JP7275947B2 - Sound pickup device and in-vehicle karaoke device - Google Patents

Description

The present disclosure relates to a sound collecting device and an in-vehicle karaoke device.

2. Description of the Related Art Various techniques have been proposed for supporting conversations between a plurality of passengers in a vehicle or for enjoying karaoke in the vehicle using a microphone unit and a speaker arranged in the vehicle. For example, Patent Document 1 discloses an in-vehicle conversation system having a super-directional microphone unit that collects the voice of a passenger in a vehicle, and a speaker that outputs the amplified voice picked up by the super-directive microphone unit. The invention of In the in-vehicle conversation system disclosed in Patent Document 1, the speaker is installed outside the sound pickup range of the super-directional microphone unit from the viewpoint of suppressing howling.

Utility Model Registration No. 31900554

However, since the in-vehicle conversation system disclosed in Patent Document 1 uses a super-directional microphone unit, there is a problem that both the voice of the driver and the voice of the passenger in the front passenger seat cannot be picked up at the same time.

It is conceivable to use a bidirectional microphone unit to simultaneously pick up both the voice of the driver and the voice of the passenger in the front passenger seat. Since the bidirectional microphone unit has low sensitivity in the low frequency range, the output signal of the bidirectional microphone unit is sometimes subjected to signal processing for electrically amplifying the volume of the low frequency range. However, if the sound volume of the bass range is electrically amplified, the self-noise is also amplified at the same ratio, resulting in a decrease in the S/N ratio.

The present disclosure has been made in view of such circumstances, and aims to provide a technique for improving the sensitivity of a sound pickup device having bidirectionality in the bass range without lowering the S/N ratio. be one of

One aspect of a sound collecting device according to the present disclosure has bidirectionality along a first axis, with a first point and a second point spaced apart by a first distance on the first axis. and a bi-directivity along a second axis that substantially overlaps with the first axis, the second axis having a distance greater than the first distance a second microphone unit for picking up sounds arriving at a third point and a fourth point spaced apart by a second short interval; and a first output signal output from the first microphone unit a synthesizing unit that synthesizes the second output signal output from the second microphone unit and outputs the synthesized signal.

Further, one aspect of the in-vehicle karaoke device according to the present disclosure includes: a first speaker arranged in a compartment of a vehicle; a second speaker facing the first speaker; the sound collecting device arranged in the vehicle compartment so that the direction from one of the speakers to the other intersects the first axis and the second axis, and a sound signal representing accompaniment sound of karaoke and a signal processing unit that adds output signals of the sound collecting device and outputs the result to the first speaker and the second speaker.

Further, one aspect of the in-vehicle karaoke device according to the present disclosure includes a first speaker arranged in a compartment of a vehicle, a second speaker facing the first speaker, the first speaker and the second speaker. said sound collecting device arranged so that at least one of said first axis and said second axis substantially overlaps with said direction at the midpoint of the direction from one of said speakers to the other; and karaoke accompaniment sound and a signal processing unit that synthesizes a sound signal representing and an output signal of the sound collecting device and outputs the result to the first speaker and the second speaker.

It is a figure which shows the structural example of 1 A of vehicle-mounted karaoke apparatuses containing 10 A of sound collection apparatuses which concern on 1st Embodiment. FIG. 3 is a diagram showing an arrangement example of a sound collecting device 10A, a speaker 20-1, and a speaker 20-2 in a cabin CR of a vehicle C in which the in-vehicle karaoke device 1A is installed. 2 is a plan view of the sound pickup device 10A viewed from the z-axis direction; FIG. It is a cross-sectional view along the XX' line of the sound pickup device 10A. It is the side view which looked at 10 A of sound collection apparatuses from the X' direction. FIG. 11 is a diagram for explaining a simulation of directivity characteristics of the microphone unit 110A; FIG. 4 is a diagram showing directivity characteristics of a microphone unit 110A-1 included in the sound pickup device 10A; FIG. 4 is a diagram showing directivity characteristics of a microphone unit 110A-2 included in the sound pickup device 10A; 4 is a diagram showing an example of frequency characteristics of each of a microphone unit 110A-1 and a microphone unit 110A-2 included in the sound pickup device 10A; FIG. FIG. 3 is a diagram showing an example of frequency characteristics of a first output signal S1 output from a microphone unit 110A-1, a low-pass filter 122-1, and an output signal S1' of the low-pass filter 122-1; FIG. 4 is a diagram showing an example of frequency characteristics of a second output signal S2 output from a microphone unit 110A-2, a low-pass filter 122-2, and an output signal S2' of the low-pass filter 122-2; FIG. 4 is a diagram showing an example of frequency characteristics of an output signal S1′, an output signal S2′, and an output signal SS of a synthesizing section 120A; It is a figure which shows the structural example of the vehicle-mounted karaoke apparatus 1B containing the sound-collection apparatus 10B which concerns on 2nd Embodiment. 2 is a plan view of the sound pickup device 10B; FIG. It is a sectional view along the XX' line of sound collection device 10B. It is the side view which looked at the sound collection device 10B from the X' direction. It is a figure which shows the structural example of 1 C of vehicle-mounted karaoke apparatuses containing 10 C of sound collection apparatuses which concern on 3rd Embodiment. 2 is a plan view of the sound pickup device 10C; FIG. It is a cross-sectional view along the XX' line of the sound pickup device 10C. FIG. 10 is a diagram showing an example of arrangement of a sound collecting device 10A, a speaker 20-1, and a speaker 20-2 in modification (1); It is a figure for demonstrating the vehicle-mounted karaoke apparatus of a modification (2). It is a figure for demonstrating the vehicle-mounted karaoke apparatus of a modification (2). FIG. 11 is a diagram showing a configuration example of a sound collecting device 10D of Modified Example (3); 2 is a plan view of the sound pickup device 10D; FIG. It is a sectional view along the XX' line of sound collection device 10D.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each part in the drawings are appropriately different from the actual ones. Moreover, the embodiments described below are preferred specific examples of the present disclosure. Therefore, various technically preferable limitations are applied to the present embodiment. However, the scope of the present disclosure is not limited to these forms unless there is a description to the effect that the present disclosure is particularly limited in the following description.

<1. First Embodiment>
FIG. 1 is a diagram showing a configuration example of an in-vehicle karaoke device 1A including a sound pickup device 10A according to the first embodiment of the present disclosure. As shown in FIG. 1, the in-vehicle karaoke device 1A includes speakers 20-1 and 20-2, and a signal processing section 30 in addition to the sound pickup device 10A. In the in-vehicle karaoke apparatus 1A shown in FIG. 1, the sound pickup device 10A has bidirectionality. The sound collection device 10A collects the singing voice of the driver and the singing voice of the passenger in the front passenger seat. The sound collection device 10A provides the signal processing section 30 with an output signal SS representing the sound waveform of the collected sound. The signal processing unit 30 is supplied with an accompaniment sound signal representing the waveform of the karaoke accompaniment sound from a sound source (not shown). The signal processing unit 30 is, for example, a DSP (Digital Signal Processor). The signal processing unit 30 adds the accompaniment sound signal to the output signal SS of the sound collecting device 10A, distributes the addition result to the speaker 20-1 and the speaker 20-2, and outputs the result.

FIG. 2 is a plan view of a vehicle C equipped with an in-vehicle karaoke device 1A. Four seats 51 to 54 arranged in a rectangular shape, a ceiling 6, a front right door 71, a front left door 72, a rear right door 73, and a rear left door 74 are arranged in the compartment CR of the vehicle C. be done. If the vehicle C is a product for Japan, the seat 51 is the driver's seat and the seat 52 is the passenger's seat. However, if the vehicle C is a product for the US or Europe, the seat 51 is the front passenger's seat and the seat 52 is the driver's seat. In the following description, it is assumed that vehicle C is a product for Japan. Seat 53 is the rear right seat and seat 54 is the rear left seat. Each of the seats 51-54 is made of cloth or leather. The seats 51-54 face in a common direction.

Although detailed illustration is omitted in FIG. 2, each of the sound collecting device 10A, the speaker 20-1 and the speaker 20-2 is connected to the signal processing section 30 via a signal line such as an audio cable. Although illustration of the signal processing unit 30 is also omitted in FIG. 2, the signal processing unit 30 is arranged in the console on the driver's seat side of the vehicle C.

The speaker 20-1 is an example of a first speaker arranged in the passenger compartment CR of the vehicle C, and the speaker 20-2 is an example of a second speaker facing the first speaker. Specifically, each of speaker 20-1 and speaker 20-2 is a so-called door speaker. The speaker 20 - 1 is arranged on the front light door 71 with its sound emitting surface facing the seat 51 . The speaker 20 - 2 is arranged on the front left door 72 with its sound emitting surface facing the seat 52 .

The sound collecting device 10A is provided at a position where the distance from the speaker 20-1 and the distance from the speaker 20-2 are substantially the same. Note that the distance from the speaker 20-1 and the distance from the speaker 20-2 are substantially equal when the sound pickup device 10A is provided at the midpoint of the line connecting the speaker 20-1 and the speaker 20-2. In addition, it means that the sound pickup device 10A is provided in the vicinity of the midpoint within a technical error range. Specific installation locations of the sound collection device 10A include a vehicle dashboard, a sun visor, the rear surface of the rearview mirror, the ceiling 6, and the like.

The sound collecting device 10A is arranged in a posture in which the directivity axis of the sound collecting device 10A is substantially orthogonal to the direction in which the speaker 20-2 is viewed from the speaker 20-1 and the vertical direction. Hereinafter, the direction from the speaker 20-1 to the speaker 20-2 in the passenger compartment CR is called the y-axis direction, the vertical direction is called the z-axis direction, and the direction orthogonal to both the y-axis direction and the z-axis direction is called the x-axis direction. . In this embodiment, the directivity axis of the sound pickup device 10A is along the x-axis direction. The fact that the directivity axis of the sound pickup device 10A is substantially orthogonal to the y-axis direction and the z-axis direction means that it is not only strictly orthogonal but also orthogonal within a technical error range. By providing the sound collecting device 10A in the above posture, the speakers 20-1 and 20-2 are positioned in a direction in which the sound collecting device 10A does not have sensitivity, and howling can be avoided. Further, according to the arrangement shown in FIG. 2, it is possible to exclude noises that may come from any direction, such as road noises, coming from directions that do not have sensitivity from the sound pickup targets. Furthermore, according to the arrangement shown in FIG. 2, since the sound source of the singing voice of the driver or the like is positioned in the directional axis direction of the sound collecting device 10A, a sufficient amplification effect can be obtained.

As described above, conventional bidirectional sound pickup devices, such as bidirectional microphone units having only one diaphragm, have the disadvantage of low sensitivity in the low frequency range, and the volume of the low frequency range is electrically controlled. It was necessary to take countermeasures such as lifting it up. On the other hand, the sound pickup device 10A of the present embodiment is configured so as to improve the sensitivity of the bass range, and does not require electrical amplification of the bass range. The sound collection device 10A will be mainly described below.

FIG. 1 shows an example of the electrical configuration of the sound pickup device 10A.
As shown in FIG. 1, the sound collection device 10A has microphone units 110A-1 and 110A-2, and a synthesizing section 120A. Microphone unit 110A-1 is an example of a first microphone unit with bidirectionality along a first axis, and microphone unit 110A-2 is an example of a second microphone with bidirectionality along a second axis. An example of a unit. Hereinafter, when there is no need to distinguish between the microphone units 110A-1 and 110A-2, they are referred to as "microphone unit 110A." The microphone unit 110A includes a bidirectional microphone unit 112 having one diaphragm, and an amplifier 114 that amplifies the output signal of the bidirectional microphone unit 112 and outputs it to the synthesizing section 120A. The synthesizing unit 120A adds the first output signal S1 output from the microphone unit 110A-1 and the second output signal S2 output from the microphone unit 110A-2, and generates an output signal SS that is the addition result. Output to the signal processing unit 30 .

FIG. 3 is a plan view of the sound pickup device 10A viewed from the z direction. The XX′ line in FIG. 3 is along the directional axis of the sound pickup device 10A. FIG. 4 is a diagram showing an example of a cross section of the sound pickup device 10A along a plane along line XX' in FIG. 3, that is, a plane including the directivity axis of the sound pickup device 10A. FIG. 5 is a side view of the sound pickup device 10A viewed from the X' side. 4 and 5, reference numeral 112-1a indicates the diaphragm of the bidirectional microphone unit 112 in the microphone unit 110A-1, and reference numeral 112-2a indicates the diaphragm of the bidirectional microphone unit 112 in the microphone unit 110A-2. point to In FIGS. 3 and 4, the A1A1' line is a line segment along the first axis, and the A2A2' line is a line segment along the second axis. 3 to 5, reference numeral 130 indicates a board on which the synthesizing section 120A is provided, and reference numeral 140A indicates a case housing the microphone units 110A-1 and 110A-2. That is, the sound collecting device 10A in this embodiment has the board 130 and the case 140A in addition to the microphone unit 110A and the synthesizing section 120A.

In the sound pickup device 10A, the microphone unit 110A-1 is provided so that the first axis and the XX' line are parallel within a range including manufacturing technical errors. Similarly, in the sound pickup device 10A, the microphone unit 110A-2 is provided so that the second axis is parallel to the XX' line within the range of errors in manufacturing technology. As shown in FIG. 3, the microphone unit 110A-1 and the microphone unit 110A-2 are provided so that the first axis and the second axis overlap when viewed from the z-axis direction. Also, the microphone unit 110A-1 and the microphone unit 110A-2 are provided so that the distance in the z-axis direction between the first axis and the second axis is sufficiently small. The reason why the distance in the z-axis direction between the first axis and the second axis is sufficiently small is that the sound picked up by the microphone unit 110A-1 and the sound picked up by the microphone unit 110A-2 are different. This is because the sound pressure difference and the phase difference are sufficiently small so that the sound picked up by the microphone unit 110A-1 and the sound picked up by the microphone unit 110A-2 can be regarded as the same. That is, the first axis and the second axis substantially overlap. Substantially overlapping includes not only the case where the first axis and the second axis completely overlap but also the case where the first axis and the second axis are apart. However, even when the first axis and the second axis are separated, the sound picked up by the microphone unit 110A-1 and the sound picked up by the microphone unit 110A-2 are substantially different. will be the same as

As shown in FIGS. 3 to 5, the case 140A includes a first member 142, which is a tubular member whose longitudinal direction is the XX′ line direction, and a second tubular member, which is also a tubular member whose longitudinal direction is the XX′ line direction. It is formed by connecting two members 144 and . As shown in FIGS. 3 and 4, the longitudinal length of the second member 144 is shorter than the longitudinal length of the first member 142 . As shown in FIG. 3, the length of the first member 142 in the longitudinal direction is D1, and the length of the second member 144 in the same direction is D2 (D2<D1). In this embodiment, D1 is 50 mm and D2 is 20 mm. As shown in FIG. 4, openings 152-1 and 152-2 are provided at both ends of the first member 142 in the x-axis direction, and openings 152-1 and 152-2 are provided at both ends of the second member 144 in the x-axis direction. 3 and opening 152-4 are provided. Hereinafter, a position equidistant in the x-axis direction from both ends of the first member 142 in the x-axis direction will be referred to as the “center of the first member 142”, The distance position is called "the center of the second member 144".

As shown in FIGS. 3 and 4, the case 140A attaches the second member 144 to the first member 142 so that the center of the first member 142 and the center of the second member 144 are aligned on a straight line along the z-axis. Formed by connecting. The diaphragm 112-1a of the microphone unit 110A-1 is provided at the center of the first member 142 or near the center within a technical margin of error. Diaphragm 112-1a is provided in the internal space of first member 142 with one surface facing opening 152-1 and the other surface facing opening 152-2. The diaphragm 112-2a of the microphone unit 110A-2 is provided at the center of the second member 144 or near the center within a technical error range. The diaphragm 112-2a is provided in the internal space of the second member 144 with one surface facing the opening 152-3 and the other surface facing the opening 152-4. Since the second member 144 is connected to the first member 142 as described above, the microphone unit 110A-2 is connected to the microphone unit 110A-1 in the sound pickup device 10A.

Sound emitted from a sound source and arriving at opening 152-1 passes through the inner space of first member 142 and is guided to one surface of diaphragm 112-1a. Similarly, the sound emitted from the sound source and arriving at the opening 152-2 is guided to the other surface of the diaphragm 112-1a via the inner space of the first member 142. FIG. That is, as shown in FIG. 4, the first member 142 guides the sound arriving at the first point P1 above the opening 152-1 and on the first axis to one surface of the diaphragm 112-1a. 1 tube 162 . Also, as shown in FIG. 4, the first member 142 guides sound arriving at a second point P2 on the second axis above the opening 152-2 to the other surface of the diaphragm 112-1a. 2 tubes 164 . Since the length of the first member 142 in the x-axis direction is D1, the first point P1 and the second point P2, which are the sound pickup positions of the microphone unit 110A-1, are spaced apart on the first axis. Line up across D1.

Since the diaphragm 112-1a in the microphone unit 110A-1 is provided at or near the center of the first member 142, the tube length of the first tube 162 and the tube length of the second tube 164 are substantially equal. Since the tube length of the first tube 162 and the tube length of the second tube 164 are substantially equal, the difference between the sound guided to one side of the diaphragm 112-1a and the sound guided to the other side of the diaphragm 112-1a is The phase difference is substantially equal to the phase difference between the sound arriving at the first point P1 and the sound arriving at the second point P2. In the microphone unit 110A-1, the diaphragm 112 is arranged according to the sound pressure difference of the sound arriving at each of the first point P1 and the second point P2 which are arranged on the first axis, which is the directional axis, with the interval D1 therebetween. -1a vibrates, and this vibration is converted into an electrical signal and output. Similarly, in the microphone unit 110A-2, a third point P3 (see FIG. 4) on the second axis and on the opening 152-3 and a fourth point P4 on the second axis and on the opening 152-4 (see FIG. 4), the diaphragm 112-2a vibrates according to the sound pressure difference of the sound arriving at each of them, and this vibration is converted into an electric signal and output. Since the length of the second member 144 in the x-axis direction is D2, the third point P3 and the fourth point P4, which are the sound pickup positions of the microphone unit 110A-2, are spaced apart on the second axis. Line up across D2.

なお、数１及び数２において、ｊは虚数単位であり、πは円周率であり、ｅは自然対数の底である。また、数１におけるｔ_１はＬ_１／ｃ（ｃは音速）であり、数２におけるｔ_２はＬ_２／ｃである。また、数１におけるＬ_１は以下の数３にしたがって算出され、数２におけるＬ_２は以下の数４にしたがって算出される。

FIG. 6 is a diagram for explaining a simulation for verifying the directional characteristics of the microphone unit 110A. In this simulation, as shown in FIG. 6, a distance L (in this embodiment, , L=500 mm). A sound wave radiated from the sound source SP spreads in a spherical shape. Therefore, when the frequency of the sound radiated from the sound source SP is f, and the amplitude of the sound pressure at the position separated by the distance L from the sound source SP is 1, then at the first point P1 (the third point P3) The sound pressure PA and the sound pressure PB at the second point P2 (fourth point P4) are calculated by Equations 1 and 2 below.

In Equations 1 and 2, j is the unit of imaginary number, π is the constant of pi, and e is the base of natural logarithms. Also, t ₁ in Equation 1 is L ₁ /c (c is the speed of sound), and t ₂ in Equation 2 is L ₂ /c. Also, _L1 in Equation 1 is calculated according to Equation 3 below, and _L2 in Equation 2 is calculated according to Equation 4 below.

For each frequency of f=10 Hz, 100 Hz, and 1000 Hz, while changing the angle θ in the range of 0≦θ<360°, calculating the absolute value of the differential pressure between the sound pressure PA and the sound pressure PB yields the following for the microphone unit 110A-1: , the directivity characteristic shown in FIG. 7 is obtained, and the directivity characteristic shown in FIG. 8 is obtained for the microphone unit 110A-2. As is clear from FIGS. 7 and 8, the microphone unit 110A provides bi-directivity for each frequency of 10 Hz, 100 Hz, and 1000 Hz.

FIG. 9 is a diagram showing an example of the differential pressure frequency characteristic FT1 represented by the first output signal S1 and the differential pressure frequency characteristic FT2 represented by the second output signal S2. As is clear from FIG. 9, the sensitivity of the microphone unit 110A-1 is improved in the bass range to around 5000 Hz compared to the microphone unit 110A-2. The reason for this is as follows. In this sound range, the difference between the phase of the sound arriving at the first point P1 and the phase of the sound arriving at the second point P2 is the phase difference between the phase of the sound arriving at the third point P3 and the phase of the sound arriving at the fourth point P4. is larger than the phase difference of the sound arriving at Therefore, the microphone unit 110A-1 has higher sensitivity in the bass range than the microphone unit 110A-2. In the microphone unit 110A-1, the first point Since the phase of the sound arriving at P1 matches the phase of the sound arriving at the second point P2, the sensitivity becomes extremely small, and as shown in the frequency characteristic FT1 in FIG. produces a dip. Also, at the frequency where the distance D1 is half the wavelength, that is, fD1P=2c/D1 and odd multiples of fD1P=2c/D1, the phase of the sound arriving at the first point P1 and the phase of the sound arriving at the second point P2 are Since the difference is 180°, the sensitivity becomes maximum, and peaks occur at frequencies of 3500 Hz and odd multiples thereof as shown in the frequency characteristic FT1 of FIG. Similarly, dips and peaks occur for the microphone unit 110A-2.

In the sound collection device 10A of the present embodiment, by synthesizing the first output signal S1 output from the microphone unit 110A-1 and the second output signal S2 output from the microphone unit 110A-2, Improved sensitivity is achieved. In the microphone unit 110A-1, tube resonance may occur for sounds whose wavelength/4 is an odd multiple of the tube length (D1/2) of the first tube 162 and the second tube 164. FIG. The fundamental mode frequency of this tube resonance is fDT=c/(2×D1), which matches the frequency fD1P at which the microphone unit 110A-1 has the maximum sensitivity. The influence of this pipe resonance can be avoided by a low-pass filter 122-1, which will be described later. In order to more reliably avoid the influence of pipe resonance, a sound absorbing material may be installed inside each of the first pipe 162 and the second pipe 164 or in the openings 152-1 and 152-2.

Synthesis section 120A has low-pass filters 122-1 and 122-2, and adder 124, as shown in FIG. Note that "low-pass filter" is abbreviated as "LPF" in FIG. The low-pass filter 122-1 outputs, among the frequency components contained in the first output signal S1, signal components having frequencies lower than the cutoff frequency F1 to the adder 124 as the output signal S1'. The low-pass filter 122-2 outputs signal components of frequencies lower than the cutoff frequency F2 among the signal components contained in the second output signal S2 to the adder 124 as the output signal S2'. The adder 124 outputs to the signal processing section 30 an output signal SS obtained by adding the output signal S1' of the low-pass filter 122-1 and the output signal S2' of the low-pass filter 122-2. If analog signal processing is used as the signal processing in the synthesizing section 120A, no delay occurs unlike digital signal processing.

FIG. 10 shows an example of the frequency characteristic FT1, the frequency characteristic FL1 of the low-pass filter 122-1, and the frequency characteristic FT1' of the output signal S1'. FIG. 11 is a diagram showing an example of the frequency characteristic FT2, the frequency characteristic FL2 of the low-pass filter 122-2, and the frequency characteristic FT2' of the output signal S2'. The reason why the output signal S1' is generated from the first output signal S1 using the low-pass filter 122-1 is to reduce the dip that appears in the frequency band of 7000 Hz or higher in the first output signal S1. Similarly, the reason why the low-pass filter 122-2 is used to generate the output signal S2' from the second output signal S2 is to reduce the dip that appears in the frequency band of 11000 Hz or higher in the second output signal S2. Thus, the first output signal S1 has a dip in a lower frequency band than the second output signal S2, so the cutoff frequency F1 is set lower than the cutoff frequency F2. For example, cutoff frequency F1 is 795 Hz and cutoff frequency F2 is 4547 Hz.

FIG. 12 is a diagram showing an example of the frequency characteristic FT1', the frequency characteristic FT2', and the frequency characteristic FTS of the differential pressure represented by the output signal SS. Referring to FIG. 12, the output signal SS has a larger differential pressure at almost all frequencies from 10 Hz to 100000 Hz than the output signal S1', and it can be seen that the dip near 7000 Hz has been eliminated in particular. . Further, referring to FIG. 12, the differential pressure of the output signal SS is about 11 db larger in the vicinity of 100 Hz than in the output signal S2', the differential pressure is larger by about 8 db in the vicinity of 1000 Hz, and the differential pressure is larger by about 8 db in the vicinity of 1000 Hz. It can be seen that the differential pressures of the two are substantially equal at the frequency. As described above, according to the sound collection device 10A of the present embodiment, the sensitivity in the low range is improved compared to the case where the microphone unit 110A-1 or the microphone unit 110A-2 is used alone, so that the signal in the low range There is no need to electrically amplify the components.

As described above, the sound collecting device 10A of this embodiment has the microphone unit 110A-1, the microphone unit 110A-2, and the synthesizing section 120A. The microphone unit 110A-1 is bi-directional along a first axis and picks up sounds arriving at a first point P1 and a second point P2 spaced apart by a first distance on the first axis. is a first microphone unit that picks up the sound of Microphone unit 110A-2 is coupled to the first microphone unit and has bidirectionality along a second axis parallel to the first axis and less than the first spacing on the second axis. A second microphone unit for picking up sounds arriving at a third point P3 and a fourth point P4 separated by a second distance. The synthesizing section 120A then synthesizes the first output signal output from the first microphone unit and the second output signal output from the second microphone unit, and outputs the synthesized signal. Due to such a configuration, according to the sound pickup device 10A of the present embodiment, it is possible to improve the sensitivity of the bass range without reducing the S/N ratio without the need for electrical amplification of the bass range. Become.

<2. Second Embodiment>
FIG. 13 is a diagram showing a configuration example of an in-vehicle karaoke device 1B including a sound pickup device 10B according to the second embodiment of the present disclosure. In FIG. 13, the same components as in FIG. 1 are given the same reference numerals as in FIG. As is clear from a comparison of FIG. 13 and FIG. 1, the difference between the in-vehicle karaoke apparatus 1B and the in-vehicle karaoke apparatus 1A is that a sound pickup apparatus 10B is provided instead of the sound pickup apparatus 10A. The sound collection device 10B has bidirectionality, like the sound collection device 10A. Although detailed illustration is omitted, the sound collecting device 10B, like the sound collecting device 10A, has a direction in which one of the speaker 20-1 and the speaker 20-2 is viewed from the other, and the directional axis of the sound collecting device 10B. placed in an orthogonal orientation. This is to avoid the occurrence of howling when the sound output from each of the speakers 20-1 and 20-2 is picked up by the sound pickup device 10B.

13 and FIG. 1, the difference between the sound collecting device 10B and the sound collecting device 10A is that the microphone units 110B-1 and 110A-2 are replaced with the microphone units 110B-1 and 110A-2. The point is that the microphone unit 110B-2 is provided. The microphone unit 110B-1 is an example of a first microphone unit having bi-directivity along the first axis like the microphone unit 110A-1 in the first embodiment, and the microphone unit 110B-2 is the first microphone unit in the first embodiment. It is an example of a second microphone unit having bi-directivity along the second axis similar to microphone unit 110A-2 in form. As shown in FIG. 13, in the sound pickup device 10B, the first output signal S1 is output from the microphone unit 110B-1, and the second output signal S2 is output from the microphone unit 110B-2. Hereinafter, when there is no need to distinguish between the microphone units 110B-1 and 110B-2, they are referred to as "microphone unit 110B." The difference between the microphone unit 110B and the microphone unit 110A is that instead of the bidirectional microphone unit 112 and the amplifier 114, the omnidirectional microphone unit 113-1 and the omnidirectional microphone unit 113-2, the amplifier 114-1 and the The difference is that an amplifier 114-2 and a subtractor 116 are provided.

In microphone unit 110B, the output signal of omnidirectional microphone unit 113-1 is amplified by amplifier 114-1 and input to subtractor . Similarly, the output signal of omnidirectional microphone unit 113-2 is input to subtractor 116 after being amplified by amplifier 114-2. In this embodiment, the gain in the amplifier 114-1 and the gain in the amplifier 114-2 are the same value. Subtractor 116 subtracts the output signal of amplifier 114-2 from the output signal of amplifier 114-1 and outputs the result to synthesizing section 120A. In microphone unit 110B-1, amplifier 114-1, amplifier 114-2 and subtractor 116 output signals from omnidirectional microphone unit 113-1 and omnidirectional microphone unit 113-2 in microphone unit 110B-2. It functions as a first generation unit that generates a signal corresponding to the difference between , as a first output signal S1. Similarly, in microphone unit 110B-2, amplifier 114-1, amplifier 114-2, and subtractor 116 are used for omnidirectional microphone unit 113-1 and omnidirectional microphone unit 113-2 in microphone unit 110B-2, respectively. It serves as a second generation unit that generates a signal corresponding to the difference between the output signals of S2 as the second output signal S2. As a result, the microphone unit 110B achieves bidirectionality having a directional axis in the direction in which the omnidirectional microphone unit 113-1 and the omnidirectional microphone unit 113-2 are arranged.

14 is a plan view of the sound pickup device 10B, FIG. 15 is a cross-sectional view along line XX′ along the directional axis of the sound pickup device 10B, and FIG. 16 is a view of the sound pickup device 10B from the X′ direction. Fig. 2 is a viewed side view; In FIGS. 14 to 16, reference numeral 130 indicates a board on which the synthesizing section 120A is provided, and reference numeral 140B indicates a case that accommodates the microphone units 110B-1 and 110B-2. In addition, the A1A1' line in FIGS. 14 and 15 is a line segment along the first axis, and the A2A2' line is a line segment along the second axis. As shown in FIGS. 14 and 15, in this embodiment, the A1A1' line and the A2A2' line coincide with the XX' line.

As shown in FIGS. 14 to 16, case 140B is formed in a flat and substantially rectangular parallelepiped shape. On the plane of the case 140B, sound collection positions of a first point P1, a second point P2, a third point P3, and a fourth point P4 are arranged on the XX' line along the directional axis of the sound collection device 10B. Corresponding openings 152-1, 152-2, 152-3 and 152-4 are provided. As shown in FIG. 14, the distance between the first point P1 and the second point P2 along the first axis is D1, and the first point P1 and the second point P2 are located at the center of the case 140B. are arranged symmetrically. Also, the distance between the third point P3 and the fourth point P4 along the second axis is D2, and the third point P3 and the fourth point P4 are arranged symmetrically when viewed from the center of the case 140B. be. As shown in FIG. 14, D2<D1 also in this embodiment.

As shown in FIGS. 14 and 15, the opening 152-1 is provided with the omnidirectional microphone unit 113-1 of the microphone unit 110B-1, and the opening 152-2 is provided with the omnidirectional microphone unit 110B-1 of the microphone unit 110B-1. A microphone unit 113-2 is provided. That is, the microphone unit 110B-1 picks up the sound arriving at the first point P1 and the sound arriving at the second point P2 provided on the first axis, which is the directional axis, and detects the difference between the two. to output a first output signal S1 corresponding to . As a result, frequency characteristics similar to those of the microphone unit 110A-1 can be obtained.

Further, as shown in FIGS. 14 and 15, the opening 152-3 is provided with the omnidirectional microphone unit 113-1 of the microphone unit 110B-2, and the opening 152-4 is provided with the microphone unit 110B-2. An omnidirectional microphone unit 113-2 is provided. That is, the microphone unit 110B-2 picks up the sound arriving at the third point P3 and the sound arriving at the fourth point P4 provided on the second axis, which is the directional axis, and detects the difference between the two. to output a second output signal S2 corresponding to . As a result, frequency characteristics similar to those of the microphone unit 110A-2 can be obtained.

In the sound collecting device 10B, the first output signal S1 output from the microphone unit 110B-1 and the second output signal S2 output from the microphone unit 110B-2 are synthesized by the synthesizing section 120A, and the synthesizing result is It is output to the signal processing section 30 as an output signal SS. Therefore, even with the sound collecting device 10B of the present embodiment, it is not necessary to electrically amplify the bass range, and it is possible to improve the sensitivity of the bass range without lowering the S/N ratio.

<3. Third Embodiment>
FIG. 17 is a diagram showing a configuration example of an in-vehicle karaoke device 1C including a sound pickup device 10C according to the third embodiment of the present disclosure. In FIG. 17, the same components as in FIG. 13 are labeled with the same reference numerals as in FIG. 17 and 13, the difference between the in-vehicle karaoke device 1C and the in-vehicle karaoke device 1B is that a sound pickup device 10C is provided instead of the sound pickup device 10B. The sound collection device 10C has bidirectionality, like the sound collection device 10B. Similar to the sound pickup device 10B, the sound pickup device 10C is arranged in a posture in which the direction of the speaker 20-1 and the speaker 20-2 viewed from the other is orthogonal to the directivity axis of the sound pickup device 10C. This is to avoid the occurrence of howling when the sound output from each of the speakers 20-1 and 20-2 is picked up by the sound pickup device 10C.

17 and 13, the difference between the sound pickup device 10C and the sound pickup device 10B is that the microphone unit 110B-3 is added in addition to the microphone units 110B-1 and 110B-2. and that the synthesizing unit 120B is provided instead of the synthesizing unit 120A. Microphone unit 110B-3 is an example of a third microphone unit having bi-directionality along the third axis. As is clear from FIG. 17, the configuration of the microphone unit 110B-3 is the same as the configurations of the microphone units 110B-1 and 110B-2.

FIG. 18 is a plan view of the sound pickup device 10C, and FIG. 19 is a cross-sectional view taken along line XX′ along the directional axis of the sound pickup device 10C. Note that the side view of the sound collecting device 10C viewed from the X' direction is the same as the side view of the sound collecting device 10B (see FIG. 16), so the illustration is omitted. In FIGS. 18 and 19, reference numeral 130 indicates a board on which the synthesizing section 120B is provided, and reference numeral 140C indicates a case that accommodates the microphone units 110B-1, 110B-2, and 110B-3. Line A1A1′ in FIGS. 18 and 19 is a line segment along the first axis, which is the directional axis of microphone unit 110B-1, and line A2A2′ is the second axis, which is the directional axis of microphone unit 110B-2. is a line segment along the axis of . A3A3' line in FIGS. 18 and 19 is a line segment along the third axis, which is the directional axis of the microphone unit 110B-3. As shown in FIGS. 18 and 19, in this embodiment, lines A1A1′, A2A2′ and A3A3′ coincide with line XX′.

As shown in FIGS. 18 and 19, the case 140C is formed in a flat and substantially rectangular parallelepiped shape. On the plane of the case 140C, a first point P1, a second point P2, a third point P3, a fourth point P4, and a fifth point P5 are arranged on the XX' line along the directional axis of the sound pickup device 10C. , and the sixth point P6 are provided with openings 152-1, 152-2, 152-3, 152-4, 152-5, and 152-6 corresponding to the respective sound pickup positions. As shown in FIG. 18, the distance between the first point P1 and the second point P2 along the first axis is D1, and the first point P1 and the second point P2 are located at the center of the case 140C. are arranged symmetrically. Also, the distance between the third point P3 and the fourth point P4 along the second axis is D2, and the third point P3 and the fourth point P4 are arranged symmetrically when viewed from the center of the case 140C. be. The distance between the fifth point P5 and the sixth point P6 along the third axis is D3, and the fifth point P5 and the sixth point P6 are arranged symmetrically when viewed from the center of the case 140C. be. As shown in FIG. 18, D2<D1<D3 in this embodiment.

As shown in FIGS. 18 and 19, the opening 152-1 is provided with the omnidirectional microphone unit 113-1 of the microphone unit 110B-1, and the opening 152-2 is provided with the omnidirectional microphone unit 110B-1 of the microphone unit 110B-1. A microphone unit 113-2 is provided. In other words, the microphone unit 110B-1 of the present embodiment also has bi-directivity like the microphone unit 110B-1 of the second embodiment, and has frequency characteristics similar to those of the microphone unit 110A-1. Further, as shown in FIGS. 18 and 19, the opening 152-3 is provided with the omnidirectional microphone unit 113-1 of the microphone unit 110B-2, and the opening 152-4 is provided with the microphone unit 110B-2. An omnidirectional microphone unit 113-2 is provided. In other words, the microphone unit 110B-2 of the present embodiment also has bi-directivity like the microphone unit 110B-2 of the second embodiment, and has frequency characteristics similar to those of the microphone unit 110A-2.

As shown in FIGS. 18 and 19, the omnidirectional microphone unit 113-1 of the microphone unit 110B-3 is provided in the aperture 152-5, and the omnidirectional microphone unit 110B-3 of the microphone unit 110B-3 is provided in the aperture 152-6. A microphone unit 113-2 is provided. That is, the microphone unit 110B-3 picks up the sound arriving at the fifth point P5 and the sound arriving at the sixth point P6, and outputs a signal corresponding to the difference between the two as the third output signal S3. do. Thereby, bidirectionality of the microphone unit 110B-3 is realized. In addition, since the distance D3 between the fifth point P5 and the sixth point P6, which are the sound pickup positions of the microphone unit 110B-3, is larger than the distance D1, the microphone unit 110B-3 is closer to the microphone unit 110B-1 than the microphone unit 110B-1. The sensitivity in the low frequency range also increases.

As is clear from a comparison between FIG. 17 and FIG. 13, the following two points are the differences between the synthesizing section 120B and the synthesizing section 120A. The first difference is that it has a low-pass filter 122-3 in addition to the low-pass filters 122-1 and 122-2. A third output signal S3 output from the microphone unit 110B-3 is applied to the low-pass filter 122-3. The low-pass filter 122-3 passes, as an output signal S3', signal components of frequencies lower than the cutoff frequency F3 among the signal components contained in the third output signal S3. In this embodiment, the cutoff frequency F3 is a frequency lower than the cutoff frequency F1 of the low-pass filter 122-1. A second difference between the synthesizing section 120B and the synthesizing section 120A is that the adder 124 adds the output signal S1', the output signal S2', and the output signal S3' to generate the output signal SS. In this manner, the synthesizing section 120B differs from the synthesizing section 120A in that the output signal SS is generated by synthesizing the first output signal S1, the second output signal S2, and the third output signal S3.

The sound pickup device 10C of the present embodiment also does not require electrical amplification of the bass range, so it is possible to improve the sensitivity of the bass range without lowering the S/N ratio. In addition, since the microphone unit 110B-3 in the present embodiment has higher sensitivity in the bass range than the microphone unit 110B-1, the sensitivity in the bass range of the sound collecting device 10C is higher than that of the sound collecting device 10B.

<4. Variation>
The above embodiment can be variously modified. Specific modification modes are exemplified below. Two or more aspects arbitrarily selected from the following examples may be combined as appropriate unless contradictory.

<4-1. Modification 1>
As shown in FIG. 20, the vehicle-mounted karaoke apparatus 1A may be constructed by arranging the sound pickup device 10A such that the directivity axis of the sound pickup device 10A is in the y-axis direction. If the sound collecting device 10A is arranged at a position substantially equidistant from each of the speaker 20-1 and the speaker 20-2, and the same-phase sound is output from each of the speaker 20-1 and the speaker 20-2, then the speaker Sounds output from each of 20-1 and speaker 20-2 cancel each other out at the positions of diaphragm 112-1a and diaphragm 112-2a. Therefore, even if the sound pickup device 10A is arranged as shown in FIG. 20, the occurrence of howling can be avoided. The arrangement shown in FIG. 20 is effective when suppressing the volume of singing voice and outputting it from each of speaker 20-1 and speaker 20-2. 20, the sound arriving at the first point P1 (see FIG. 4) and the second point P2 (see FIG. 4) from the singer sitting on the seat 51 (or seat 52) Since the phase difference with the sound is increased, the sensitivity in the low frequency range is further improved as compared with the arrangement mode shown in FIG. Similarly, the sound pickup device 10B may be arranged so that the directional axis is in the y-axis direction to form an in-vehicle karaoke device. may be arranged in a car-mounted karaoke device.

<4-2. Modification 2>
The in-vehicle karaoke apparatus 1A of the first embodiment includes the speaker 20-1 and the speaker 20-2, which are door speakers. However, the in-vehicle karaoke apparatus to which the present disclosure is applied may be an in-vehicle karaoke apparatus including speakers 20-3 and 20-4, which are A-pillar speakers, respectively, as shown in FIG. In FIG. 21, illustration of the signal processing unit 30 connected to the sound collecting device 10A and the speakers 20-1 to 20-4 is omitted. In addition, one sound pickup device 10A was included in the in-vehicle karaoke device 1A of the first embodiment. However, as shown in FIG. 22, the in-vehicle karaoke device to which the present disclosure is applied includes a plurality of sound pickup devices (in the example shown in FIG. -1 and sound pickup device 10A-2). Also in FIG. 22, illustration of the signal processing unit 30 connected to the sound collection devices 10A-1 and 10A-2 and the speakers 20-1 and 20-2 is omitted.

<4-3. Modification 3>
In each of the above-described embodiments, an example of application of the sound pickup devices 10A, 10B, and 10C to an in-vehicle karaoke device has been described, but the sound pickup devices 10A, 10B, and 10C may be applied to an in-vehicle hands-free telephone. In addition, the application target of the sound collection devices 10A, 10B, and 10C is not limited to the in-vehicle device. For example, the sound pickup devices 10A, 10B, and 10C may be applied to karaoke machines and hands-free telephones installed in living rooms of houses.

<4-4. Modification 4>
As shown in FIGS. 23, 24 and 25, the microphone unit 110B-1, the microphone unit 110A-2, and the synthesizing unit 120A may be combined to configure the sound pickup device 10D. 23 is a diagram showing an electrical configuration example of the sound pickup device 10D, FIG. 24 is a plan view of the sound pickup device 10D, and FIG. 25 is a cross-sectional view of the sound pickup device 10D taken along line XX′. The sound pickup device 10D shown in FIGS. 23, 24 and 25 also does not require electrical amplification of the bass range, so it is possible to improve the sensitivity of the bass range without lowering the S/N ratio. .

<5. Aspects Grasp from At Least One of the Embodiments and Modifications>
The following aspects can be grasped from at least one of the above-described embodiment and modifications.
One aspect of the sound collecting device is bidirectional along a first axis, with sound arriving at first and second points spaced apart by a first distance on said first axis. and a second microphone unit that has bi-directivity along a second axis that substantially overlaps with the first axis and that is shorter than the first distance on the second axis a second microphone unit for picking up sounds arriving at a third point and a fourth point spaced apart from each other; a first output signal output from the first microphone unit; It is preferable to have a synthesizing section that synthesizes the second output signal output from the microphone unit and outputs the synthesized signal. According to this aspect, the sensitivity in the bass range is improved while achieving bi-directivity along the first axis and the second axis.

In one aspect of the sound collecting device described above, having bi-directionality along a first axis and arriving at a first point and a second point spaced apart by a first distance on said first axis. a first microphone unit that picks up a sound that emits sound, is coupled to the first microphone unit and has bidirectionality along a second axis parallel to the first axis, and on the second axis a second microphone unit for picking up sounds arriving at a third point and a fourth point separated by a second interval shorter than the first interval, and output from the first microphone unit and a synthesizing unit that synthesizes the first output signal output from the second microphone unit and the second output signal output from the second microphone unit and outputs the synthesized signal. According to this aspect as well, it is possible to improve sensitivity in the bass range while achieving bi-directivity along the first axis and the second axis.

As one aspect of the sound collecting device described above, it is preferable that at least one of the first microphone unit and the second microphone unit is a bidirectional microphone unit having one diaphragm.

As one aspect of the sound collecting device described above, the first microphone unit is the bidirectional microphone unit, and the sound arriving at the first point is picked up by one surface of the diaphragm of the first microphone unit. and a second tube guiding sound arriving at said second point to the other side of the diaphragm of said first microphone unit. Further, it is preferred that the length of said first tube is substantially equal to the length of said second tube.

As another aspect of the sound collecting device described above, the first microphone unit includes a first omnidirectional microphone arranged at the first point and a second omnidirectional microphone arranged at the second point. an omnidirectional microphone; and a first generator that generates, as the first output signal, a signal corresponding to a difference between an output signal of the first omnidirectional microphone and an output signal of the second omnidirectional microphone. and the second microphone unit includes a third omnidirectional microphone arranged at the third point, a fourth omnidirectional microphone arranged at the fourth point, and the and a second generation unit configured to generate a signal corresponding to a difference between the output signal of the omnidirectional microphone 3 and the output signal of the fourth omnidirectional microphone as the second output signal. More preferably, the first point, the second point, the third point and the fourth point are provided on one straight line.

As one aspect of the sound collecting device described above, the first microphone unit and the second microphone unit are accommodated, and the first opening corresponding to the first point and the opening corresponding to the second point are provided. It is preferable to have a case provided with a second opening, a third opening corresponding to the third point, and a fourth opening corresponding to the fourth point.

As one aspect of the sound collecting device described above, the synthesizing unit includes a first low-pass filter to which the first output signal is input, a second low-pass filter to which the second output signal is input, and the an adder that adds the output signal of the first low-pass filter and the output signal of the second low-pass filter and outputs the output signal, wherein the cutoff frequency of the first low-pass filter is the second low-pass filter is preferably lower than the cutoff frequency of .

Further, as one aspect of an in-vehicle karaoke device, a first speaker arranged in a cabin of a vehicle, a second speaker facing the first speaker, and one of the first speaker and the second speaker The sound collecting device according to any one of the aspects described above, arranged in the vehicle compartment so that the first axis and the second axis intersect with the direction from one to the other, and the accompaniment sound of karaoke and a signal processing unit that adds an output signal of the sound collecting device to a sound signal and outputs the result to the first speaker and the second speaker.

Further, as one aspect of an in-vehicle karaoke device, a first speaker arranged in a cabin of a vehicle, a second speaker facing the first speaker, and one of the first speaker and the second speaker the sound collecting device according to any one of the above aspects, wherein at least one of the first axis and the second axis is arranged at the midpoint of the direction from one to the other so that the direction substantially overlaps; a signal processing unit that synthesizes a sound signal representing an accompaniment sound of karaoke and an output signal of the sound collecting device and outputs the result to the first speaker and the second speaker.

1A, 1B, 1C... vehicle-mounted karaoke device, 10A, 10B, 10C, 10D... sound pickup device, 20-1, 20-2... speaker, 30... signal processing section, 110A, 110A-1, 110A-2, 110B, 110B-1, 110B-2, 110B-3... microphone unit, 112... bidirectional microphone unit, 113-1, 113-2... omnidirectional microphone unit, 114, 114-1, 114-2... amplifier, 116 . . Subtractors 120A, 120B .

Claims (10)

A first microphone having bi-directionality along a first axis and picking up sounds arriving at first and second points spaced apart by a first distance on said first axis. a unit;
a third point having bi-directivity along a second axis substantially overlapping the first axis and spaced apart on the second axis by a second distance less than the first distance; a second microphone unit that picks up sound arriving at point 4;
a synthesizing unit for synthesizing a first output signal output from the first microphone unit and a second output signal output from the second microphone unit and outputting the synthesized signal;
A sound collecting device having 2. The sound collecting device according to claim 1, wherein at least one of said first microphone unit and said second microphone unit is a bidirectional microphone unit having one diaphragm. The first microphone unit is the bidirectional microphone unit,
a first tube that guides sound arriving at the first point to one side of a diaphragm of the first microphone unit;
a second tube that guides sound arriving at the second point to the other surface of the diaphragm of the first microphone unit;
3. The sound collecting device according to claim 2, comprising: 4. The sound collecting device of claim 3, wherein the length of said first tube is approximately equal to the length of said second tube. The first microphone unit includes a first omnidirectional microphone arranged at the first point, a second omnidirectional microphone arranged at the second point, and the first omnidirectional a first generation unit configured to generate, as the first output signal, a signal according to the difference between the output signal of the omnidirectional microphone and the output signal of the second omnidirectional microphone;
The second microphone unit includes a third omnidirectional microphone arranged at the third point, a fourth omnidirectional microphone arranged at the fourth point, and a third omnidirectional microphone. a second generator that generates a signal corresponding to the difference between the output signal of the omnidirectional microphone and the output signal of the fourth omnidirectional microphone as the second output signal,
The sound collecting device according to claim 1. 6. The sound collecting device according to claim 5, wherein said first point, said second point, said third point, and said fourth point are provided on one straight line. a first opening corresponding to the first point, a second opening corresponding to the second point, and a third opening accommodating the first microphone unit and the second microphone unit; 7. The sound collecting device according to any one of claims 1 to 6, comprising a case provided with a third opening corresponding to the point and a fourth opening corresponding to the fourth point. The synthesizing unit
a first low-pass filter to which the first output signal is input;
a second low-pass filter to which the second output signal is input;
an adder that adds and outputs the output signal of the first low-pass filter and the output signal of the second low-pass filter,
8. The sound collecting device according to any one of claims 1 to 7, wherein the cutoff frequency of said first lowpass filter is lower than the cutoff frequency of said second lowpass filter. a first speaker arranged in a vehicle compartment;
a second speaker facing the first speaker;
9. The first speaker and the second speaker are arranged in the vehicle compartment so that the direction from one to the other of the first speaker and the second speaker intersects the first axis and the second axis. A sound collecting device according to any one of
a signal processing unit that adds an output signal of the sound collecting device to a sound signal representing karaoke accompaniment sound and outputs the result to the first speaker and the second speaker;
In-vehicle karaoke device. a first speaker arranged in a vehicle compartment;
a second speaker facing the first speaker;
At least one of the first axis and the second axis is arranged at a midpoint in a direction from one of the first speaker and the second speaker to the other so as to substantially overlap with the direction, a sound collecting device according to any one of claims 1 to 8;
a signal processing unit that synthesizes a sound signal representing karaoke accompaniment sound and an output signal of the sound collecting device and outputs the synthesized signal to the first speaker and the second speaker;
In-vehicle karaoke device.

Images