KR100955328B1 - Apparatus and method for surround soundfield reproductioin for reproducing reflection - Google Patents

Abstract

The present invention relates to a stereoscopic sound field reproducing apparatus and method for reproducing reflected sound, and reproduces the stereoscopic sound field through the multichannel loudspeaker array as well as the direct sound, and reproduces the reflected sound by using a panning method or uses the respective loudspeakers. The present invention provides a stereoscopic sound field reproducing apparatus and method for reproducing reflection sound, which can provide a listener with a greater sense of presence and space by reproducing the reflection sound.

To this end, the present invention provides a stereoscopic sound field reproduction apparatus comprising: input means for receiving information for reproducing reflected sound; Signal processing means for selecting a loudspeaker for applying a panning method and calculating a reflected sound signal based on the received information for reproducing reflected sound; Signal processing means for positioning the calculated reflected sound signal on a virtual sound image according to the panning method; And reproducing means for reproducing the positioned reflected sound signal through the selected loudspeaker.

Reflected sound playback, stereoscopic sound field playback, sound field synthesis, reflected sound, panning method, GRA, inverse square law, constant power panning, direct sound

Description

Stereoscopic sound field reproducing apparatus and method therefor for reflection sound reproduction {APPARATUS AND METHOD FOR SURROUND SOUNDFIELD REPRODUCTIOIN FOR REPRODUCING REFLECTION}

The present invention relates to a stereoscopic sound field reproducing apparatus and method for reproducing a reflected sound, and more particularly, to reproduce a stereoscopic sound field through a multi-channel loudspeaker array as well as a direct sound, but using a panning method. The present invention relates to a stereoscopic sound field reproducing apparatus and method for reproducing a reflected sound, which can provide a listener with a greater sense of realism and a sense of space by reproducing a corresponding sound by using each loudspeaker.

The present invention is derived from a study conducted as part of the IT growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management Number: 2007-S-004-01, Title: Auto glasses-free 3D broadcasting Technology development].

Three-dimensional sound reproduction methods continue to evolve from traditional stereophony methods to discrete surround, binaural reproduction, and transaural reproduction. Source reproduction techniques such as 5.1-channel surround or 7.1-channel surround in two-channel stereo provide sound images that allow listeners to have a three-dimensional effect, but have a disadvantage in that they can be viewed.

Wave Field Synthesis (WFS) playback, which uses a loudspeaker array to solve this problem, can reproduce not only spherical waves but also planar wave sound fields, providing a constant three-dimensional image regardless of the listener's position. can do. In addition, the sound field synthesis reproduction method has attracted attention as a next generation audio reproduction method because there are many advantages such as being able to reproduce a moving sound source and locating a virtual sound source at any position in the listening space.

On the other hand, in the three-dimensional sound source reproduction method, not only arranging arbitrary sound sources in the space, but also sound field processing for providing listeners with a sense of space and a sense of presence as if they are in a specific space is also an important part. An apparatus capable of performing such signal processing is a sound field regenerator such as an artificial reverberator. The sound field player aims to replace the listening room acoustic environment with the acoustic environment desired by the listener. However, the listening environment in a general home can be compensated to some extent through the sound field tuning system.

However, sound field signal processing is required to artificially create an optimal acoustic environment for the sound source. This sound field reproduction technique requires a different signal processing technique than the reverberation processor used for recording. Most sound sources themselves contain reverberation. Therefore, when reverberation is added to the sound field player, reverberation is included twice, resulting in a long reverberation time and distortion of a tone.

In addition, in the case of a movie sound source, the sound field processing maximizes the sound field effect by controlling frequency characteristics instead of reverberation according to the movie genre, thus requiring a new approach. Therefore, the sound field reproduction technology for home theater is characterized by experience and artistry, not theory.

Currently, there is no standard of the optimal playback device or recording standard that can be directly applied to the sound field synthesis playback environment. Reproducing the surround sound field recording source in the sound field synthesis reproduction environment is also inevitable in terms of backward compatibility. This is a situation in which the installation of the sound field reproduction function is required to change freely to the sound environment desired by the listener.

In order to meet these demands, many studies to date have been conducted on the method of realizing virtual image positioning by reproducing only direct sound by sound field synthesis rendering. The conventional sound field reproduction method does not perform signal processing or reproduces audio obtained separately. For example, in the conventional sound reproducing system proposed by Delft University, each sound source is recorded in an undirected manner through a spot microphone in a recording studio. In addition, the sound reproducing system orchestrate these sound sources into a virtual sound source suitable for the location through the sound field synthesis rendering in the playback stage. The sound reproducing system records the reverberation and reflections of the entire recording studio via stereo microphones and renders them into a virtual stereo sound source located further away. This method was easy to reproduce the most popular stereo sound sources up to that time.

However, such a conventional sound reproducing technique can be built a complete sound field synthesis reproduction system only through sound field synthesis rendering and direct recording of an undirected sound source. In other words, the conventional sound reproducing technology is a situation where a complete sound field synthesis and reproducing system cannot be constructed through other sound sources.

In particular, the conventional sound field synthesis reproduction technology using a multichannel loudspeaker array is a technology using a multichannel loudspeaker array and regards all sound sources to be reproduced as point sources. In the related art, audio processing is performed by performing signal processing using the direction, time, and size information of the sound source for the listener position.

If a user wants to play a sound source in a specific space, not only the direct sound of the sound source but also the reflected sound generated by walls, floors, ceilings, etc. in the space may be played together to present more realistic audio to the listener. That is, instead of using the sound field synthesis method only for positioning the sound image of a specific sound source called direct sound, the reflected sound may be maximized if the signal processing is performed by the sound field synthesis reproduction method.

However, the number of meaningful reflections that can characterize a particular space can range from thousands to tens of thousands. Therefore, when all the reflected sound is processed by the sound field synthesis reproduction method, the amount of computation and time required for signal processing increases. That is, the conventional sound field synthesis reproduction technology using the multi-channel loudspeaker array has a problem that it is difficult to process the reflected sound by the sound field synthesis reproduction method, thereby maximizing the realism and the spatial feeling.

Therefore, the prior art as described above has a problem in that it is difficult to reproduce the reflected sound according to the sound field synthesis reproduction method of reproducing the audio using the loudspeaker array, thereby maximizing the realism and the spatial feeling to the listener. It is a subject of the present invention.

Therefore, the present invention reproduces the stereoscopic sound field through the multi-channel loudspeaker array as well as the direct sound, and reproduces the reflected sound using the panning method or the corresponding reflected sound using the respective loudspeakers, thereby providing a greater sense of presence to the listener. It is an object of the present invention to provide a three-dimensional sound field reproduction apparatus and method for the reflection sound reproduction that can provide a sense of space.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

In order to solve the above problems, it is possible to reproduce the stereoscopic sound field through the multichannel loudspeaker array as well as the direct sound, and to reproduce the reflected sound using a panning method or to reproduce the reflected sound using the respective loudspeakers. It features.

More specifically, the apparatus of the present invention is a stereoscopic sound field reproduction apparatus, comprising: input means for receiving information for reproducing reflection sound; Signal processing means for selecting a loudspeaker for applying a panning method and calculating a reflected sound signal based on the received information for reproducing reflected sound; Signal processing means for positioning the calculated reflected sound signal on a virtual sound image according to the panning method; And reproducing means for reproducing the positioned reflected sound signal through the selected loudspeaker.

On the other hand, another apparatus of the present invention, a stereoscopic sound field reproduction apparatus, comprising: input means for receiving information for reproducing the reflected sound; Signal processing means for identifying a loudspeaker corresponding to a reproduction angle of the reflected sound based on the received information for reproducing the reflected sound, and adjusting a spatial impulse response of the reflected sound according to the identified loudspeaker; Signal processing means for calculating a reflected sound signal from the spatial impulse response of the adjusted reflected sound and the sound source signal of the direct sound; And reproducing means for reproducing the calculated reflected sound signal through the identified loudspeaker.

On the other hand, the method of the present invention, in the stereoscopic sound field reproduction method, an input step of receiving information for the reflection sound reproduction; A signal processing step of selecting a loudspeaker for applying a panning scheme and calculating a reflected sound signal based on the received information for reproducing reflected sound; A signal processing step of positioning the calculated reflected sound signal on a virtual sound image according to the panning method; And a reproducing step of reproducing the positioned reflected sound signal through the selected loudspeaker.

Another method of the present invention provides a stereoscopic sound field reproduction method comprising: an input step of receiving information for reproducing a reflected sound; A signal processing step of identifying a loudspeaker corresponding to a reproduction angle of the reflected sound based on the received information for reproducing the reflected sound, and adjusting a spatial impulse response of the reflected sound according to the identified loudspeaker; A signal processing step of calculating a reflected sound signal from the spatial impulse response of the processed reflected sound and the sound source signal of the direct sound; And reproducing the calculated reflected sound signal through the identified loudspeaker.

As described above, the present invention reproduces the stereoscopic sound field through the multichannel loudspeaker array as well as the direct sound, and reproduces the reflected sound by using the panning method or by using the respective loudspeakers to reproduce the reflected sound. It has the effect of providing a great sense of presence and space.

That is, according to the present invention, only the direct sound is reproduced without reproducing both the reflected sound and the direct sound according to the sound field synthesis reproducing method, and the reflected sound is reproduced in the three-dimensional sound field by using the panning method, thereby reducing the amount of calculation and calculation time, and in terms of power. Not all loudspeakers are driven, which makes it possible to reproduce reflections more efficiently. In addition, the present invention by using the respective loudspeakers to reproduce the reflection sound, the rendering process for the reproduction of the reflection sound can be omitted, and the amount of computation and operation time can be reduced, and the tone change that can be generated through the rendering for the reflection sound reproduction There is an effect that can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an embodiment of a stereoscopic sound field reproducing apparatus using sound field synthesis for better understanding of the present invention.

As shown in FIG. 1, the stereoscopic sound field reproducing apparatus 100 using sound field synthesis for the understanding of the present invention includes an input unit 110, a signal processing unit 120, and a reproducing unit 130.

Hereinafter, each component of the stereoscopic sound field reproducing apparatus 100 will be described.

The input unit 110 includes loudspeaker array information (for example, information about the arrangement such as the position and spacing of the loudspeaker array), sound source position information (for example, information about a position such as an angle of the sound source with respect to the listening position). , And a sound source signal to be positioned.

The signal processing unit 120 obtains a distance between each loudspeaker and a sound source position from the loudspeaker array information and the sound source position information received from the input unit 110, and applies the distance to the loudspeaker driving function to provide a sound pressure signal in the form of an impulse response. Obtain That is, the signal processor 120 calculates a sound pressure signal (sound) to be emitted by each loudspeaker by applying the loudspeaker array information and the sound source position information to Equation 1 below, that is, the loudspeaker driving function. In addition, the signal processor 120 obtains a sound pressure signal to be emitted by each loudspeaker in the form of an impulse response for each loudspeaker in consideration of delay and gain.

은 어레이를 구성하는 라우드스피커 중 n 번째 라우드스피 커가 방사하는 오디오 신호 구동 함수,

는 가상 음원,

는 크기에 대한 가중치,

는 라우드스피커의 지향성으로 음압에 웨이팅(weighting)을 주는 성분,

는 수직거리에 대한 가상음원과 n 번째 라우드스피커 사이의 거리의 비율,

는 고주파 증폭 이퀄라이징,

는 가상음원과 n 번째 라우드스피커 사이의 거리에 의해 발생하는 전달 시간을 나타낸다. 또한, 라우드스피커가 선배열을 이루고 있으므로 가상음원은 선음원으로 가정했을 때,

는 하나의 원통파(cylindrical wave)의 확산을 나타낸다.here,

Is the audio signal driving function emitted by the nth loudspeaker of the loudspeakers

Virtual sound source,

Is the weight for size,

Is a loudspeaker's directivity that gives weight to the sound pressure,

Is the ratio of the distance between the virtual sound source and the nth loudspeaker to the vertical distance,

High frequency amplification equalizing,

Denotes the propagation time caused by the distance between the virtual sound source and the nth loudspeaker. In addition, since the loudspeakers form a pre-array, when the virtual sound source is assumed to be a line sound source,

Denotes the spread of one cylindrical wave.

Equation 1 relates to a sound source rendering theory using sound field synthesis based on the Huygenss principle and the Kirchhoff-Helmholtz equation. The sound source rendering theory using sound field synthesis distinguishes the area where virtual sound sources are played and the area where n physical loudspeaker arrays emit sound through The Ralyleighs representation theorem. It is about the speaker drive function that can be obtained.

In addition, the signal processing unit 120 performs Fourier transform on the sound pressure signal of the impulse response type obtained through Equation 1, and then the sound source signal received from the input unit 110 and the Fourier transformed impulse response type. The sound pressure signal is convolved to calculate a sound source signal rendered by the number of loudspeakers, that is, a driving signal of each loudspeaker. That is, the signal processor 120 performs a convolution operation on the sound source signal and the reflected sound signal. This is to find all driving signals that the n loudspeakers should emit in order to virtually position one sound source signal in the listening space.

The reproducing unit 130 reproduces the driving signal of each loudspeaker calculated by the signal processing unit 120 through the corresponding loudspeaker among the n loudspeakers.

2 is an exemplary diagram of a reflection sound distribution considering only a sound field on a plane.

The stereoscopic sound field reproducing apparatus 100 uses the initial reflection sound of the space 210 to be simulated. In this case, the stereoscopic sound field reproducing apparatus 100 may obtain the reflected sound through the microphone array implemented in various ways. The stereoscopic sound field reproducing apparatus 100 reproduces sound in the horizontal plane of the loudspeaker height surrounding the listener 200, and does not consider the vertical plane. Reflected sound 201 considering only the sound field on the plane is distributed in all directions 360 degrees around the listener, as shown in FIG.

3 is a view illustrating a comparison of the magnitudes of the direct sound and the reflected sound over time.

Looking at the reflection sound 32 distributed in all directions described in FIG. 2 in terms of a sample to be reproduced in each loudspeaker, as shown in FIG. 3, the magnitude of the direct sound 31 and the reflection sound 32 over time. Is different. Therefore, assuming that all of these samples are one point sound source, the stereoscopic sound field reproducing apparatus 100 can render not only the direct sound 31 but also the reflected sound 32 in a sound field synthesis method.

Table 1 shows characteristics of the reflection sound 32 shown in FIG. The reflection sound signal of the specific space has the delay time information, sound pressure, and the angle which is incident on the basis of the listener after the direct sound 31 is reproduced. The stereoscopic sound field reproducing apparatus 100 receives the reflection sound signals of the three specific spaces and performs the sound field synthesis rendering process on the received reflection sound signals. Accordingly, the stereoscopic sound field reproducing apparatus 100 reproduces each reflected sound 32 regarded as a point sound source.

4 to 6 are diagrams illustrating an arrangement of loudspeakers applied to a stereoscopic sound field reproducing apparatus using sound field synthesis.

Based on the position of the listener 200, the loudspeakers 41, 51, 61 may have various types of arrangements. As shown in FIGS. 4 to 6, the loudspeakers 41, 51, and 61 may have a circular arrangement, a rectangular quadrangular arrangement, or a 'c' shape arrangement. The signal processor 120 obtains a driving signal to which n loudspeakers should radiate according to the loudspeaker array information.

7 is a flowchart illustrating an embodiment of a stereoscopic sound field reproduction method using sound field synthesis to assist in understanding the present invention.

First, the input unit 110 may include loudspeaker array information (for example, information about the arrangement of the loudspeaker array and its spacing), sound source position information (for example, a position such as an angle of the sound source with respect to the listening position). Information), and a sound source signal to be positioned (step 702).

The signal processor 120 calculates the sound pressure signal in the form of an impulse response by applying the loudspeaker array information and the position information of the sound source input from the input unit 110 to the loudspeaker driving function (704). Subsequently, the signal processor 120 performs a Fourier Transform on the sound pressure signal in the form of an impulse response.

Thereafter, the signal processor 120 calculates a driving signal to be emitted by each loudspeaker by convolving the sound source signal to be positioned by the input unit 110 with the Fourier transformed sound pressure signal (706).

The playback unit 130 reproduces the driving signal of each loudspeaker calculated by the signal processing unit 120 through the corresponding loudspeaker among the n loudspeakers arranged (708).

Hereinafter, a first embodiment of a stereoscopic sound field reproduction apparatus for reflecting sound reproduction according to the present invention will be described with reference to FIGS. 8 to 13. The first embodiment of the stereoscopic sound field reproducing apparatus according to the present invention reproduces the reflection sound formed 360 degrees in all directions by using the panning method.

First, a panning technique will be described before describing a first embodiment of a stereoscopic sound field reproduction apparatus for reproducing reflection sound according to the present invention.

The stereoscopic sound field reproducing apparatus 100 using the sound field synthesis applied to the present invention described above reproduces 1,000 to 10,000 reflected sounds in n speakers to realistically reproduce the reflected sound of a specific space. Therefore, the stereoscopic sound field reproducing apparatus 100 must perform (1,000 to 10,000) x n rendering processes. At this time, looking at the structure of the reflection sound to be reproduced, as shown in Figure 2, the reflection sound for the direct sound produced by the wall, etc. is heard in 360 degrees around the listener located in the center. In order to reproduce the plurality of reflection sounds, the stereoscopic sound field reproducing apparatus 100 must process a plurality of calculation amounts.

Here, the panning method is used to orient the virtual sound image in the stereophonic reproduction method. The panning method is a method of disposing a virtual speaker, that is, a virtual sound source, between two physical speakers by adjusting the radiant power of two speakers. In addition, the panning method may position the sound source at any position between the two speakers. By applying this panning method, the reverberation of a specific space is realistically reproduced. In other words, reverberation refers to the characteristic reflection of sound in a specific space. For example, if a singer is singing in a concert hall, the voice of the singer on the stage, the reflection of the direct sound being reflected on all four sides of the wall, will be heard by the listener in the audience. The listener hears the reflections in 360 degrees around him. The panning method can use this phenomenon to provide the listener with direction and presence. In other words, the direct sound indicates the direction to the listener, and the reflected sound provides a sense of reality while reinforcing the direct sound.

8 is a configuration diagram of a first embodiment of a stereoscopic sound field reproducing apparatus for reflecting sound reproduction according to the present invention.

As shown in FIG. 8, the stereoscopic sound field reproducing apparatus 800 for reproducing the reflected sound according to the first exemplary embodiment of the present invention includes an input unit 810, a signal processor 820, a signal processor 830, and a reproducer. 840.

The input unit 810 may be configured such as loudspeaker arrangement information, sound source position information of a reflection sound to a sound source position to be positioned from a listener position, a spatial impulse response of a reflection sound to a space to be reproduced, and a direct sound source signal. Information for reflex sound reproduction ”is input.

The signal processor 820 analyzes the sound source position information and the loudspeaker arrangement information from the “information for reproducing the sound” received from the input unit 810 to check the angle of each loudspeaker with respect to the listener position and the distance from the listener. do. In addition, the signal processor 820 selects a plurality of loudspeakers for applying a panning method by checking a sound source position of the reflection sound and an angle and a distance between the loudspeakers. In this case, the signal processor 820 may select different loudspeakers according to the arrangement of the loudspeakers in order to apply the panning method.

For example, the signal processor 820 selects loudspeakers located at 30, 110, 250, and 330 degrees from the listening position. Of course, this corresponds to the case where the multi-channel loudspeaker array described later in FIG. 10 is arranged in a circular shape. In the case of a rectangular array having a straight array in four directions, which will be described later with reference to FIG. 11, two loudspeakers and eight loudspeakers are selected for each array. Alternatively, when the loudspeaker array described later in FIG. 12 takes the form of a letter 'c', a total of six loudspeakers are selected. On the other hand, since the loudspeaker array can be implemented in a variety of arrangements, such as triangle, rhombus, etc. as needed, the loudspeaker is selected according to the arrangement.

The signal processor 820 calculates the reflected sound signal by convolving the spatial impulse response of the reflected sound with respect to the space to be reproduced and the sound signal of the direct sound among the " information for playing the reflected sound " received from the input unit 810.

Meanwhile, the signal processor 830 analyzes the angular component of the reflected sound signal calculated by the signal processor 820 and allocates the reflected sound signal to a pair of loudspeakers to position the virtual sound image. In this case, the signal processing unit 830 uses a constant power panning law method using a pair of loudspeakers and an inverse square law that corrects the virtual sound image according to a distance. It locates on an imaginary sound.

That is, the signal processing unit 830 analyzes the angle information of the calculated reflection sound signal and allocates the reflection sound signal to the pair of loudspeakers selected by the signal processing unit 820 in order to apply the panning method. Here, the reflected sound signal has angular components corresponding to the front, side, and rear surfaces. At this time, the constant power panning method is applied through a pair of loudspeakers at the same distance from the listener, and the virtual sound image produced by the panning method is also located at the same distance. Therefore, as shown in Figs. 11 and 12, when the loudspeakers are in a linear arrangement, the pair of loudspeakers at the edge is farthest from the listener and the remaining speakers are relatively close to the listener. . Accordingly, the signal processing unit 830 aligns the virtual sound image to be located at a relatively close distance to the listener at a position according to the panning method by using an inverse square law.

The reproducing unit 840 reproduces the reflected sound signal positioned on the virtual sound by the signal processing unit 830 through a pair of loudspeakers.

9 is a diagram illustrating an embodiment of a panning method applied to the present invention.

As shown in Fig. 9, the panning method is performed through a pair of loudspeakers consisting of two loudspeakers. The stereoscopic sound field reproducing apparatus 800 according to the present invention reproduces the reflected sound as a virtual sound source by using panning between the left speaker 91 and the right speaker 92 in the case of the front surface. In addition, the stereoscopic sound field reproducing apparatus 800 has a left speaker 91, a left surround speaker 93, a right speaker 92 and a right surround (left and right), respectively, in the case of the side surface. Right Surround) panning using speakers 94. Also, the stereoscopic sound field reproducing apparatus 800 pans the reflected sound using the left surround speaker 93 and the right surround speaker 94 in the case of the rear surface. Accordingly, the stereoscopic sound field reproducing apparatus 800 simulates the reflection sound generated in 360 degrees around the listener.

10 to 12 are diagrams illustrating an arrangement of loudspeakers applied to the first embodiment of the present invention.

First, as shown in FIG. 10, when the multi-channel loudspeaker array is arranged in a circular shape, the front 1021, the right side 1022, the rear 1010, With respect to the left side 1024, when the signal processing unit 820 calculates a driving signal for the direct sound according to the sound field synthesis reproduction method, the reproducing unit 840 transmits the calculated driving signal to the loudspeakers installed on each side. Playback through 1011 to 1014).

Meanwhile, the signal processor 830 analyzes the angular component of the reflected sound signal calculated by the signal processor 820 and allocates the reflected sound signal to a pair of loudspeakers to position the virtual sound image. That is, the signal processing unit 830 uses the pair of loudspeakers 1001 to 1004 positioned at 30 degrees, 110 degrees, 250 degrees, and 330 degrees from the listening position to reflect the reflected sound signal onto the virtual sound. Orient. For example, the signal processing unit 830 uses the 330 degree loudspeaker 1001 and the 30 degree loudspeaker 1002 to reproduce the reflected sound signal on the front surface 1021. Is located on the virtual sound. Also, the signal processing unit 830 uses the 30s loudspeaker 1002 and the 110s loudspeaker 1003 for the reflection sound reproduction on the side surfaces 1022 and 1024, and the left side 1024. ) Uses the 330 degree loudspeaker 1001 and the 250 degree loudspeaker 1004 to position the reflection sound signals of each side onto the virtual sound. In addition, the signal processing unit 830 orients the reflected sound signal on the rear surface by using the loudspeaker 1003 at 110 degrees and the loudspeaker 1004 at 250 degrees to reproduce the reflected sound on the rear surface 1023 on the virtual sound.

Secondly, as shown in FIG. 11, when the multi-channel loudspeaker array is arranged in a rectangular quadrangle, the front face 1121, the right side 1122, and the rear face 1123 based on the listener 200 are described. , And the left side 1124, when the signal processing unit 820 calculates a drive signal for the direct sound according to the sound field synthesis reproduction scheme, the playback unit 840 outputs the calculated drive signal corresponding to each side of the loudness. Playback through the speakers 1111 to 1114 is performed.

On the other hand, the signal processing unit 830 orients the reflected sound signal on the virtual sound using eight loudspeakers 1101 to 1108 in total, with two loudspeakers per edge from the listening position. That is, the signal processing unit 830 uses two loudspeakers "1102" and "1103" in the case of the front surface 1121, and two loudspeakers "1104" and "1105" in the case of the right side 1122. Reflectance signal using two loudspeakers " 1106 " and " 1107 " for the rear face 1123, and two loudspeakers " 1108 " and " 1101 " Is located on the virtual sound.

Third, as shown in FIG. 12, when the multi-channel loudspeaker array is arranged in a 'c' shape, the front surface 1221 based on the listener 200, the right side 1222, and the rear side With respect to the 1223 and the left side 1224, when the signal processing unit 820 calculates a drive signal for the direct sound according to the sound field synthesis reproduction method, the reproduction unit 840 transmits the calculated drive signal to each side. Playback is carried out through the corresponding loudspeakers 1211-1213.

On the other hand, the signal processing unit 830 orients the virtual sound image using the six loudspeakers 1201 to 1206 in total, with two loudspeakers at the edge from each listening position. That is, the signal processing unit 830 uses two loudspeakers “1202” and 1203 for the front surface 1221, and uses two loudspeakers “1204” and “1205” for the right side 1222. In the case of the rear surface 1223, two loudspeakers "1205" and "1206" are used, and in the case of the left side 1224, two loudspeakers "1206" and "1201" are used to simulate the reflection sound signal. Orient to the sound of.

On the other hand, the loudspeaker array may be implemented in a variety of arrangements, such as triangles, rhombuses.

13 is a flowchart of a first embodiment of a stereoscopic sound field reproduction method for reflection sound reproduction according to the present invention.

First, the input unit 810 may include loudspeaker arrangement information, sound source position information of a reflection sound relative to a sound source position to be positioned from a listener's position, a spatial impulse response of a reflection sound to a space to be reproduced, and a direct sound source signal. "Information for reproducing the reflected sound" is input (1302).

In addition, the signal processor 820 uses the sound source position information and the loudspeaker array information of the reflected sound among the "information for reproducing the sound" received from the input unit 810 to determine the angle of each loudspeaker with respect to the listener position and the distance from the listener. Then, the loudspeaker for the panning method is selected (1304). In this case, the signal processor 820 selects different loudspeakers according to the arrangement of the loudspeakers in order to apply the panning method.

After the loudspeaker for the panning method is selected as described above, the signal processing unit 820 receives the spatial impulse response and the direct sound of the reflected sound for the space to be reproduced from the “information for reproducing the sound” received from the input unit 810. The reflected sound signal is convolved to calculate the reflected sound signal (1306).

Thereafter, the signal processor 830 analyzes the angular component of the reflected sound signal calculated by the signal processor 820 and allocates the reflected sound signal to the pair of loudspeakers to position the reflected sound signal on the virtual sound. In this case, in order to apply the panning method, the signal processing unit 830 orients the reflected sound signal calculated using the constant power panning and inverse square law on the virtual sound (1308).

The reproduction unit 840 reproduces the reflected sound signal positioned on the virtual sound by the signal processing unit 830 through a pair of loudspeakers (1310).

Hereinafter, a second embodiment of a stereoscopic sound field reproducing apparatus for reflecting sound reproduction according to the present invention will be described with reference to FIGS. 14 to 18. A second embodiment of the stereoscopic sound field reproducing apparatus according to the present invention relates to a method of reproducing corresponding reflection sounds by using a plurality of loudspeakers already installed for sound field synthesis reproduction.

First, before describing the second embodiment of the stereoscopic sound field reproduction apparatus for reproducing the reflected sound according to the present invention, the first embodiment according to the present invention will be described as follows.

As described above, the stereoscopic sound field reproducing apparatus 800 according to the first embodiment of the present invention may reproduce the sound even at a position where the loudspeaker is not physically present by using the panning method. To this end, the stereoscopic sound field reproducing apparatus 800 is a pair of two loudspeakers, and as shown in FIG. 9, in the front case, panning between the left speaker 91 and the right speaker 92 is performed. Reproduces the reflected sound as a virtual sound source, and pans using the left and right surround speakers 91, the left surround speaker 93, the right speaker 92 and the right surround speaker 94 in the case of the side, In this case, by reflecting the reflected sound using the left surround speaker 93 and the right surround speaker 94, it is possible to simulate the reflected sound distributed 360 degrees around the listener.

Here, in the stereoscopic sound field reproducing apparatus 800 according to the first embodiment of the present invention, the virtual sound image may be biased toward the speaker even when constant power panning law is applied. In this case, the stereoscopic sound field reproducing apparatus 800 may have a virtual sound image biased toward the speaker, and thus the sound position may not be correct or the tone may be changed due to power adjustment and combination.

Therefore, the stereoscopic sound field reproducing apparatus 1400 according to the second embodiment of the present invention uses an already installed loudspeaker array to reproduce the reflected sound signal in all directions of 360 degrees surrounding the listener. Here, the reflected sound signal has a time at which the reflected sound signal is reproduced after the direct sound is reproduced, the sound pressure, and the angle incident upon the listener. That is, since three pieces of information of the reflection sound signal to be reproduced are previously contained as shown in [Table 1], the stereoscopic sound field reproducing apparatus 1400 according to the second embodiment of the present invention has angle information of the three pieces of information of the reflection sound signal. By using this function, the reflected sound signal is assigned to each loudspeaker and played back. Since the loudspeaker array surrounds the listener, the 3D sound field reproducing apparatus 1400 directly plays back the loudspeaker at the incident angle without performing a separate rendering process. This method is called a GRA (Grouped Reflection Algorithm) method.

14 is a configuration diagram of a second embodiment of a stereoscopic sound field reproducing apparatus for reflecting sound reproduction according to the present invention.

As shown in FIG. 14, the stereoscopic sound field reproducing apparatus 1400 for reproducing the reflected sound according to the second exemplary embodiment of the present invention includes an input unit 1410, a signal processing unit 1420, a signal processing unit 1430, and a reproducing unit. 1440.

The input unit 1410 receives loudspeaker arrangement information, sound source position information of a reflection sound relative to a sound source position to be positioned from a listener position, a spatial impulse response of a reflection sound to a space to be reproduced, and a direct sound source signal.

The signal processing unit 1420 analyzes the loudspeaker array information received from the input unit 1410 and the sound source position information of the reflection sound with respect to the sound source position to be positioned from the position of the listener, and the angle between each loudspeaker and each loudspeaker from the loudspeaker. Find the distance to the position of the reflection sound to be reproduced. The signal processing unit 1420 checks the loudspeaker corresponding to the reproduction angle of the reflected sound using the obtained reproduction angle of each loudspeaker and the distance between each loudspeaker and the sound source position of the reflected sound.

Here, the process of identifying the loudspeaker corresponding to the reproduction angle of the reflected sound will be described in more detail.

If the loudspeaker located in front of the listener is viewed as a loudspeaker in the 0 degree position, each loudspeaker is made of a loudspeaker array corresponding to 360 degrees by increasing a clockwise angle. If the loudspeaker array is circular and the listener is centered, the loudspeaker is placed every k degrees and the distance from the listener is all the same. The signal processing unit 1420 analyzes the angle information of the sound source position of the reflected sound and compares the playback angle of each loudspeaker consisting of multiples of k degrees and k degrees and the angle of reflection of the reflected sound to compare the reproduction angle of the reflected sound to the multiple of several k degrees. Determine if applicable and select the loudspeaker associated with the multiple of the k degrees. In this case, if the reproduction angle of the reflected sound does not correspond to a multiple of the k-degree angle, the signal processing unit 1420 may determine the loudspeaker having the smaller angle difference among the adjacent loudspeakers based on the reproduction angle of the reflected sound.

In addition, the signal processing unit 1420 may match at least one of the angle or power of the spatial impulse response of the reflected sound with respect to the space to be reproduced received from the input unit 1410 to match the angle multiple of each loudspeaker and the distance to the sound source position of the reflected sound. Adjust

Meanwhile, the signal processor 1430 convolves the spatial impulse response adjusted by the signal processor 1420 and the sound source signal of the direct sound received by the input unit 1410 to calculate a reflection sound signal to be allocated to each loudspeaker.

The reproduction unit 1440 reproduces the reflected sound signal calculated by the signal processing unit 1430 through each of the loudspeakers identified by the signal processing unit 1420.

15 to 17 are diagrams illustrating an arrangement of loudspeakers applied to the second embodiment of the present invention.

Referring to FIG. 15, when the loudspeaker array applied to the second embodiment of the present invention has a circular shape, the listener 200 is located at the center and the loudspeaker is disposed every k degrees. The distances between the speakers are all the same.

As described above, the signal processing unit 1420 analyzes the angle information of the sound source position of the reflected sound to determine which k degree multiple of k degrees and multiples of k degrees corresponds. At this time, the signal processing unit 1420 determines the angle of the reflected sound that is not exactly a multiple of k degrees and k degrees as an angle close to the numerical value of the adjacent angles.

In addition, as shown in Figure 16, the arrangement of the loudspeakers applied to the second embodiment of the present invention may be arranged in a rectangular shape. In Fig. 15, the loudspeaker array is circular and the listener is centered, so that the distance between the loudspeaker and the listener is the same every k degrees. However, in a loudspeaker array arranged at right angles, the distance between the loudspeaker and the listener is not equal at every k degrees.

In addition, as shown in FIG. 17, the loudspeaker array applied to the second embodiment of the present invention may be arranged in a 'c' shape without any one of four sides of a rectangular quadrangle.

On the other hand, the loudspeaker array applied to the second embodiment of the present invention may be made in a variety of arrangements, such as triangle, rhombus. In addition, the listening position of the listener 200 may also be biased to one side, not just the center of the loudspeaker arrangement. Therefore, the sound pressure for each angle of the reflected sound signal may be readjusted based on the loudspeaker array information and the sound source position information.

18 is a flowchart of a second embodiment of a stereoscopic sound field reproduction method for reflection sound reproduction according to the present invention.

First, the input unit 1410 receives loudspeaker arrangement information, sound source position information of a reflection sound for a sound source position to be positioned from a listener position, a spatial impulse response of a reflection sound to a space to be reproduced, and a direct sound source signal. (1802).

Thereafter, the signal processing unit 1420 analyzes the loudspeaker array information received from the input unit 1410 and the sound source position information of the reflection sound with respect to the sound source position to be positioned from the position of the listener, and the angle between each loudspeaker and each loudspeaker. The distance from the reflected sound position to the playback to is determined. The signal processing unit 1420 checks the loudspeaker corresponding to the reproduction angle of the reflected sound by using the reproduction angle of each loudspeaker and the distance between each loudspeaker and the sound source position of the reflected sound (1804).

In addition, the signal processing unit 1420 may match at least one of the angle or power of the spatial impulse response of the reflected sound with respect to the space to be reproduced received from the input unit 1410 to match the angle multiple of each loudspeaker and the distance to the sound source position of the reflected sound. Adjust (1806). In this case, if the reproduction angle of the reflected sound does not correspond to a multiple of the k-degree angle, the signal processing unit 1420 may determine the loudspeaker having the smaller angle difference among the adjacent loudspeakers based on the reproduction angle of the reflected sound.

Thereafter, the signal processing unit 1430 convolves the spatial impulse response adjusted by the signal processing unit 1420 and the sound source signal of the direct sound received from the input unit 1410 to calculate a reflection sound signal to be allocated to each loudspeaker ( 1808).

Thereafter, the reproduction unit 1440 reproduces the reflected sound signal calculated by the signal processing unit 1430 through the respective loudspeakers identified by the signal processing unit 1420 (1810).

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

1 is a configuration diagram of an embodiment of a stereoscopic sound field reproducing apparatus using sound field synthesis to help understanding of the present invention;

2 is an exemplary diagram of a reflection sound distribution considering only a sound field on a plane;

3 is a view comparing the magnitudes of the direct sound and the reflected sound over time;

4 to 6 are diagrams illustrating an arrangement of loudspeakers applied to a stereoscopic sound field reproduction apparatus using sound field synthesis;

7 is a flow chart of an embodiment of a stereoscopic sound field reproducing method using sound field synthesis for the understanding of the present invention;

8 is a configuration diagram of a first embodiment of a stereoscopic sound field reproduction apparatus for reflecting sound reproduction according to the present invention;

9 is a diagram illustrating an embodiment of a panning method applied to the present invention;

10 to 12 is an illustration of the arrangement of the loudspeakers applied to the first embodiment of the present invention,

13 is a flowchart of a first embodiment of a stereoscopic sound field reproduction method for reflection sound reproduction according to the present invention;

14 is a configuration diagram of a second embodiment of a stereoscopic sound field reproduction apparatus for reflecting sound reproduction according to the present invention;

15 to 17 is an illustration of the arrangement of the loudspeakers applied to the second embodiment of the present invention,

18 is a flowchart of a second embodiment of a stereoscopic sound field reproduction method for reflection sound reproduction according to the present invention.

* Explanation of symbols for the main parts of the drawings

800, 1400: stereoscopic sound field reproduction apparatus 810, 1410: input unit

820, 1430: signal processor 830, 1420: signal processor

840, 1440: playback unit

Claims (24)

delete In the stereoscopic sound field reproduction device, Input means for receiving information for reproducing the reflected sound; Signal processing means for selecting a loudspeaker for applying a panning scheme and calculating a reflected sound signal based on the information for reproducing the reflected sound received from the input means; Analyzing the angular component of the reflected sound signal calculated by the signal processing means according to the panning method, assigning the calculated reflected sound signal to a pair of loudspeakers, and processing the signal to align the calculated reflected sound signal on the virtual sound image. Way; And Reproducing means for reproducing the reflected sound signal orientated by said signal processing means through said selected loudspeaker; Stereoscopic sound field reproduction apparatus for reproducing the reflected sound comprising a. The method of claim 2, The signal processing means, The calculated reflection sound signal is a virtual sound image using a constant power panning law method using the pair of loudspeakers and an inverse square law that corrects a virtual sound image according to a distance. A stereoscopic sound field reproducing apparatus for reproducing a reflected sound, wherein the stereo sound is positioned on the. The method according to claim 2 or 3, The input means, Receiving loudspeaker array information, reflection source location information, reflection impulse spatial impulse response, and direct sound source signal, The signal processing means, A plurality of loudspeakers for applying the panning method are selected based on the received loudspeaker array information and the sound source position information of the reflected sound, and the spatial impulse response of the received reflected sound and the sound source signal of the direct sound are selected. A stereoscopic sound field reproducing apparatus for reproducing a reflected sound, characterized by convolutional to calculate a reflected sound signal. The method of claim 4, wherein The signal processing means, Selecting the plurality of loudspeakers for applying the panning method by confirming the angles and distances between the loudspeaker positions and the respective loudspeakers from the received loudspeaker arrangement information and the sound source position information of the reflected sound. A stereoscopic sound field reproduction apparatus for reflex sound reproduction. The method of claim 5, The signal processing means, In order to apply the panning method, a three-dimensional sound field reproduction apparatus for reproducing sound, characterized in that different loudspeakers are selected according to the arrangement of the loudspeakers. In the stereoscopic sound field reproduction device, Input means for receiving information for reproducing the reflected sound; Signal processing means for identifying a loudspeaker corresponding to the reproduction angle of the reflected sound based on the information for reproducing the reflected sound received from the input means, and adjusting a spatial impulse response of the reflected sound according to the identified loudspeaker; Signal processing means for calculating a reflected sound signal from the spatial impulse response of the reflected sound adjusted by the signal processing means and the sound source signal of the direct sound; And Reproducing means for reproducing the reflected sound signal calculated by said signal processing means through said identified loudspeaker Stereoscopic sound field reproduction apparatus for reproducing the reflected sound comprising a. The method of claim 7, wherein The input means, Receiving loudspeaker array information, sound source position information of the reflected sound, spatial impulse response of the reflected sound, and sound source signal of the direct sound, The signal processing means, Identifying the loudspeaker corresponding to the reproduction angle of the reflected sound based on the received loudspeaker array information and the sound source position information of the reflected sound, and adjusting the spatial impulse response of the received reflected sound according to the identified loudspeaker A stereoscopic sound field reproduction apparatus for reflex sound reproduction. The method of claim 8, The signal processing means, The loudspeaker corresponding to the reproduction angle of the reflected sound is identified using the reproduction angle of each loudspeaker obtained from the received loudspeaker array information and the sound source position information of the reflected sound and the 'distance between the respective loudspeaker and the sound source positions of the reflected sound'. A stereoscopic sound field reproduction apparatus for reproducing reflection sound, characterized in that. The method of claim 9, The signal processing means And reproducing the loudspeaker corresponding to the reproducing angle of the reflected sound by comparing the reproducing angle of each loudspeaker having a multiple of a predetermined angle and the reproducing angle of the reflected sound. The method of claim 10, The signal processing means, If the reproducing angle of the reflected sound does not correspond to a multiple of the predetermined angle, identifying the loudspeaker whose angle difference is smaller among the adjacent loudspeakers based on the reproducing angle of the reflected sound with the loudspeaker corresponding to the reproducing angle of the reflected sound. A stereoscopic sound field reproduction apparatus for reflex sound reproduction. The method of claim 11, The signal processing means, Adjusting the angle or power for the spatial impulse response of the reflection sound in accordance with the identified loudspeaker, Stereoscopic sound field reproduction apparatus for the reflection sound reproduction. In the stereoscopic sound field reproduction method, An input step of receiving information for reproducing the reflected sound; A signal processing step of selecting a loudspeaker for applying a panning scheme and calculating a reflected sound signal based on the information for reproducing the reflected sound received in the input step; A signal processing step of positioning the reflected sound signal calculated in the signal processing step on a virtual sound image according to the panning method; And A reproducing step of reproducing the reflected sound signal positioned in the signal processing step through the selected loudspeaker Stereo sound field reproduction method for reflection sound reproduction comprising a. The method of claim 13, The signal processing step, Analyzing the angular component of the calculated reflection sound signal and assigning the calculated reflection sound signal to a pair of loudspeakers to position the calculated reflection sound signal on a virtual sound; . The method of claim 14, The signal processing step, The calculated reflection sound signal is a virtual sound image using a constant power panning law method using the pair of loudspeakers and an inverse square law that corrects a virtual sound image according to a distance. And stereoscopic sound field reproduction method for reflection sound reproduction. The method according to any one of claims 13 to 15, The input step, Receiving loudspeaker array information, reflection source location information, reflection impulse spatial impulse response, and direct sound source signal, The signal processing step, A plurality of loudspeakers for applying a panning method is selected based on the received loudspeaker array information and the sound source position information of the reflected sound, and convolution of the received spatial impulse response and the direct sound source signal. And a reflection sound signal is calculated so as to calculate a reflection sound signal. The method of claim 16, The signal processing step, Selecting the plurality of loudspeakers for applying a panning method by confirming an angle and a distance between the sound source positions of the reflected sound and the respective loudspeakers from the received loudspeaker array information and the sound source position information of the reflected sound; A stereoscopic sound field reproduction method for reflection sound reproduction. The method of claim 17, The signal processing step, In order to apply a panning method, a stereo sound field reproduction method for reflection sound reproduction, characterized in that different loudspeakers are selected according to the arrangement of the loudspeakers. delete In the stereoscopic sound field reproduction method, An input step of receiving loudspeaker array information, sound source position information of a reflected sound, a spatial impulse response of the reflected sound, and a sound source signal of a direct sound; The loudspeaker corresponding to the reproduction angle of the reflected sound is identified based on the loudspeaker array information received in the input step and the sound source position information of the reflected sound, and the spatial impulse response of the received reflected sound is determined according to the identified loudspeaker. Signal processing step adjusting; A signal processing step of calculating a reflected sound signal from the spatial impulse response of the reflected sound processed in the signal processing step and the sound source signal of the direct sound; And A reproducing step of reproducing the reflected sound signal calculated in the signal processing step through the identified loudspeaker Stereo sound field reproduction method for reflection sound reproduction comprising a. The method of claim 20, The signal processing step, The loudspeaker corresponding to the reproduction angle of the reflected sound is identified using the reproduction angle of each loudspeaker obtained from the received loudspeaker array information and the sound source position information of the reflected sound and the 'distance between the respective loudspeaker and the sound source positions of the reflected sound'. A stereoscopic sound field reproduction method for reflection sound reproduction, characterized in that the. The method of claim 21, The signal processing step And reproducing the loudspeaker corresponding to the reproducing angle of the reflected sound by comparing the reproducing angle of the respective loudspeakers having a multiple of a predetermined angle and the reproducing angle of the reflected sound. The method of claim 22, The signal processing step, If the reproducing angle of the reflected sound does not correspond to a multiple of the predetermined angle, identifying the loudspeaker whose angle difference is smaller among the adjacent loudspeakers based on the reproducing angle of the reflected sound with the loudspeaker corresponding to the reproducing angle of the reflected sound. A stereoscopic sound field reproduction method for reflex sound reproduction. The method of claim 23, The signal processing step, Adjusting the angle or the power for the spatial impulse response of the reflection sound in accordance with the identified loudspeaker, stereoscopic sound field reproduction method for the reflection sound reproduction.

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