in order to make the sound color of the sound emitted from the sound sound closer to that of the live sound (voiced sound),
Output to the power amplifier 508. Power amplifier 508
The speakerphone 104 by amplifying the received sound pickup signal.
Output to. The speakerphone 104 emits a sound according to the received sound collection signal.

The echo canceller 520 outputs the loud sound emitted from the speakerphone 104 to the microphone element 300.
It is intended to prevent acoustic echo generated by returning to the. More specifically, the echo canceller 520
Includes an adaptive filter 522 and a subtractor 524.
In this adaptive filter 522, the impulse response characteristic is from the speakerphone 104 to the microphone element 30.
Adaptive control of the filter coefficient is performed so that the impulse response characteristic of the acoustic transmission system reaching 0 is obtained. If no measures are taken under this adaptive control, the speakerphone 1
04, the electric signal corresponding to the acoustic echo component that will reach the microphone element 300 from the adaptive filter 522.
Generated by the subtractor 524, and the electric signal is subtracted from the output signal of the amplifier 502. This operation prevents the generation of acoustic echo.

Now, as shown in FIG. 1, a large number of speakers S
Sits around the loudspeaker 1. When the speaker S utters, as shown by the arrow B in FIG.
While being guided by the reflection plate 20 and the desk, it travels through the gap between the reflection plate 20 and the desk, reaches the microphone 30, and is picked up by the microphone element 300. Microphone element 300
Is a signal processing unit 5 which collects a picked-up signal corresponding to the picked-up sound.
Output to 0.

In the signal processing unit 50, an echo canceller 520 subtracts an electric signal corresponding to an acoustic echo from the collected sound signal, and the collected sound signal is output to the delay circuit 504. Then, the picked-up signal is sent to the delay circuit 5
04 gives a time delay of time τ and equalizer 5
It is output to 06. Next, the collected sound signal is equalized by the equalizer 50.
After the gain of the frequency component is adjusted by 6, the signal is output to the power amplifier 508. The collected sound signal is amplified by the power amplifier 508, and then the speakerphone 1
It is output to 04. As a result, the loud sound of the speaker S is emitted from the speakerphone 104. As described above, the speakerphone 104 is in the direction indicated by the arrow A in the figure, that is,
A loud sound is emitted toward the ceiling. The emitted loud sound is reflected on the ceiling, and the reflected sound reaches the listener (speaker).

Further, in the loudspeaker 1, since the reflection plate 20 is provided between the speakerphone 104 and the microphone element 300, the reflected sound reflected on the ceiling reaches directly from above the microphone element 300. There is nothing to do. Therefore, among the loud sound, the microphone element 300 reaches the microphone element 300 from the direction shown by the arrow B in the figure after being guided by the reflector 20 and the desk after being multiple-reflected by the ceiling, floor, and side walls. There is only one. Generally, sound is reduced in sound pressure level when reflected by a wall surface or the like, so that sound pressure level of the sound that reaches the microphone element 300 due to multiple reflections among the loud sound is sufficiently low.

As described above, in the loudspeaker 1, the reflection plate 20 causes the sound emission space area of the speakerphone 104 to
The sound collection space area of the microphone element 300 is separated, and the loud sound from the speakerphone 104 does not reach the microphone element 300 while maintaining its sound pressure level. As a result, even if the amplification gain of the amplifier 502 or the power amplifier 508 is increased and the sound pressure level of the loud sound is increased, the sound pressure level of the loud sound reaching the microphone element 300 becomes sufficiently small.
Howling does not occur.

In the loudspeaker 1, the extension of the reverberation time caused by the return of the loud sound emitted from the speakerphone 104 to the microphone 30 is suppressed. Hereinafter, this point will be described. FIG. 4 is a diagram showing the relationship between the time when the uttered sound of the speaker S reaches the listener and the sound pressure level of the uttered sound that reaches the listener. FIG. 5 is a diagram showing an example of the relationship between the time when the loud sound from the speakerphone 104 reaches the listener and the sound pressure level of the loud sound that reaches the listener.

As shown in FIG. 4, at the place where the listener is, the reverberation sound R attenuated according to the reverberation attenuation characteristic p in the room space arrives after the utterance sound V of the speaker S arrives. Further, when the vocalization sound V of the speaker S is amplified using various devices, the loudness sound L emitted from the loudspeaker 1 is higher than the vocal sound V of the speaker S, as shown in FIG. After a delay of time τ, the sound is emitted from the speakerphone 104 and reaches the listener. After that, the reverberant sound of the loud sound L reaches the listener. Generally, when the loud sound L from the speaker returns to the microphone element, the sound pressure level of the reverberation sound R rises by the amount of the returned sound. Therefore, as shown in the reverberation attenuation characteristic q in FIG. The decay rate of becomes gentle and the reverberation time is extended. As a result, the reverberation time becomes long, and the clarity of the loud sound heard by the listener deteriorates.

On the other hand, according to the loudspeaker 1 of this embodiment,
Since the sound pressure level of the loud sound that returns to the microphone element 300 is sufficiently small, the increase in the sound pressure level of the reverberation sound R is suppressed, so that the reverberation attenuation characteristic p ′ is as shown in FIG. The characteristic is substantially the same as the reverberation attenuation characteristic p.
Therefore, since the reverberation time is not extended, the clarity of the loud sound heard by the listener does not deteriorate.

Further, in the present embodiment, as described above, the sound pickup signal output from the microphone element 300 is provided with the electrical delay τe by the delay circuit 504, and the uttered sound reaches the listener. A delay τs due to the difference between the spatial path of the speakerphone 104 and the spatial path of reaching the listener from the speakerphone 104 is added, so that at the time when the loud sound from the speakerphone 104 reaches the listener, the vocal sound of the speaker S reaches the listener. It is behind the time by about time τ (= τe + τs). Due to this delay of time τ, even if the direction of arrival of the loud sound to the listener is different from the direction of the direct sound, the listener feels as if the loud sound came from the direction of the direct sound ( Hearth effect (preceding sound effect). Therefore, in the loudspeaker 1, even if the sound pressure level of the loud sound is increased by the Haas effect, the sound image localization is
The position of the speaker S is maintained, and the listener feels as if the speaker S is speaking at the sound pressure level of the loud sound.

Here, it is desirable that the above-mentioned time τ is set to a value of about 10 ms to about 50 ms.
More specifically, as shown in FIG. 6, if the time τ is set to a value smaller than 10 ms, the listener feels strange in the tone color of the voice of the speaker S who has heard it. This is due to the so-called coloration, which is a change in timbre due to frequency interference between the loud sound and the vocal sound. Also, time τ is 5
When the value is set to be larger than 0 ms, so-called dubli (echo), in which the loud sound and the uttered sound are temporally separated, is noticeable to the listener, and the above-mentioned Haas effect cannot be obtained. It becomes difficult to hear the voice of the speaker S. That is, the time τ is set to a value within a time range in which no echo is generated for the listener and a hearth effect is obtained for the listener. Here, the electrical delay time τe is set to be approximately 10 ms <τe + τs <50 ms depending on the positional relationship among the speaker, the listener, and the speakerphone 104.

As described above, according to the first embodiment, the reflector 20 is provided between the speakerphone 104 and the microphone element 300, whereby the loud sound from the speakerphone 104 has its sound pressure. Since there is no feedback to the microphone element 300 while maintaining the level, howling is prevented from occurring and extension of reverberation time is suppressed.

Further, due to the difference between the delay circuit 504 provided in the signal processing unit 50 and the spatial path, the sound pickup signal output from the microphone element 300 is given a time delay capable of giving the listener a hearth effect. This allows
The sound image localization is maintained at the position of the speaker S, and in a place where the listener is present, the direction in which the speaker S is present and the direction in which the voice (loud sound) of the speaker S arrives are not different, and the listener is , As if the speaker S were speaking loudly. In addition, the signal processing unit 5
Since the echo canceller 520 is provided at 0, the loud sound from the speakerphone 104 is transmitted to the microphone element 30.
Even if the feedback is returned to 0 to some extent, the feedback can be removed from the sound pickup signal.

<Second Embodiment> In the first embodiment described above, the loudspeaker 1 has a microphone and a speaker integrated with each other. In this embodiment, an indoor loudspeaker system in which a microphone and a speaker are separated will be described.

FIG. 7 is a top view showing the configuration of the indoor loudspeaker system according to the second embodiment of the present invention, and FIG. 8 is a side view showing the configuration of the indoor loudspeaker system. As shown in FIGS. 7 and 8, the indoor loudspeaker system includes a speaker device 10a, a microphone 30, and a signal processing unit 50.

The speaker device 10a is arranged at each of the four corners of the room space. FIG. 9 is a schematic diagram showing the configuration of the speaker device 10a. As shown in the figure, inside the speaker device 10a, there is provided a line sound source speakerphone 104a in which sound sources 1040 such as a small-diameter cone type speakerphone are arranged in series. In addition, the speaker device 10
a is a stand 1 extending coaxially with the longitudinal axis of the sound source 1040
08a, the stand 108a is a sound source 1
The speaker device 10a is supported so that the column direction of 040 is the vertical direction.

In this configuration, the speaker device 10a
Forms a service zone S as shown in FIG.
Specifically, the speaker device 10a emits sound in the horizontal direction, and the sound pressure level of the loud sound in the upper and lower spaces of the speaker device 10a is sufficiently smaller than the sound pressure level of the loud sound in the service zone S. It is supposed to be. That is, as shown in FIG. 10, the service zone S is approximately the same length as the vertical length T of the line source speakerphone 104a in the vertical plane, and is substantially omnidirectional in the horizontal plane. , Or bidirectional. Therefore, when the speaker device 10a is arranged at the corner of the room, the radiation angle θ in the horizontal plane of the service zone S is about 90 degrees. It is desirable that the speaker device 10a be provided at a height such that the service zone S is formed at the height of the listener's ears.

As shown in FIG. 8, the microphone 3
0 is provided with a microphone element 300a having a unidirectional sound collecting characteristic. The microphone 30 is suspended from the ceiling of the room space. Where the microphone 3
The microphone element 300a of 0 has a directivity downward in the vertical direction and is arranged at a height such that the microphone element 300a does not enter the service zone S formed by each speaker device 10a. The signal processing unit 50 is the same as that described in the first embodiment, and performs various signal processing on the sound pickup signal output from the microphone element 300a and outputs the signal to the line sound source speakerphone 104a.

In the indoor loudspeaker system having this structure, the sound produced by the speaker S is collected by the microphone element 300a suspended from the ceiling. The microphone element 300 a generates a sound pickup signal corresponding to the picked up sound and outputs the sound pickup signal to the signal processing unit 50. An echo canceller 520 included in the signal processing unit 50 removes an acoustic echo component from the collected sound signal, and then a delay circuit 504 adds a time delay capable of giving a hearth effect to a listener. Then, the sound pickup signal to which the time delay has been added is subjected to gain adjustment in the frequency domain by the equalizer 506 and then amplified by the power amplifier 508, and the line sound source speakerphone 1 of each speaker device 10a.
It is output to 04a. As a result, each speaker device 10
A loud sound is emitted in the service zone S of a.

As described above, the microphone element 300
a is installed outside the service zone S formed by each speaker device 10a, and the microphone element 300a
Howling is prevented because the sound pressure level of the loud sound at the installation location of is reduced. Further, the delay circuit 504 provided in the signal processing unit 50 adds a time delay that can give the listener a hearth effect, to the sound pickup signal output from the microphone element 300a. As a result, the sound image localization is maintained at the position of the speaker S. Further, since the echo canceller 520 is provided in the signal processing unit 50, even if the loud sound from the line source speakerphone 104a is returned to the microphone element 300a to some extent, the returned sound can be removed from the sound pickup signal. .

As described above, according to the second embodiment, howling is prevented and the sound image localization can be maintained at the position of the speaker S. Further, the speaker device 10a
Since the microphones 30 and the microphones 30 can be individually arranged, the speaker device 10a and the speaker device 10a are provided so that the listener can easily hear the voice of the speaker S depending on the shape of the room space, the arrangement of the listeners (speakers), and the like. The microphone 30 can be arranged in the room space.

<Modifications of Each Embodiment> The above-described embodiments are merely examples and show one aspect of the present invention, and can be arbitrarily changed within the scope of the present invention.
Therefore, various modifications will be described below.

<Modification 1> In the above-described first embodiment, the loudspeaker 1 is arranged on a table such as a round table, and the utterance sound of the speaker S is guided by the reflector 20 and the table and the microphone 3 is used.
Although 0 has been reached, the first embodiment may be modified as shown in FIG. 11 in order to use the invention in a room space without a desk. That is, the plate 70 may be provided below the reflection plate 20, and the first embodiment may be modified so that the plate 70 is supported by the stand 80.

<Modification 2> In the above-described first embodiment, the microphone 30 is provided at the bottom of the parabolic reflector 20 and the speaker 10 is provided at the center of the top of the reflector 20. However, the sound collection space area of the microphone 30 and the sound emission space area of the speaker unit 10 are arranged in the reflection plate 2.
The microphone 30 and the speaker unit 10 may be provided so as to be separated by 0. For example, the microphone 30 may be provided at the center of the upper surface of the reflector 20, and the speaker unit 10 may be provided at the bottom of the lower surface of the reflector 20.

FIG. 12 is a sectional view showing the structure of a loudspeaker according to this modification. As shown in the figure, the microphone 30 includes a microphone element 300, and the microphone element 300 is attached and fixed to the reflection plate 20 by legs 304. Also, the microphone element 300
A signal processing unit 50 is provided below the.
Microphone element 300, signal processing unit 50, and leg 3
04 is covered with a dome-shaped microphone cover 302,
Protected. On the other hand, the speaker unit 10 has a line source speakerphone 104a for emitting a loud sound in the horizontal direction of the drawing.
Is provided, and an arrow A in FIG.
A loud sound is emitted in the direction indicated by.

In this structure, the sound collection space area of the microphone 30 is formed above the reflection plate 20, while the sound emission space area of the speaker unit 10 is formed below the reflection plate 20. Therefore, the loud sound from the speaker unit 10 is prevented from returning to the microphone 30. This prevents the howling from being uttered.

<Modification 3> In the above-described second embodiment, the microphone 30 is provided on the ceiling. However, if the microphone element 300a of the microphone 30 is installed outside the service zone S of the speaker device 10a, the microphone 30 can be installed at any location in the room space. (1) For example, as shown in FIGS. 13 and 14, the second embodiment may be modified so that the microphone 30 is located above the speaker device 10a. Specifically, a bar member 31 extending in the vertical direction is provided above the speaker device 10a.
0 is provided, and the microphone 30 is provided at the upper end of the rod member 310. A microphone element (not shown) included in the microphone 30 has unidirectionality, and the microphone element is provided inside the microphone 30 so that the directional direction thereof is diagonally downward. In this configuration, as indicated by arrow A in FIG.
Since the loud sound from the speaker device 10a is emitted in the horizontal direction, the loud sound is prevented from returning to the microphone 30.

(2) Further, as shown in FIGS. 15 and 16, the speaker device 10b is arranged on the ceiling of the room space,
The second embodiment may be modified so that the microphone 30b is arranged at each of the four corners of the room space. More specifically, each microphone 30b includes a constant directivity microphone element, and picks up a sound (indicated by an arrow B in FIGS. 15 and 16) traveling in parallel with the floor. On the other hand, the speaker device 10b is provided with a unidirectional speakerphone, and is installed on the ceiling in a posture in which the direction of the speakerphone is vertically downward. In this configuration, the loud sound from the speaker device 10b is emitted from the ceiling toward the floor (indicated by the arrow A in FIG. 16), and the loud sound does not return to the microphone 30b.

(3) Further, as shown in FIG. 17, the second embodiment may be modified so that the speaker device 10a is arranged on the table. In this configuration, since the loud sound is emitted from the speaker device 10a in the horizontal direction, the loud sound is prevented from returning to the microphone 30b. As shown in FIG. 18, the speaker device 10a is placed on a table, and the microphone 30b is attached and fixed to the upper end of the speaker device 10a via a rod member 310 for keeping a distance from the upper end. Of course, it is okay.

<Modification 4> In the above-described second embodiment, the microphone element 300a of the microphone 30 is installed outside the service zone S of the speaker device 10a. Therefore, in this modification, the microphone element 300a is
Was installed in the service zone S of the speaker device 10a. FIG. 19 is a side view showing the configuration of the indoor loudspeaker system according to this modification. As shown in the figure, a parabolic reflector 20 is placed on the table, and
A microphone 30 is provided on the bottom of the lower surface of the reflection plate 20. These reflector 20 and microphone 30
Are the same as those described in the first embodiment.
A speaker device 10a is provided on the ceiling located above the reflection plate 20. The speaker device 10a is
It has a unidirectional speakerphone inside, and the pointing direction is vertically downward.

In this configuration, the microphone 30 is
Speaker S coming from the horizontal direction in the figure (indicated by arrow B in the figure)
Collect the vocalization sound of. On the other hand, the speaker device 10a emits a loud sound in the vertical direction (indicated by an arrow A in the figure). This loud sound is reflected by the reflection plate 20 toward the ceiling, and therefore the microphone 30 provided at the bottom of the reflection plate 20.
In addition, the return of the loud sound is prevented. Note that FIG.
As shown in, a microphone 30 for picking up sound coming from a vertically downward direction is provided on the ceiling, while a horizontal direction (indicated by an arrow A in the figure) is provided on the bottom surface of the lower surface of the reflection plate 20.
A speaker device 10a that emits sound may be provided.

<Modification 5> In the above-described first and second embodiments, the case where the reflection plate 20 has a parabolic shape has been described as an example, but the invention is not limited to this. That is, the shape of the reflection plate 20 may be a concave surface, and may be, for example, a hyperbolic shape or an exponential curve shape.

<Modification 6> In the above-mentioned first and second embodiments, the case where the loudspeaker and the indoor loudspeaker system of the present invention loudly utter a person's uttered sound is exemplified, but the present invention is not limited to this. That is, according to the loudspeaker and the room loudspeaker system of the present invention, the extension of the reverberation time due to the loudness is suppressed, and further, the sound image localization is kept at the sound source of the direct sound. The present invention may be used when amplifying a musical sound such as.

[0047]

As described above, according to the present invention,
(EN) Provided are a loudspeaker and an indoor loudspeaker system capable of preventing deterioration of intelligibility due to howling and echo.

[0048]

[Brief description of drawings]

FIG. 1 is a diagram showing a mode of use of a loudspeaker according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of the loudspeaker.

FIG. 3 is a block diagram showing an electrical configuration of the signal processing unit together with a microphone element and a speakerphone.

FIG. 4 is a diagram showing the relationship between the time when the uttered sound of the speaker S reaches the listener and the sound pressure level of the uttered sound that reaches the listener.

FIG. 5 is a diagram showing an example of the relationship between the time when the loud sound from the speakerphone reaches the listener and the sound pressure level of the loud sound that reaches the listener.

FIG. 6 is a diagram showing a relationship between a delay time τ and a sound effect.

FIG. 7 is a top view showing a configuration of an indoor loudspeaker system according to a second embodiment of the present invention.

FIG. 8 is a side view showing the configuration of the indoor loudspeaker system.

FIG. 9 is a schematic diagram showing a configuration of the speaker device 10a.

FIG. 10 is a conceptual diagram showing a service zone formed by the speaker device 10a.

FIG. 11 is a cross-sectional view showing the configuration of a loudspeaker according to a first modification of the first embodiment.

FIG. 12 is a side view showing the configuration of a loudspeaker according to a second modification of the first embodiment.

FIG. 13 is a top view showing a configuration of an indoor loudspeaker system according to a third modification of the second embodiment.

FIG. 14 is a side view showing the configuration of the indoor loudspeaker system.

FIG. 15 is a top view showing a configuration of an indoor loudspeaker system according to another modification.

FIG. 16 is a side view showing the configuration of the indoor loudspeaker system.

FIG. 17 is a side view showing a configuration of an indoor loudspeaker system according to another modification.

FIG. 18 is a side view showing a configuration of an indoor loudspeaker system according to another modification.

FIG. 19 is a side view showing a configuration of an indoor loudspeaker system according to a fourth modified example of the second embodiment.

FIG. 20 is a side view showing a configuration of an indoor loudspeaker system according to another modification.

FIG. 21 is a diagram showing a configuration of a conventional indoor loudspeaker system.

FIG. 22 is a block diagram showing an electrical configuration of a conventional indoor loudspeaker system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Loudspeaker, 10 ... Speaker part, 10a, 10b ... Speaker device, 20 ... Reflector, 30 ... Microphone, 40
... leg, 50 ... signal processing unit, 104 ... speakerphone, 104a ... line sound source speakerphone, 300, 300a
... microphone element, 504 ... delay circuit, 520 ... echo canceller.

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) H04S 7/00 H04S 7/00 F

Claims (5)

[Claims] 1. A sound collecting unit which is provided in the room space and outputs an electric signal according to the collected sound, and a sound emitting unit which is provided in the room space and emits sound according to the electric signal. A loudspeaker device comprising: a means and a plate material that reflects sound, and is sandwiched between the sound collecting means and the sound emitting means. 2. A signal delay means for giving a time delay to an electric signal output from the sound collecting means within a time range in which no echo is generated and a Haas effect is obtained for a listener. The loudspeaker according to claim 1, wherein: 3. A signal removing unit for removing a signal component corresponding to the sound emitted by the sound emitting unit from the electric signal output from the sound collecting unit. Or the loudspeaker according to 2. 4. A sound collecting means provided in a room space for outputting an electric signal according to a collected sound, and a hearth effect for a listener within a time range in which no echo occurs. A signal delay means for applying a time delay to the electric signal and outputting the electric signal, and a means for emitting a sound according to the electric signal output from the signal delay means, wherein the sound collecting means is provided in the sound emission service zone. An indoor loudspeaker system comprising: a sound emitting unit provided in the room space so as not to be included. 5. The signal removing means for removing a signal component corresponding to a sound emitted by the sound emitting means from an electric signal output from the sound collecting means. Indoor loudspeaker system.