JP2008011099A - Headphone sound reproducing system and headphone system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce a more ideal sound field, by providing headphones compatible with multichannel reproduction. <P>SOLUTION: To be compatible with 5.1 surround sound, a left sound unit is provided individually with drive units which output a main sound component of LFch, sub-sound components of RFch and Cch, a main sound component of LSch, a sub-sound component of RF, and LFEch. A right sound unit is provided individually with drive units which output the main sound components of RFch, the sub-sound components of Cch and LFch, the main sound component of RSch, the sub-sound component of LF, and LFEch. These drive units are arranged in an array sequence, corresponding to channel sound source positions. Sound signals of the sub-sound components are generated, by applying filter processing and delay processing so that signal characteristic difference with respect to the sound components can be given. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a headphone sound reproduction system provided with a headphone device to perform sound reproduction, and a headphone device provided in such a headphone sound reproduction system.

  For example, it is known that sound reproduction is performed by a so-called multi-channel channel configuration typified by 5.1ch surround. Such a multi-channel audio source is generally output from each speaker arranged in an appropriate positional relationship corresponding to the number of channels, and is reproduced and output in this way. As a result, an audio signal for each channel is generated. When listening to multi-channel sound that is actually played back and output from a speaker, the sound images of various sound sources are localized around the listening position, which is more stereoscopic and realistic than, for example, two-channel stereo. You can enjoy a sound effect with a feeling.

  As described above, the original multi-channel sound reproduction should be performed by arranging as many speakers as the number of channels, but even with headphones reproduction, it is as if the speakers were actually arranged and listened to. A signal processing technique for allowing a sound image to be localized and heard at an appropriate position outside the listener's head has been proposed, and is being realized and popularized.

In such a signal processing technique, for example, a transfer function of a route from when a sound emitted from a sound source corresponding to each channel reaches the listener's left and right ears and can be heard is used. The transfer function used in this case corresponds to, for example, a sound transfer characteristic from the sound source to the eardrum of the listener, and is also referred to as a head-related transfer function.
Then, after assigning audio signals as sound sources for each channel constituting the multi-channel to correspond to the left ear and the right ear, signal characteristics based on the head-related transfer function are given to these audio signals. To be done. That is, from the original sound of the audio signal of each channel, a signal having a characteristic that reaches the left ear from the sound source position as that channel and a signal that has a characteristic that reaches the right ear are generated. Then, a signal obtained by synthesizing a signal having a head-related transfer function of a path to reach the left ear of each channel is reproduced and output as a sound from the left drive unit of the headphone, and similarly reaches the right ear of each channel. The signal obtained by synthesizing the signal having the head-related transfer function of the path up to is reproduced and output as a sound from the right drive unit of the headphone.
The sound that is played back and output in this way, for example, when the listener listens almost directly to both ears with headphones, the sound image is not localized in the head, but for example, a speaker corresponding to multi-channel is actually arranged The sound image localization equivalent to listening in an environment is felt. That is, it is possible to obtain a so-called surround sound effect.

JP 2003-274493 A

However, since the sound reproduction system using headphones as described above obtains a virtual sound field by signal processing using the head-related transfer function, there is no acoustic effect that the user can actually hear. The current situation is that there are not a few things that are felt to be sufficient.
One of the main causes is that the audio signals of the respective channels obtained based on the head-related transfer function are combined as the audio signals of the left and right channels in correspondence with the left and right drive units.
In a multi-channel playback environment where speakers are actually arranged, sounds (sound waves) emitted from the speakers of each channel are synthesized in space. The listener will listen to this synthesized sound. For example, in this case, even if signals that are out of phase are reproduced between different channels, they are not accurately canceled out by being synthesized in space, but this is rather rich sound. It is a factor of getting a sense of place.
On the other hand, in the headphone sound reproduction system, instead of synthesizing sound in space, synthesis is performed at the audio signal stage. Then, if the signals are out of phase between different channels, the signals will cancel each other out, which makes the sound field feel unnatural or inadequate. It will lead to things.
Regarding the above problems, it is the present situation that a particularly effective solution has not been achieved. Therefore, as a headphone sound reproduction system that obtains a virtual sound field corresponding to multichannel, It can be said that there is still room for a faithful sound effect.

In view of the above-described problems, the present invention is configured as a headphone sound reproduction system as follows.
That is, a plurality of drive unit pairs corresponding to the left and right ears are provided for each of a plurality of channels constituting a predetermined channel configuration, and at least one of the drive unit sets is a virtual sound source of the corresponding channel. The main audio signal corresponding to the main audio component that is supposed to reach the position corresponding to one ear from the position is input and reproduced and output so that the reproduced and outputted audio can be heard by one ear. And a sub-audio signal corresponding to a sub-sound component that is supposed to reach the position corresponding to the other ear from the virtual sound source position of the corresponding channel, and the main sound-corresponding one-side drive unit. And a sub-audio compatible one-side drive unit provided so that the reproduced and output sound can be heard by the other ear. , It was decided to include the sub-audio signal characteristic applying means for obtaining a sub-audio signal by providing a signal characteristic corresponding to the difference between the predetermined characteristics of the sub-audio components to the main audio component with respect to the main audio signal.

In the above configuration, a set of a plurality of drive units is provided corresponding to a predetermined channel configuration. A drive unit has a structure including a diaphragm and is driven by a drive signal corresponding to an audio signal, and is a part for outputting sound. The drive unit is composed of a pair (two) of drive units, one for each right ear, and one of the pair of drive units is a main audio-compatible one-side drive unit and has a corresponding channel. The main audio signal corresponding to the main audio component that is supposed to reach the position corresponding to one ear from the virtual sound source position is input and played back, and the other drive unit is a sub-audio compatible one-side drive unit, and the same channel Input a sub audio signal corresponding to a sub audio component that is supposed to reach the position corresponding to the other ear from the virtual sound source position. It is adapted to raw output.
That is, as a basic concept of the configuration according to the present invention, in reproducing the sound source position corresponding to each channel, the sound signal (main sound signal) of the sound component that the sound source of that channel reaches one ear and the other sound source position are reproduced. After generating an audio signal (sub audio signal) of the audio component that reaches the ear, the audio signal is reproduced and output so that it can be heard by the right ear or the left ear by each independent drive unit. It is what.
With such a configuration, for example, the sound that should reach the left and right ears from the sound source position for each channel is emitted from the drive unit and first synthesized in a space close to the ears, Through the eardrum.

  As described above, according to the present invention, the sound that is supposed to arrive at the left and right ears from the sound source position for each channel is reproduced in headphones, and then synthesized in space before being heard in the ear. It is made to reach. Thus, it is possible to provide a headphone sound reproduction system that can reproduce a sound field that is closer to the ideal than before.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below.
In the present embodiment, a sound image localization obtained by a multi-channel configuration represented by, for example, 5.1ch surround is virtually realized as a headphone sound reproduction system. First, the basic configuration concept of a technique for realizing such virtual sound image localization by headphone reproduction will be described.

Here, the simplest example of sound image localization of a sound source is given. In other words, a case is considered where the sound image localization of a single sound source having a certain positional relationship with the listener is virtually reproduced by the headphones. For example, as schematically shown by the acoustic model of FIG. 17, this is understood as a relationship between the listener M and one sound source Src that is assumed to be at a fixed angle and a fixed distance with respect to the listener M. be able to. As shown in this figure, the sound emitted from the sound source Src is transmitted to the left ear of the listener M in such a manner that the transfer function H1 is convoluted and transferred to the right ear. Is given and transmitted.
Here, the transfer functions Hl and Hr are head-related transfer functions corresponding to sound transfer characteristics from the sound source to the eardrum of the listener. Further, since the sound source Src in this case is located on the left side in front of the listener M, among the sounds that reach the left and right ears of the listener M from the sound source Src, the sound that reaches the left ear is The sound that reaches the right ear is a crosstalk component that can be heard by the right ear by diffracting the sound that can be heard by reaching the left ear. Therefore, it can be handled as a sub audio component with respect to the main audio component.

FIG. 18 shows the frequency characteristics A of the sound by the path of the transfer function H1 and the right ear of the listener M, which are assumed to be emitted from the sound source Src and heard by the listener M's left ear in FIG. The frequency characteristic B of the sound according to the path of the transfer function Hr, which is assumed to be listened to.
As described above, the sound source Src in this case is located at the left front of the listener M, so that the sound heard by the listener M's left ear is directly sound. On the other hand, the sound heard by the listener M's left ear is an indirect sound and a crosstalk component. As the difference between the frequency characteristic B and the frequency characteristic A, the sound pressure of the frequency characteristic B is smaller corresponding to this.

In this way, the sound emitted from one sound source Src and reaching the left and right ears has a different frequency characteristic. Further, as shown in FIG. 17, there is a distance difference Ds between the distance from the sound source Src to the left ear and the distance to the right ear, and the sound source Src emits according to the distance difference Ds. An arrival time difference dl, which is a time difference in which the received sound reaches the left and right ears, is also generated. The transfer functions Hl and Hr shown in FIG. 17 give such characteristic differences as frequency characteristic difference and arrival time difference to the original sound that is supposed to be emitted from the sound source Src.
The sound image localization ability of a person is based on a difference in predetermined characteristics such as a frequency characteristic difference (including a volume difference element in this case) and a time difference between sounds to be heard between the left ear and the right ear as described above. It is said to perceive the sense of localization of the sound image. Based on this, in order to reproduce the virtual sound image localization of one sound source with headphones, the above-described signal characteristic difference corresponding to the main sound component and the sub sound component is given based on the sound signal of the original sound. Two audio signals are obtained, one of these audio signals is reproduced and output from the drive unit corresponding to the left ear, and the other is reproduced and output from the drive unit corresponding to the right ear.

Based on the above, as shown in the acoustic model of FIG. 19, the sound image localization assumed to be obtained by the left sound source Srcl and the right sound source Scrr arranged on the left and right front with respect to the listener M is reproduced with headphones. Consider the case.
In this case, first, the sound emitted from the left sound source Srcl reaches the left ear of the listener M to which the transfer function Hll is given as the main voice, and reaches the right ear with the transfer function Hlr given as the auxiliary voice. It is supposed to be. In addition, the sound emitted from the right sound source Scrc reaches the right ear of the listener M given the transfer function Hrr as the main voice component, and is given to the left ear of the listener M given the transfer function Hrl as the secondary voice. It is supposed to reach.

The configuration shown in FIG. 20 can be considered as the configuration of the signal processing system for realizing the sound image localization by the left and right front shown in FIG.
First, in the configuration shown in FIG. 20, the input signal corresponds to the original sound signal S1 corresponding to the original sound emitted from the left sound source Srcl in FIG. 19 and the original sound emitted as the right sound source Scrc in FIG. The original audio signal Sr is input.
The original audio signal Sl is branched into a system that is directly input to the synthesizer 13a and a system that is input from the filter 11b to the synthesizer 13b via the delay unit 12b. The original audio signal Sr is also branched into a system that is directly input to the synthesizer 13b and a system that is input from the filter 11a to the synthesizer 13a via the delay device 12a.

In the synthesizer 13a, as described above, the directly input original audio signal S1 and the signal obtained by processing the original audio signal Sr by the filter 11a and the delay device 12a are synthesized, and the left (L) output channel is synthesized. As a signal for use, the drive unit SPu-L corresponding to the left ear is output as sound.
Further, the synthesizer 13b synthesizes the directly input original audio signal Sr and the signal obtained by processing the original audio signal S1 with the filter 11b and the delay unit 12b to obtain a right (R) output channel signal. The drive unit SPu-R corresponding to the right ear is output as sound.
In actuality, these drive units are, for example, parts that include a diaphragm made of a predetermined material shape and reproduce sound by driving the diaphragm with a drive current obtained by amplifying an audio signal. . In other words, the speaker unit is configured to reproduce sound near the ear, such as headphones.

In the configuration shown in FIG. 20, first, the system in which the original audio signal S1 is directly input to the synthesizer 13a and reaches the drive unit SPu-L corresponds to the main audio component reaching the left ear from the left sound source Srcl. This is equivalent to giving a signal characteristic corresponding to the transfer function Hll as described later. On the other hand, the system in which the original audio signal S1 reaches the drive unit SPu-R via the filter 11b, the delay unit 12b, and the synthesizer 13b corresponds to the sub audio component that reaches the right ear from the left sound source Srcl. Then, a signal characteristic difference (frequency characteristic difference, arrival time difference dl) with respect to the main audio component is given by the filter 11b and the delay unit 12b, so that a signal characteristic equivalent to the convolution of the transfer function Hlr is given. .
Similarly, a system in which the original audio signal Sr is directly input to the synthesizer 13b and reaches the drive unit SPu-R corresponds to the main audio component that reaches the right ear from the right sound source Scrc and corresponds to the transfer function Hrr. The system in which the original audio signal Sr reaches the drive unit SPu-L via the filter 11a, the delay unit 12a, and the synthesizer 13a is assumed to give signal characteristics, and the sub audio component that reaches the left ear from the right sound source Src. By providing a characteristic difference with respect to the main audio component by the filter 11a and the delay device 12a, a signal characteristic equivalent to the convolution of the transfer function Hlr is given.

For example, as a general thing about two-channel stereo headphones by L and R, the characteristics of the sound reproduced by the acoustic unit including the frequency characteristics of the reproduced sound of the drive unit are actually set by the listener wearing the headphones. When listening to the sound reproduced from the acoustic units of the left and right ears, the frequency band balance is set so that it can be heard naturally. From this, at the stage of sound reproduction by the headphone device, for example, the reproduction function of each channel of L and R corresponds to each channel, and the transfer function corresponding to the path to reach the left and right ears. Can be considered as approximately given. As a headphone device corresponding to the present embodiment, for example, a drive unit or the like is formed on the premise of this.
Based on the above, at least a system in which the signal S1, which is the main audio component in FIG. 20, is directly input to the combiner 13a and reaches the drive unit SPu-L, and the signal Sr is directly input to the combiner 13b. The system that is input and reaches the drive unit SPu-R is equivalent to the fact that the transfer functions Hll and Hlr are convoluted by outputting the sound as a sound from the drive unit without performing filtering or delay processing. In other words, it can be understood that a sound with a characteristic can be obtained.
In addition, as described above, with respect to the sub audio component corresponding to the main audio component, a frequency characteristic difference and arrival time difference with respect to the main audio component corresponding to the transfer function are given by the filter and the delay unit. To be done.
As a result, the main sound by the transfer function Hll that should reach the left ear from the left sound source Srcl and the sub-voice by the transfer function Hlr that should reach the right ear are reproduced and output from the drive units SPu-L and SPu-R, respectively. Therefore, if this sound component is heard, it can be perceived that the left sound source Srcl is localized at an appropriate position. Similarly, the main sound by the transfer function Hrr that should reach the right ear from the right sound source Scrc and the auxiliary sound by the transfer function Hrl that should reach the left ear are reproduced and output from the drive units SPu-R and SPu-L, respectively. Therefore, when listening to this sound component, it can be perceived that the right sound source Scrc is localized at an appropriate position. In other words, the listener can perceive a sound image in which the left sound source Srcl and the right sound source Scrr are localized at appropriate positions in the left and right front, and virtual sound image localization is realized.

  Here, the relationship between the headphone device corresponding to the system configuration shown in FIG. 20 and the listener's head is shown in FIG. The headphone device in this case has a left acoustic unit 1L and a right acoustic unit 1R corresponding to each of the left and right ears of the listener M as shown in FIG. Although not shown here, for example, the left acoustic unit 1L and the right acoustic unit 1R are connected by a headband or the like, and a structure that can be mounted on the head is adopted. The left acoustic unit 1L and the left acoustic unit 1R are respectively attached with drive units SPu-L and SPu-R. When the headphone device is properly mounted on the head, the drive units SPu-L and SPu are mounted. -R is positioned at the optimum positions that can be heard by the left and right ears, respectively.

  Next, the configuration of the headphone sound reproduction system corresponding to a more practical multi-channel configuration based on the configuration corresponding to the two sound sources (two-channel configuration) described with reference to FIGS. 19 to 21 will be described with reference to FIGS. Will be described with reference to FIG. Here, a case where the multi-channel configuration is adapted to the 5.1ch surround standard is taken as an example.

First, FIG. 22 schematically shows a model of a 5.1 channel surround channel configuration.
As is well known, 5.1ch surround is also referred to as a subwoofer such as LF (Left Front) ch, C (Center) ch, RF (Right Front) ch, LS (Left Surround) ch, and RS (Right Surround) ch. A channel configuration with a total of 6 channels of LFE (Low Frequency Effect) ch is assumed. For these channels, for example, an ideal sound source position by ITU-R, for example, the position and height of the speaker with respect to the listening position (listener M) are defined. However, for LFEch, the reproduction frequency band is considerably low relative to other channels, so the directivity is low, and it is difficult for listeners to feel a clear localization, so the definition of the sound source position is loose. It is said that.

In FIG. 22, speakers SP-LF, SP-C, SP-RF, SP-LS, SP-RS, SP-LFE are used as sound sources corresponding to LFch, Cch, RFch, LSch, RSch, and LFEch. A model is shown in which the listener M listens to the sound output from these speakers and reaching the left and right ears respectively.
For example, as the positions of these speakers in accordance with the 5.1ch surround standard, the speaker SP-LF is disposed at the front left relative to the position of the listener M, the speaker SP-C is disposed at the center front, and the speaker is disposed at the right front. The SP-RF is arranged, the speaker SP-LS is arranged on the left rear side, and the speaker SP-RS is arranged on the right rear side.

Then, according to FIG. 19, the following transfer function (head-related transfer function) is used for the sound path from each speaker to the right and left ears of the listener M under the channel configuration shown in FIG. ).
Hfl: Transfer function of the path reaching the left ear as the main audio component from the speaker SP-LF Hlfr: Transfer function of the path reaching the right ear as the sub audio component from the speaker SP-LF Hcl: Main audio / from the speaker SP-C Transfer function of a path reaching the left ear as a sub audio component Hcr: Transfer function of a path reaching from the speaker SP-C to the right ear as a sub audio / main audio component Hrfl: From the speaker SP-RF to the left ear as a sub audio component Transfer function of the path to reach Hrfr: Transfer function of the path reaching the right ear as the main audio component from the speaker SP-RF Hlsl: Transfer function of the path reaching the left ear as the main audio component from the speaker SP-LS Hlsr: Speaker SP -Transfer function Hrsl of the path reaching the right ear from the LS as a sub audio component Hrsl: Transfer function H of the path reaching the left ear as a sub sound component from the speaker SP-RS rsr: transfer function of the path from the speaker SP-RS to the right ear as the main audio component

FIG. 23 shows an example of a headphone playback system that is based on the basic concept shown in FIGS. 19 and 20 and that supports 5.1 ch surround.
First, also in this figure, as a drive unit, a pair of drive units SPu-L and SPu-R corresponding to the left output channel and the right output channel are provided. The drive unit SPu-L receives the left output channel audio signal obtained by synthesizing the input audio signal by the synthesizer 13a, and the drive unit SPu-R obtains the input audio signal by the synthesizer 13b. The received right output channel audio signal is input.

In addition, the audio signal of each channel as 5.1ch surround is distributed and input to the combiners 13a and 13b as follows.
First, the LFch original audio signal is directly input to the synthesizer 13a, and is input to the synthesizer 13b via the filter 11b and the delay value 12b.
The RFch original audio signal is directly input to the synthesizer 13b and is input to the synthesizer 13a via the filter 11a and the delay unit 12b.
The Cch original audio signal passes through the filter 11e and the delay device 12e and is branched into two systems, and the signals of each system are input to the synthesizer 13a and the delay device 13b, respectively.
The original LSch audio signal is input to the synthesizer 13a via the filter 11d and the delay unit 12d, and is input to the synthesizer 13b via the filter 11g and the delay unit 12g.
The RSch original audio signal is input to the synthesizer 13a via the filter 11c and the delay unit 12c, and is input to the synthesizer 13b via the filter 11f and the delay unit 12f. z
First, the LFEch original audio signal is branched into two systems, and the signals of each system are directly input to the synthesizer 13a and the synthesizer 13b, respectively.

In the configuration shown in FIG. 23, first, the configuration of the signal system corresponding to the combination of LFch and RFch is the basics of the headphone system corresponding to the two channels of the left sound source Srcl and the right sound source Scrc shown in FIG. Corresponds to the configuration. For this reason, the signal corresponding to the main audio component (left output channel) of LFch is output from the synthesizer 13a by the drive unit SPu-L without passing through a filter and a delay unit. It is trying to obtain a sound with the same signal characteristics as the convolution. The signal corresponding to the LFch sub-sound component (right output channel) is passed through the filter 11b and the delay unit 12b, thereby giving the sub-sound frequency characteristic difference and arrival time difference with respect to the main sound. The sound having the same signal characteristic as that obtained by convolution of the transfer function Hlfr is obtained.
Similarly, the signal corresponding to the main audio component (right output channel) of RFch is output from the synthesizer 13b by the drive unit SPu-R without passing through the filter and delay device, so that the transfer function Hrfl is convoluted. For the signal corresponding to the RFch sub-sound component (left output channel), the signal corresponding to the RF channel sub-sound component (left output channel) is passed through the filter 11a and the delay unit 12a, so A frequency characteristic difference and arrival time difference are given, and a sound having a signal characteristic equivalent to the convolution of the transfer function Hrfl is obtained.

Further, the filter 11d and the delay device 12d provided corresponding to the main audio component (left output channel) of the LSch, in order to obtain a signal characteristic equivalent to the convolution of the corresponding transfer function Hlsl, Parameters (passband characteristics, delay time) for giving characteristic differences (frequency characteristic differences and arrival time differences) with respect to voice components are set. In other words, if the main audio component of LSch is used as a reference, the main audio component of LFch has a different path to reach the left ear depending on the position of each sound source. This characteristic difference is obtained by the filter 11d and the delay device 12d.
In addition, the filter 11g and the delay device 11g provided corresponding to the LSch sub-sound component (right output channel) have the same LSch in order to obtain a signal characteristic equivalent to the convolution of the corresponding transfer function Hlsr. A parameter for giving a characteristic difference with respect to the main audio component is set.

  Further, the filter 11f and the delay device 11f provided corresponding to the main audio component (right output channel) of the RSch have a main characteristic of the LFch in order to obtain a signal characteristic equivalent to the convolution of the corresponding transfer function Hlsl. A parameter for giving a characteristic difference with respect to the sound component is set. In addition, the filter 11g and the delay device 11g provided corresponding to the LSch sub-sound component (right output channel) have the same LSch in order to obtain a signal characteristic equivalent to the convolution of the corresponding transfer function Hrsr. A parameter for giving a characteristic difference with respect to the main audio component is set.

Further, Cch is branched to a signal system corresponding to the left output channel and the right output channel after passing through the filter 11e and the delay device 12e. Cch is a sound source located in front of the listener M as shown in FIG. For this reason, ideally, the transfer characteristics Hcl and Hcr corresponding to the sounds of the respective systems reaching the left and right ears of the listener M are equivalent, and the main sounds such as LFch, RFch, LSch, and RSch There is no difference between the component and the sub audio component. In other words, in Cch, there is a substantial difference between the system corresponding to the left ear of the listener M and the system corresponding to the right ear, whichever is treated as the main audio component or the sub audio component. There is nothing.
However, if the main audio components of LFch and RFch are used as a reference, there is a difference in signal characteristic between sound components corresponding to the left and right ears of Cch. Therefore, if this signal characteristic difference is given, transfer characteristics Hcl and Hcr as Cch are obtained, and the sound image localization is realized. The parameters of the filter 11e and the delay device 12e are set so as to give this signal characteristic difference.

Also, as described above with reference to FIG. 22, the LFEch has a low directivity compared to the sound of other channels because of its low reproduction frequency band. This also applies to headphone playback. Therefore, LFEch is directly branched and input to the combiners 13a and 13b without giving any signal characteristics.
In this way, in the configuration shown in FIG. 23, the transmission characteristics corresponding to the sound component reaching the left ear and the transmission characteristics of the sound component reaching the right ear are convoluted with respect to the audio signals of channels other than LFEch. The left output channel drive unit SPu-L and the right output channel drive unit SPu-R, respectively. Then, when the listener M listens to the sound output in this way, sound image localization corresponding to the sound source position shown in FIG. 22 is perceived.

By the way, as described above, depending on the headphone playback system having the configuration shown in FIG. 23, in principle, it is possible to listen to the virtual sound image localization corresponding to the 5.1ch surround channel configuration. In reality, it has been found that the sound image localization may not be perceived well because it is dilute or unnatural.
One of the main causes is that the audio components for each channel that should reach the left and right ears are electrically synthesized at the audio signal stage using the combiners 13a and 13b. It is done.

The original sound reproduction system as 5.1ch surround is configured to arrange speakers for each channel according to, for example, FIG. 22 and reproduce and output the corresponding channel sound from these speakers. In this case, the left and right ears of the listener M are transmitted to the eardrum after the sound components emitted from the speakers of the respective channels to be reached are synthesized in space.
For example, audio reproduced between channels can be in a state of being out of phase and in phase with each other. In principle, opposite-phase sounds cancel each other out and cannot be heard, and in-phase sounds strengthen each other, but when synthesized in space, they are canceled or strengthened accurately due to the surrounding environment. It is considered that this phenomenon is rather connected to a rich sense of sound field. However, when such phase-related sounds are electrically synthesized at the stage of the audio signal, they will cancel or intensify each other almost accurately, and this may be an unnatural sound. For example, the sound field may be perceived as not good.

Further, another main cause of the poor sense of sound image localization is that individual differences among actual listeners may greatly affect.
The transfer function used in the headphone reproduction system described so far with reference to FIGS. 17 to 23 is called a head-related transfer function, and represents, for example, a transfer characteristic of a sound path from a sound source to the listener's eardrum. It is supposed to be. For this reason, the head-related transfer function includes a characteristic component that is reflected by the human pinna and reaches the eardrum. Actually, there are individual differences in the shape of the human pinna, and it is difficult to set the head-related transfer function corresponding to such differences. Therefore, in setting the head-related transfer function, the pinna shape set as a standard is assumed by an appropriate method. However, the proportion of the characteristics given by the pinna shape in the head-related transfer function is reasonably high. In addition, the actual human pinna shape may differ from person to person, and the individual differences are correspondingly large. For this reason, for example, a listener who has a pinna shape that is quite different from the pinna shape set as a standard will hear a sound far from the sound due to the set transfer function. Sound image localization is perceived.

  In view of this, the present embodiment provides a headphone playback system configured to eliminate the above-described factors as much as possible and obtain a good virtual sound image localization feeling. Hereinafter, the configuration for this purpose will be described.

First, FIG. 1 shows a basic acoustic model which is a prerequisite for the headphone playback system according to the present embodiment. This figure shows a case where the left sound source Srcl and the right sound source Scrr are set at symmetrical positions in front of the listener M (listening position), as in the case of FIG.
For example, in the acoustic model shown in FIG. 19, the transfer functions Hll, Hlr, Hrr, and Hrl of the sound reaching the left and right ears from the left sound source Srcl and the right sound source Scrr correspond to the sound path from the sound source position to the eardrum. Therefore, the measurement point is assumed to be in the auricle corresponding to the eardrum.
On the other hand, in the present embodiment, the measurement points of the sound reaching the left and right ears from the left sound source Srcl and the right sound source Scrr are shown as spatial measurement ranges P1 and P2 and near the outside of the left and right pinna. The position range in the space is set. In the space measurement ranges P1 and P2, measurement positions corresponding to the respective sound sources are set as shown in FIG. First, in the space measurement range P1, the measurement point Pll of the sound that the left sound source Srcl reaches the left ear and the measurement point Prl of the sound that the right sound source Srcr reaches the left ear are set. In the space measurement range P2, a measurement point Prr for the sound that the right sound source Scrc reaches the right ear and a measurement point Plr for the sound that the left sound source Srcl reaches the left ear are set. Note that the position of the measurement points in the horizontal direction (horizontal arrangement direction), the vertical direction (height direction), the distance from the auricle, and the like is set as described later with reference to FIG. In the case of configuring, it is determined corresponding to the arrangement position of the drive unit for reproducing and outputting each of the four sounds. That is, these measurement points (Pll, Prl, Prr, Plr) are assumed to be positions on a space where the corresponding sound drive units are arranged. By setting the measurement points in this way, in the present embodiment, the transfer function of the sound reaching the left and right ears from the left sound source Srcl and the right sound source Scrc is up to just before reaching the pinna. It is assumed that it corresponds to the spatial path, and the effect of the pinna is eliminated.
In FIG. 19, the main sound component and the sub sound component that reach the left and right ears from the left sound source Srcl, and the main sound component and the sub sound component that reach the right and left ears from the right sound source Scrc, Although expressed as Hll, Hlr, Hrr, and Hrl, respectively, the transfer function from which the influence of the pinna handled in this embodiment is excluded as shown in FIG. 1 is expressed as sHll, sHlr, sHrr, and sHrl. I will decide.

Next, FIG. 3 shows a basic configuration corresponding to the acoustic model of FIG. 1 as a configuration example of the audio signal processing system of the headphone acoustic reproduction system of the present embodiment.
In the configuration of FIG. 3, as input signals, the original sound signal Sl corresponding to the original sound emitted from the left sound source Srcl in FIG. 1 and the original sound signal corresponding to the original sound emitted as the right sound source Scrc in FIG. Sr is input.
In addition, the original audio signal S1 is branched into two systems corresponding to the main audio component reaching the left ear from the left sound source Srcl and the sub audio component reaching the right ear, and the system corresponding to the main audio component is By performing reproduction and output by the drive unit SPu-L without particularly performing filter processing and delay processing, it is possible to obtain sound equivalent to that in which the transfer function sHll is convoluted. Here, with respect to the system corresponding to the main audio component, the signal characteristic equivalent to the convolution of the transfer function sHll is given by not performing the filter process and the delay process in particular. This is because the audio signal of the system corresponding to the main audio component in is not subjected to filter processing and delay processing. The same applies to a system that outputs the original audio signal Sr from the drive unit SPu-R corresponding to the main audio component of the right sound source Scrc, which will be described later.
The system corresponding to the sub audio component from the left sound source Srcl is reproduced and output by the drive unit SPu-f (L) after passing through the filter 11-f (L) and the delay device 12-f (L). Like that. In the present embodiment, although a transfer function in which the influence of the pinna is eliminated is given, the signal characteristics of the sound measured at an appropriate measurement point reaching the left ear side from one sound source, and the right ear side However, there is still a difference in frequency characteristics and time of arrival due to differences in the sound arrival angle and direction, and the difference in transfer characteristics. It is also expressed as Therefore, depending on the filter 11-f (L) and the delay unit 12-f (L), the transfer function sHrl is convoluted by giving a signal characteristic difference with respect to the main sound component from the left sound source Srcl. The signal characteristic equivalent to is obtained.

The original audio signal Sr is also branched into two systems corresponding to the main audio component reaching the right ear from the right sound source Scrc and the sub audio component reaching the left ear, and the system corresponding to the main audio component is Without performing filter processing and delay processing in particular, reproduction and output are performed by the drive unit SPu-R, and sound equivalent to that in which the transfer function sHrr is convoluted is obtained.
Further, the system corresponding to the sub sound component from the right sound source Scrc passes through the filter 11-f (R) and the delay device 12-f (R), and the signal characteristic difference with respect to the main sound component from the right sound source Scrc is obtained. And reproduced and output by the drive unit SPu-f (R). As a result, a sound having a signal characteristic equivalent to the convolution of the transfer function sHlrl is reproduced.

For example, in the configuration of the headphone playback system according to FIG. 20 described above, there is only one drive unit for each of the left and right output channels, and it corresponds to the sound that reaches the left ear from two sound sources and can be heard. And the audio signal corresponding to the sound that can be heard by reaching the right ear are combined and then output by the drive units SPu-L and SPu-R of the left and right output channels. .
On the other hand, in the present embodiment, the left and right output channels (L, R) are used to output audio signals corresponding to sounds that are supposed to reach the left ear side and the right ear side from the left sound source Srcl and the right sound source Scrc. Rather than combining them individually, they are output from independent drive units. In other words, in the present embodiment, the output channel, that is, the drive unit SPu− corresponds to each audio signal corresponding to the sound that is supposed to reach the left ear side and the right ear side from the respective sound sources of the left sound source Srcl and the right sound source Scrc. L is provided. Here, output channels L, R, f (R), and f (L) are shown corresponding to the drive units SPu-L, SPu-R, SPu-f (R), and SPu-f (L). ing.

FIG. 4 schematically shows an arrangement structure example of the drive units in the left and right acoustic units as an example of the headphone device corresponding to the configuration of the audio signal system shown in FIG.
As shown in this figure, first, the left acoustic unit 1L of the headphone device is provided with drive units SPu-L and SPu-f (R), and the sound reproduced by these drive units by the left ear. Can be heard. In the right acoustic unit 1R, drive units SPu-R and SPu-f (L) are provided so that sounds reproduced by these drive units can be heard by the right ear.
In addition, as an arrangement of the drive unit in the left acoustic unit 1L, first, the drive unit SPu-L is arranged in correspondence with the position corresponding to the measurement point Pll in FIG. For example, this position is regarded as a reference position that is not biased forward or backward with respect to the ear. The drive unit SPu-f (R) is arranged in front of the drive unit SPu-L, for example, at a position corresponding to the measurement point Prl separated by a predetermined distance difference DS1.
As for the arrangement of the drive unit in the right acoustic unit 1R, the drive unit SPu-R is arranged corresponding to the reference position corresponding to the measurement point Prr in FIG. 1 in accordance with the left acoustic unit 1L. The drive unit SPu-f (L) is arranged at a position corresponding to the measurement point Plr that is separated from the drive unit SPu-R by a distance difference DS1.

In the basic configuration of the headphone playback system according to the present embodiment shown in FIG. 3 and FIG. 4, first, for the left sound source Srcl, the main audio component output from the drive unit SPu-L is heard with the left ear, The sub-audio component output from the drive unit SPu-f (L) is heard with the right ear. At this time, since the drive unit SPu-f (L) is located in front of the drive unit SPu-R that is arranged on the basis of the right ear, the sound of this sub-sound component is made to come from the front. Will reach the ear. Thereby, the listener can perceive the sound of the left sound source Srcl as being localized left front.
Similarly, for the right sound source Scrc, the main audio component output from the drive unit SPu-R is heard with the right ear, and the sub audio component output from the drive unit SPu-f (R) with the left ear. It is made to listen. Since the drive unit SPu-f (R) is also located in front of the drive unit SPu-L that is arranged on the left ear side as a standard, the sound of this sub-sound component reaches the ear so that it also comes from the front. In other words, the sound of the right sound source Sccr can also be perceived as being localized left front. That is, it is possible to perceive the sound image localization of the left sound source Srcl and the right sound source Srcr.

On the left ear of the listener M, the main sound component from the left sound source Srcl corresponding to the output channel L and the sub sound component from the right sound source Scrc corresponding to the output channel f (R) are left acoustic unit. It will be heard after being synthesized in the space in 1L. Similarly, in the right ear of the listener M, the main sound component from the right sound source Scrr corresponding to the output channel R and the sub sound component from the left sound source Srcl corresponding to the output channel f (L) are After being synthesized in the space in the acoustic unit 1R, it will arrive and be heard.
In this way, in the headphone device of the present embodiment, the sound of the output channel that is supposed to reach each ear from the sound source is reproduced by each independent drive unit and then synthesized in a space close to the left and right ears. ing. For this reason, for example, when the audio signal corresponding to the sound that is supposed to reach each ear from the sound source is electrically synthesized and then output as a sound, the opposite-phase and in-phase signals cancel each other exactly. Or the phenomenon of strengthening each other. This makes it possible to obtain a better sound field feeling.

Further, as in the present embodiment, the sound for each output channel that is supposed to reach each ear from the sound source is synthesized in space and then reaches the ear. It can be said that the emitted sound reaches the eardrum after being synthesized in space and then reflected by the auricle.
Therefore, as in the present embodiment, transfer characteristics (frequency characteristics, delay time difference) excluding the influence of the pinna are applied to the audio signal for each output channel that is supposed to reach each ear from the sound source. For example, the characteristics that change corresponding to the pinna can be formed by the pinna of the actual listener. This means that it is possible to feel a good sound image localization regardless of individual differences such as the shape of the pinna.
In this way, the headphone playback system according to the present embodiment is configured so that more people can obtain a sound image localization feeling that is better than before.

By the way, the delay times of the delay units 12-f (R) and 12-f (L) shown in FIG. 3 are the same as those described so far. An arrival time difference determined according to the distance until the component reaches and the distance until the sub audio component reaches the other ear is given to the audio signal of the sub audio component. For example, in the case of the configuration shown in FIG. 20, the sound of the main sound component of one sound source and the sound of the sub sound component of the other sound source are synthesized at the stage of the sound signal. The best mode is to give the time difference as it is.
However, in the present embodiment, as shown in FIG. 4, for example, in the case of the left acoustic unit 1L, the physical distance DS1 is given for the arrangement positions of the drive unit SPu-L and the drive unit SPu-f (R). Therefore, it is inevitably output from the drive unit SPu-f (R) with respect to the time that the main sound of the left sound source Srcl output from the drive unit SPu-L reaches the left ear according to the distance DS1. A delay in the time for the sub sound of the right sound source Sccr to reach the left ear will occur. Therefore, in order to obtain the arrival time difference in the best mode, depending on the distance from the left sound source Srcl until the main audio component reaches the left ear and the distance until the sub audio component reaches the right ear The time obtained by subtracting the delay time corresponding to the distance DS1 from the determined arrival time difference should be set in the delay device 12-f (R).

  Subsequently, a configuration example of a headphone sound reproduction system corresponding to multi-channel based on the basic configuration described with reference to FIGS. 1 to 4 will be described. In this case as well, the multi-channel configuration is taken as an example in the 5.1ch surround standard.

First, FIG. 5 shows a 5.1 ch surround acoustic model corresponding to the present embodiment.
Also in the acoustic model shown in this figure, speakers SP-LF, SP-C, SP- are used as sound sources corresponding to LFch, Cch, RFch, LSch, RSch, and LFEch, for example, as shown in FIG. RF, SP-LS, SP-RS, and SP-LFE are shown. Also, the arrangement of these speakers is the same as in FIG.
However, in this embodiment, when configuring a headphone sound reproduction system that supports 5.1ch surround, transmission of each sound that is supposed to reach the left and right ears of the listener M from the sound source (speaker) of each channel. As described above with reference to FIG. 1, the function is a function excluding the influence of the pinna. In other words, in the vicinity of the outside of the left and right pinna, the measurement is performed at the measurement points set in the space measurement ranges P1 and P2, which is a set range of measurement points in the space where the drive unit corresponding to each sound is located. The transfer function of sound from each sound source is used.
An example of setting measurement points in the space measurement ranges P1 and P2 in this case is shown in FIG. First, in the space measurement range P1 corresponding to the left ear, the measurement point Pcl of the sound arriving from the SP-C is set in front of the measurement point Plfl corresponding to the sound arriving from the speaker SP-LF. Further ahead, the measurement point Prfl of the sound reaching from the speaker SP-RF is set. In addition, a measurement point Plsl of sound arriving from the speaker SP-LS is set behind the reference measurement point Plfl, and a measurement point Prsl of sound arriving from the speaker SP-RS is set further behind. is doing.
In the space measurement range P2 corresponding to the right ear, the measurement point Pcr of the sound arriving from the SP-C is set in front of the measurement point Prfr corresponding to the sound arriving from the speaker SP-RF. Further ahead, a measurement point Plfr for a sound reaching from the speaker SP-LF is set. In addition, a measurement point Prsr of sound arriving from the speaker SP-RS is set behind the reference measurement point Prfr, and a measurement point Plsr of sound arriving from the speaker SP-RS is set further behind. is doing.
Here, as shown in FIG. 5, the transfer function corresponding to each sound is expressed as follows.
sHlfl: Transfer function of the path from the speaker SP-LF to the left ear side (measurement point Plfl) as the main audio component
sHlfr: Transfer function of the path from the speaker SP-LF to the right ear side (measurement point Plfr) as a sub audio component
sHcl: transfer function of the path from the speaker SP-C to the left ear side (measurement point Pcl) as the main sound / sub sound component
sHcr: transfer function of a path from the speaker SP-C to the right ear side (measurement point Pcr) as a sub-sound / main sound component
sHrfl: Transfer function of the path from the speaker SP-RF to the left ear side (measurement point Prfl) as a secondary audio component
sHrfr: transfer function of the path from the speaker SP-RF to the right ear side (measurement point Prfr) as the main audio component
sHlsl: transfer function of the path from the speaker SP-LS to the left ear side (measurement point Plsl) as the main audio component
sHlsr: transfer function of the path from the speaker SP-LS to the right ear side (measurement point Plsr) as a secondary audio component
sHrsl: transfer function of the path from the speaker SP-RS to the left ear side (measurement point Prsl) as a sub audio component
sHrsr: transfer function of the path from the speaker SP-RS to the right ear side (measurement point Prsr) as the main audio component

Next, a configuration example of a signal system corresponding to 5.1ch surround will be described with reference to FIG. 7 as the headphone sound reproduction system of the present embodiment.
In the description here, the description will be made on the assumption that the signal processing system is simplified by omitting the filter 11 and the delay unit 12 shown in FIG.

First, in this configuration, for each of the six channels (LFch, Cch, RFch, LSch, RSch, LFEch) constituting 5.1ch surround, 12 outputs corresponding to the sound components reaching the left ear and the right ear respectively. Channel (LF, f (LF), RF, f (RF), C (L), C (R) LS, f (LS), RS, f (RS), LFE (L), LFE (R)) It is supposed to be provided. In addition, the drive units also correspond to each of these output channels, and drive units SPu-LF, SPu-f (LF), SPu-RF, SPu-f (RF), SPu-C (L), SPu-C ( R), SPu-LS, SPu-f (LS), SPu-RS, SPu-f (RS), SPu-LFE (L), SPu-LFE (R) are provided.
In addition, a signal system for each audio signal of each channel as 5.1ch surround is formed as follows. In addition, since description here presupposes the above-mentioned simple structure, the filter 11 and the delay device 12 which are shown with a broken line are handled as what is abbreviate | omitted.

  First, in the configuration of the signal system shown in FIG. 7, the basic configuration corresponding to FIG. 3 is provided as a signal system corresponding to LFch and RFch. That is, as the correspondence relationship between the channels in FIGS. 3 and 7, on the input source side, the left sound source Srcl and the right sound source Scrr in FIG. 3 correspond to LFch and RFch in FIG. 3, L, f (L), R, and f (R) correspond to LF, f (LF), RF, and f (RF), respectively.

In accordance with the above-described correspondence, first, the original LFch audio signal is branched into two systems, and one system is directly subjected to the drive unit SPu− without being subjected to filter processing and delay processing as main audio components. It is input to the LF. It is assumed that the transfer function sHlfl is given by this system. Further, the other system passes through the filter 11-f (LF) and the delay unit 12-f (LF), so that a signal characteristic of the difference with respect to the main audio component is given, and the drive unit SPu-f (LF ), So that the given sound is reproduced such that the transfer function sHlfr is convoluted.
In addition, the original audio signal of RFch, which is the sound source that is the left and right target for LFch, is also branched into two systems of a main audio component and a sub audio component, and the main audio component system is subjected to filter processing and delay processing. Instead, the transfer function sHrfr is given so as to be input directly to the drive unit SPu-RF. Further, the sub audio component system passes through the filter 11-f (RF) and the delay device 12-f (RF), so that the signal characteristic of the difference with respect to the main audio component is given, and the drive unit SPu-f (LF) is input, so that the sound given the transfer function sHrfl is reproduced.
Then, the remaining LSch, RSch, Cch, and LFEch signal systems are provided for the basic components as described below.

The original audio signal of Lsch is directly input to the drive unit SPu-LS without passing through the filter processing or the like for the main audio component, thereby reproducing the audio given the transfer function sHlsl. . Further, with respect to the sub audio component, the transfer function sHlsr is given by being input to the drive unit SPu-f (LS) via the filter 11-f (LS) in order to give a signal characteristic difference with respect to the main audio component. Get playback audio.
In addition, the Rsch original audio signal that is symmetrical with respect to the LSch is directly input to the drive unit SPu-RS without passing through the filter processing or the like for the main audio component, thereby giving the transfer function sHrsr. To play the recorded audio. Further, the sub-sound component is given a transfer function sHrsl by being input to the drive unit SPu-f (RS) via the filter 11-f (RS) in order to give a signal characteristic difference with respect to the main sound component. Get playback audio.

  In addition, the Cch original audio signal is also split into two, so that one system is directly input to the drive unit SPu-C (L) and the other system is directly input to the drive unit SPu-C (R). I try to let them. As described above with reference to FIG. 23, since Cch is a sound source that is localized in front of the listener M, it is located at positions (measurement points P1, P2) corresponding to the left and right ears of the listener M. Therefore, it is assumed that there is no difference in signal characteristics corresponding to the main audio component and the sub audio component, and the transfer functions sHcl and sHcr of each sound are equivalent. For this reason, as described above, the same Cch original sound signal is input to the drive units SPu-C (R) and SPu-C (L) corresponding to the left and right acoustic units.

  Further, as described with reference to FIG. 23, the directivity of the LFEch sound is dull. Therefore, assuming that the same sound is output from the left and right acoustic units, it is sufficient to divide the LFEch original audio signal into two systems, and the signals of each system are The drive units SPu-LFE (L) and SPu-LFE (R) corresponding to the sound units are directly input.

  Here, the sound reproduction characteristics of the twelve drive units shown in FIG. 7 are the same. If it is assumed that the acoustic unit reproduction characteristics are equivalent, it becomes easy to set the passband characteristics of the filter 11. However, the drive units SPu-LFE (L) and SPu-LFE (R) corresponding to LFEch are required to reproduce a considerably lower band compared to the frequency band to be reproduced by other drive units. The sound reproduction characteristics may be suitable for such low-frequency reproduction.

Next, an arrangement example of the drive unit in the headphone device corresponding to the configuration of the signal system shown in FIG. 7 will be described with reference to FIGS.
First, as shown in FIGS. 8 and 9, in the left acoustic unit 1L of the headphone device, the drive unit SPu-f ( RF), SPu-C (L), SPu-LF, SPu-LS, and SPu-f (RS). In this case, the drive unit SPu-LFE (L) is arranged below the position where the drive units SPu-C (L) and SPu-LF are arranged.
Further, in the right acoustic unit 1R of the headphone device, the drive units SPu-f (LF), SPu-C (R), SPu are arranged so that the center position of the sounding portion is along the horizontal virtual line H from the front to the rear. -RF, SPu-RS, SPu-f (LF) are arranged. Further, the drive unit SPu-LFE (R) is arranged below the position where the drive units SPu-C (R) and SPu-RF are arranged.

In the arrangement mode described above, first, drive units corresponding to channels other than LFEch are arranged along the same horizontal imaginary line H in the left and right acoustic units. This arrangement mode corresponds to the position of each channel sound source as 5.1ch surround.
That is, for example, on the left acoustic unit 1L side, the drive unit SPu-LS corresponding to the main audio component of LSch is arranged behind the drive unit SPu-LF corresponding to the main audio component of LFch. Further, a drive unit SPu-C (L) corresponding to Cch is arranged in front of the drive unit SPu-LF. Thus, it can be seen that the drive unit corresponding to the main sound component and the sound of the channel corresponding to the main sound component is arranged corresponding to the position of the channel sound source. Of the drive units corresponding to the sub audio component, the drive unit SPu-f (RF) corresponding to the front sound source is arranged on the front side with respect to the drive unit SPu-LF at the reference position, and the rear The drive unit SPu-f (RS) corresponding to the sound source is arranged behind the reference position.
On the right acoustic unit 1R side, the drive units SPu-f (RF), SPu-C (R), SPu-LF, SPu-LS, SPu- are arranged in a symmetrical relationship with the left acoustic unit 1L. f (RF) is arranged, and therefore the drive unit corresponding to the main audio component is arranged corresponding to the position of the channel sound source on the right acoustic unit 1R side, and as a sub audio component. The drive unit SPu-f (LF) corresponding to the front sound source is arranged in front of the reference position, and the drive unit SPu-f (LS) corresponding to the rear sound source is arranged in rear of the reference position. It has become.

  In this case, as described above, of the drive units arranged in the left and right acoustic units, the arrangement positions of the drive units SPu-LF and SPu-RF are used as references. That is, for the drive units SPu-LF and SPu-RF, positions where the output sound reaches the left and right ears and directions are set so as not to be biased forward or backward. This position is equivalent to the arrangement of the left and right drive units when a headphone device is configured as a normal L, R stereo, for example. In addition, the positional relationship in the front-rear direction for other drive units is set.

In addition, since the drive units SPu-f (RF) and SPu-f (LF) are in front of the reference position in each of the left and right acoustic units, the sound images as LFch and RFch are localized at appropriate positions in the front. The sound can be heard as described above with reference to FIG.
Further, depending on the fact that the drive units SPu-f (LF) and SPu-f (RF) are located behind the reference position in each of the left and right acoustic units, the drive units SPu-f (LF) and SPu-f (RF) are located at appropriate positions in the rear in accordance with the description of FIG. The sound image is localized and can be heard.
In addition to the LF, RF, LSch, and RSch sounds described above, the Cch and LFEch sounds are spatially synthesized in the acoustic unit and then reach the left and right ears. As a result, the listener can clearly feel the sound image localization by the sound source position corresponding to the channel configuration shown in FIG. 5, for example.

Furthermore, according to FIG. 8, in each acoustic unit, five drive units ([SPu-f (RF), SPu-C (L), SPu-LF) corresponding to other than the LFEch arranged along the virtual line H. , SPu-LS, SPu-f (RF)] [drive units SPu-f (RF), SPu-C (L), SPu-LF, SPu-LS, SPu-f (RF)], respectively. The angle is given along a curved surface that surrounds the ear, rather than being arranged in a plane, so that, for example, the arrangement position relationship of the drive units is closer to the sound source position in the 5.1ch surround channel configuration. The sound image localization feeling is made clearer.
As described above, the mounting angle or the like in the case where the drive units are arranged in a curved surface may be set by verifying a sense of sound image localization actually obtained.

By the way, by arranging the drive unit along the front-rear direction of the listener as shown in FIG. 9, the following operation can be obtained.
For example, in the left acoustic unit 1L, attention is paid to the positional relationship between the drive unit SPu-f (RF) corresponding to the RFch sub-sound component and the drive unit SPu-LF corresponding to the LFch main sound component. On the other hand, the drive unit SPu-f (RF) is located farther from the drive unit SPu-LF.
This means, for example, that the distance DS1 described above with reference to FIG. 4 exists between the drive unit SPu-f (RF) for the drive unit SPu-LF. Therefore, a time difference that the time for the sound to reach the left ear from the drive unit SPu-f (RF) is longer than the time for the sound to reach the left ear from the drive unit SPu-LF. The sound arrival time to the ear is the same for the drive unit SPu-LF and the symmetrical drive unit SPu-RF. As a signal characteristic of the sub audio component, it is necessary to give a difference in arrival time with respect to the main audio component. From the above, this difference in arrival time is calculated as a position between the drive unit SPu-f (RF) and the drive unit SPu-L. By the relationship, you can earn. Thus, as will be described later, in the present embodiment, it is possible to omit a delay unit in a system for outputting sound by the drive unit SPu-f (RF), and a simple signal processing system configuration can be realized. It is.
For the same reason, the drive unit SPu-f (LF) in the right acoustic unit 1R is also arranged with the same positional relationship as the drive unit SPu-f (RF). The drive unit SPu-f (RS) in the left acoustic unit 1L is also arranged behind the drive unit SPu-LS. Similarly, the drive unit SPu-f (LS) in the right acoustic unit 1R is also from the drive unit SPu-RS. Is also arranged rearward.

  Note that the measurement points in the space measurement ranges P1 and P2 shown in FIG. 6 are set in correspondence with the spatial arrangement positions of the drive units shown in FIGS. That is, the measurement points Prfl, Pcl, Plfl, Plsl, Prsl in the space measurement range P1 corresponding to the left ear are the drive units SPu-f (RF), SPu-C (L), SPu- in the left acoustic unit 1L, respectively. It should be set in consideration of correspondence with the arrangement positions of LF, SPu-LS, and SPu-f (RS). Similarly, the measurement points Plfr, Pcr, Prfr, Prsr, Plsr in the spatial measurement range P2 corresponding to the right ear are respectively drive units SPu-f (LF), SPu-C (R), It should be set in consideration of the correspondence with the arrangement positions of SPu-RF, SPu-RS, and SPu-f (LS).

FIG. 10 shows a modification of the arrangement of the drive units in the acoustic unit. In this figure, the same parts as those in FIG.
In FIG. 10, first, among the five drive units corresponding to channels other than the LFEch provided in the left acoustic unit 1L, the drive units SPu-f (RF), SPu-C (L), and SPu-LF are illustrated in FIG. 9, the drive units SPu-LS and SPu-f (RS) are arranged along a virtual horizontal line H similar to that of the virtual horizontal line Hu. It is arranged along the top. Similarly, also in the right acoustic unit 1R, the drive units SPu-f (LF), SPu-C (R), and SPu-RF are arranged along the virtual horizontal line H, and the drive units SPu-RS, SPu-f ( LS) is arranged along the virtual horizontal line Hu.
That is, in the 5.1ch surround channel configuration, the drive units corresponding to the main audio component and the sub audio component using the LSch and RSch as sound sources, which are positioned relative to the listening position, are positioned higher than the drive units of other channels. Is set to be.
For example, in the case where sound reproduction is performed by a speaker system that supports a multi-channel configuration such as an actual 5.1 channel surround, a speaker of a channel arranged at a position behind the listening position is set to the front with respect to the listening position. It is empirically known that a good sense of sound image localization can be obtained when installed at a position slightly higher than the speaker of the channel arranged at a certain position. The arrangement example of the drive unit shown in FIG. 10 is an application of this, and as a result, a better sound field can be obtained even in the headphone device of the present embodiment.
As shown in FIG. 10, when the position of the drive unit is changed in the height direction, the position in the height direction for each measurement point in the space measurement ranges P1 and P2 should be changed and set. It will be.

  By the way, as described above, the description of FIG. 7 is based on the assumption that the filter 11, the delay device 12 and the like indicated by the broken lines are omitted, and that the configuration is simplified. However, in the signal system shown in FIG. 7, a filter 11 for providing a frequency characteristic difference from the main sound is provided in the sub sound system in LFch, RFch, LSch, and RSch without being omitted. The filter 11 can be constituted by a digital filter, for example, but an analog filter is used as the filter 11 in consideration of the simplification and cost reduction of the signal processing system as much as possible. It is also possible.

FIG. 11 shows a configuration example of the filter 11 using an analog circuit.
In this figure, first, an inductor L1 is inserted in series at the first stage where a signal is input, and filter sections 11a, 11b, and 11c are sequentially connected to a subsequent stage of the inductor L1. It is supposed to be. The filter unit 11a is formed by connecting a series circuit including an inductor L2, a resistor R2, and a capacitor C2 and a parallel circuit including an inductor L3, a resistor R3, and a capacitor C3 as illustrated. The filter unit 11b is formed by connecting a series circuit including an inductor L4, a resistor R4, and a capacitor C4 and a parallel circuit including an inductor L5, a resistor R5, and a capacitor C5 as illustrated. The filter unit 11c is formed by connecting a parallel circuit including an inductor L6 and a resistor R6 and a series circuit including a resistor R7 and a capacitor C7 as illustrated.
FIG. 12 shows an example of the frequency characteristic of the sub-audio when the frequency characteristic of the main audio is set as a standard flat characteristic. As shown in the characteristic part A, the frequency characteristic of the sub-audio firstly, the voltage (amplitude) gradually decreases as the frequency range changes from low to high, and then the characteristic part B , C, a dip occurs at two certain frequency points in the mid-range. In a band higher than this, as shown by the characteristic portion D, the voltage gradually decreases.
The filter 11 shown in FIG. 11 inputs an audio signal (original audio signal) having a characteristic corresponding to the main audio component and gives the signal characteristic shown in FIG. 12, and the characteristic of the characteristic portion D is obtained by the inductor L1. , The characteristic of the characteristic part B is given by the filter part 11a, the characteristic of the characteristic part C is given by the filter part 11b, and the characteristic of the characteristic part A is given by the filter part 11c.

  Note that the configuration example of the filter 11 as an analog circuit shown in FIG. 11 is merely an example. For example, if the characteristics shown in FIG. The circuit configuration may be adopted.

  Further, for example, under the basic configuration shown in FIG. 3, a delay device 12 is provided together with the filter 11 for the sub audio component system. As described above, depending on the delay unit 12, it is intended to create a difference between the time until the main sound component reaches the one ear from the sound source and the time until the sub sound component reaches the other ear. The However, the configuration as the simple signal processing system shown in FIG. 7 shows a form in which the delay unit 12 is omitted for each of the sub-audio systems of LFch, RFch, LSch, and RSch. In other words, in the headphone sound reproduction system of the present embodiment, a corresponding delay time is obtained by the system itself that outputs the sub audio component as described below, and for this reason, the delay device can be omitted. .

First, the system to output the sub audio component is provided with the filter 11 for giving a frequency characteristic difference with respect to the main audio component as described above. As a general matter, a phase difference with respect to the input signal is produced by the signal passing through the filter. This phase difference can be viewed as a signal delay.
Further, as shown in FIGS. 4 and 8, the drive unit to output the secondary sound is the drive unit (SPu-L, SPu-R) (SPu-LR, SPu-RF) of the reference channel in the acoustic unit. ) With a certain distance (DS1), so that a time delay until reaching the ear is obtained.
In this way, in the headphone sound reproduction system of the present embodiment, a corresponding delay time is given in the path until the audio signal of the sub audio component reaches the ear as sound. Therefore, if the delay time obtained in this way falls within an error within an allowable range with respect to the delay time to be actually set by the delay device 12, the delay device 12 in the system can be omitted. That is why.

In the case of configuring a headphone sound reproduction system that supports 5.1ch surround, strictly speaking, as described above with reference to FIG. 23, for example, if LFch and RFch are used as a reference, this reference It is necessary to obtain a sound in which an appropriate transfer function is convoluted by giving a difference in signal characteristics of sounds of other channels (Cch, LSch, RSch) with respect to the channel.
However, in the configuration of FIG. 7, the filter for the main audio component is omitted for Cch, LSch, and RSch. That is, the filter that gives the signal characteristic difference with respect to the LFch and RFch sounds is omitted.
This is also because the drive unit corresponding to each output channel is individually arranged in the acoustic unit in the present embodiment. That is, in the present embodiment, as described above with reference to FIG. 8, for example, the drive units are arranged in correspondence with the sound source positions of the respective channels forming 5.1ch surround. This is a major factor in obtaining a stable sound image localization. In other words, the operation equivalent to giving a signal characteristic difference with respect to the sound of, for example, LFch and RFch is obtained by the positional relationship of the drive units in the acoustic unit. In the case of FIG. 7, the configuration equivalent to inserting Cch, LSch, and RSch filters 11-C, 11-LS, and 11-RS indicated by broken lines is obtained. It will be.
In FIG. 7, the Cch system is also shown in a form in which the delay device 12-C is omitted as indicated by a broken line. The Cch system can be treated as having no signal characteristic difference between the sounds reaching the left and right ears. For example, as a signal characteristic difference with respect to the main audio component of the reference LFch and RFch, the delay time difference Will also be included. The delay device 12-C is originally for accurately generating this delay time difference. However, the delay device 12-C can be omitted because of the arrangement position of the drive unit described above. . That is, the drive units SPu-C (L) and SPu-C (R) corresponding to the left and right Cch have a certain distance from the front with respect to the positions of the speaker units SPu-L and SPu-R, respectively. They are spaced apart, thereby providing a delay in the arrival time of the sound to each ear. Therefore, if the delay of the sound arrival time depending on the arrangement position of the drive unit is used, even if the delay device 12-C is omitted, the signal characteristics equivalent to the provision of the delay device 12-C can be obtained. Is.
Thus, as the headphone sound reproduction system of the present embodiment, in the signal system corresponding to each output channel, the filter and the delay device are omitted, and an analog circuit is adopted as the filter. Simplification of the configuration can be achieved. Thereby, for example, it is expected that a significant cost reduction will be achieved.

  Subsequently, as a simplification measure for the headphone sound reproduction system of the present embodiment, a configuration example of a headphone sound reproduction system of a drive unit reduction type in which the number of drive units in the sound unit is reduced will be described with reference to FIGS. This will be described with reference to FIG.

First, FIG. 13 shows a configuration example of a signal system as a headphone sound reproduction system of a drive unit reduction type. In this figure, the same parts as those in FIG.
As the signal system shown in this figure, synthesizers 13a, 13b, 13c, and 13d are provided.
First, depending on the synthesizer 13a, an audio signal in which the transfer function sHrfl corresponding to the subchannel component of RFch is to be convoluted, and an audio signal in which the transfer function sHcl corresponding to the sound of Cch reaching the left ear is to be convoluted. To be synthesized. The output of the synthesizer 13a is input to the drive unit SPu-f (RF) C provided in the left acoustic unit 1L as an audio signal of the output channel f (RF) + C.
Also, depending on the synthesizer 13b, an audio signal in which the transfer function sHlfr corresponding to the sub-audio component of LFch is to be convolved, and an audio signal in which the transfer function sHcr corresponding to the sound of Cch reaching the right ear is to be convoluted Are input to the drive unit SPu-f (LF) C provided in the right acoustic unit 1R as an audio signal of the output channel f (LF) + C.
Further, depending on the synthesizer 13c, the audio signal to be convolved with the transfer function sHrsl corresponding to the sub-channel audio component of RSch and the audio signal of LFEch to be output from the left acoustic unit 1L are synthesized and output channel f ( RS) + LFE audio signal is input to the drive unit SPu-f (RS) LFE provided in the left acoustic unit 1L.
Also, depending on the synthesizer 13d, the audio signal to be convolved with the transfer function sHlsr corresponding to the LSch sub-audio component and the LFEch audio signal to be output from the right acoustic unit 1R are synthesized, and the output channel f ( (LS) + LFE audio signal is input to the drive unit SPu-f (LS) LFE provided in the right acoustic unit 1R.

  In other words, in the present embodiment, there are originally six according to the left and right acoustic units, and among the twelve output channels, f (RF) and C (L), f (LF) and A set of C (R), f (RS) and LFE (L), f (LS) and LFE (R) is synthesized at the audio signal stage and output from a common drive unit. As a result, as can be seen from FIG. 13, there are four drive units provided in the left acoustic unit 1L and the right acoustic unit 1R. That is, in comparison with FIG. 7, the number of drive units is reduced by two in each of the left acoustic unit 1L and the right acoustic unit 1R, and the total is reduced from 12 to 8.

Moreover, the example of arrangement | positioning of the drive unit in an acoustic unit corresponding to the structure shown in the said FIG. 13 is shown in FIG.14 and FIG.15.
As shown in these drawings, first, in the left acoustic unit 1L, the drive units SPu-f (RF) C, SPu are arranged from the front to the rear so that the center position of the sounding portion is along the horizontal virtual line H. -LF, SPu-LS, SPu-f (RS) LFE are arranged.
Also in the right acoustic unit 1R, the drive units SPu-f (LF) C, SPu-RF, SPu-RS, SPu- are arranged from the front to the rear so that the center position of the sounding portion is along the horizontal imaginary line H. f (LS) LFE is arranged. At this time, the left drive units SPu-f (RF) C, SPu-LF, SPu-LS, SPu-f (RS) LFE, and the right drive units SPu-f (LF) C, SPu-RF, SPu-RS, The SPu-f (LS) LFE has a positional relationship that is symmetrical on the left and right.

Here, the sound source positions of the sound components of the respective channels to be output from the drive unit SPu-f (RF) C and the drive unit SPu-f (LF) C are supposed to be in front of the listener. . The drive unit SPu-f (RF) C and the drive unit SPu-f (LF) C are respectively positioned in front of the ear in the left acoustic unit 1L and the right acoustic unit 1R. It corresponds to the direction of arrival of the sound from the sound source. As a result, an appropriate sound image localization is obtained for the sounds of the LFch, RFch, and Cch channels including the sound components output from the drive unit SPu-f (RF) C and the drive unit SPu-f (LF) C. To be done.
Further, the other drive units SPu-f (RS) LFE and SPu-f (LS) LFE are arranged on the rear side of the ear, so that these drive units SPu-f (RS) LFE are arranged. The RSch sub-sound and the LSch sub-sound output from the SPu-f (LS) LFE also correspond to the arrival directions of the sound from the sound source positions of the RSch and LSch. Therefore, an appropriate sound image localization feeling can be obtained also for the RSch and LSch sounds. For the LFEch sound, as described above, there is no need to consider the sense of sound image localization due to its frequency characteristics.

By the way, as described above, in a multi-channel configuration, when audio components of different channels are synthesized at the stage of the audio signal, phase interference or the like causes sound image localization unlike the case of synthesis in space. There is a problem that it is easy to lead to damage. In view of this, the headphone unit reduction type headphone sound reproduction system described above also includes the above-mentioned problems due to its configuration.
However, in the configuration of the headphone sound reduction system of the headphone unit reduction type, for example, in a multi-channel configuration as 5.1 channel surround, the channel of the channel that is assumed to have as low correlation as possible with respect to the characteristics such as the waveform and the frequency band. By synthesizing the audio signal, the above-described problem is avoided.
In other words, in the above configuration, first, the RFch sub-sound component (f (RF)) and the Cch sound, or the LSch sub-sound component (f (LF)) and the Cch sound are synthesized. For example, according to an actual 5.1ch surround sound source, if Cch is playing back a voice of a person or the like located in the center of the screen, the voices, sounds, etc. of the people around that are on LFch or RFch In many cases, the reproduction contents of LFch or RFch and Cch are different. That is, when viewed as an audio signal, it can be generally said that the correlation between the waveforms of LFch, RFch and Cch is low.
Also, since the LFEch sound is concentrated in a very low frequency compared to the sound of other channels, the correlation with respect to the frequency band is very low even when contrasted with, for example, the LSch and RSch sub-voices. .
In this way, by synthesizing an audio signal with low correlation in signal characteristics, the possibility of phase interference is reduced, and with this, there is also a phenomenon that the sense of sound image localization is impaired Less likely to occur. That is, the listener can listen to the sound in a state where a good sound image localization is maintained.

FIG. 16 shows a modification of the drive unit reduction type headphone sound reproduction system regarding the arrangement of the drive units in the sound unit.
The arrangement of the drive units shown in this figure is obtained by applying the arrangement example shown in FIG. 10 to a headphone device of a drive unit reduction type. That is, as illustrated, first, among the drive units provided in the left acoustic unit 1L, the drive units SPu-f (RF) C and SPu--LF are arranged along the virtual horizontal line H as in FIG. On the other hand, the drive units SPu-LS and SPu-f (RS) LFE that output sound components corresponding to the channel serving as the sound source position behind the listener are set at positions higher than the virtual horizontal line H by a predetermined amount. It is arranged along the virtual horizontal line Hu. Similarly, also in the right acoustic unit 1R, the drive units SPu-f (LF), C (R), and SPu-RF are arranged along the virtual horizontal line H, and the drive units SPu-RS and SPu-f (LS). The LFE is arranged along the virtual horizontal line Hu. With such an arrangement, a better sound field feeling can be obtained as described with reference to FIG.

  The setting of the measurement points in the space measurement ranges P1 and P2 corresponding to this drive unit reduction type configuration is also shown in FIG. 15 (or FIG. 16) and the arrangement of the drive units viewed from the plane direction shown in FIG. It is made to correspond to the arrangement mode of the drive unit as seen from the side direction shown. In this case, for the measurement points corresponding to a plurality of audio components synthesized and output from the same single drive unit, the same appropriate position is set.

In addition, the configuration for simplifying the configuration of the signal system in FIG. 7 has been described so far. However, in the present application, on the contrary, the purpose is to reproduce a very faithful sound field. It is not impeded that the signal system is configured.
In this case, for example, the filter 11 and the delay device 12 indicated by broken lines in FIG. 7 are actually provided to set appropriate passband characteristics and delay time, and between the main audio component and the sub audio component. The signal system is configured such that a strict signal characteristic difference is given, that is, a correspondingly accurate transfer function is convoluted. In this case, for example, if a digital filter is used for the filter 11 as well, the accuracy becomes high.

  Further, in FIG. 7, the signal system of the main audio components of LFch and RFch serving as a reference is not provided with a filter or a delay device. As described above, for LFch and RFch, for example, it is intended to easily obtain the required signal characteristics by utilizing the acoustic characteristics originally supposed to be possessed by the headphone device. However, strictly speaking, for example, as shown in FIG. 5, there is also a transfer function corresponding to the sound source position for the main audio components of LFch and RFch. The feeling of localization of the sound source becomes better by being folded in. From this, the signal system of the main audio component of LFch and RFch may be provided with a filter (and a delay unit) so that appropriate signal characteristics can be obtained. In this case, the LFch and RFch main sounds that are given through the filter (and delay unit) as described above for sounds corresponding to other output channels other than the main audio components of the LSch and RFch. The signal characteristic difference may be obtained with reference to the signal characteristic of the component.

Here, the headphone sound reproduction system of the present embodiment includes a headphone device that is actually worn on the head of the listener and a signal processing circuit corresponding to the signal system shown in FIGS. And should be configured. As a combination of the actual configurations of the headphone device and the signal processing circuit unit, for example, one is a system configuration in which the headphone device and the signal processing device unit including the signal processing circuit unit are separated. Can be considered. In this case, transmission of the audio signal from the signal processing unit to the headphone device may be performed, for example, by wire, or may be performed wirelessly by adopting a predetermined wireless transmission / reception method using infrared rays, radio waves, or the like. May be.
As another configuration, a configuration in which a signal processing circuit unit is built in and integrated with a predetermined portion such as an acoustic unit or a headband unit configuring the headphone device main body is also conceivable.

By the way, as a single headphone device, a configuration in which an acoustic unit is provided with an independent drive unit corresponding to multi-channel is already known. The configuration of this headphone device is shown in FIG. 24 and FIG. This headphone device is also intended to support 5.1ch surround as an audio source.
In the headphone device shown in these drawings, first, as shown in FIG. 24, in left acoustic unit 1L, drive unit SPu-LF corresponding to LFch is arranged at the front position, and Cch is handled at the rear upper position. The drive unit SPu-C corresponding to the LSch is disposed at the lower rear position, and the drive unit SPu-LFE corresponding to the LFEch is disposed on the lower side.
In the right acoustic unit 1R, the drive unit SPu-RF corresponding to the RFch is disposed at the front position, the drive unit SPu-C corresponding to the Cch is disposed at the rear upper position, and the rear lower side is further disposed. The drive unit SPu-RS corresponding to LSch is arranged at the position, and the drive unit SPu-LFE corresponding to LFEch is arranged on the lower side.
Then, as shown in FIG. 25, the LFch and RFch audio signals are directly input to the drive units SPu-LF and SPu-RF, respectively, and the same Cch audio is supplied to the left and right drive units SPu-C. The signal branched is directly input, and the LSch and RSch audio signals are directly input to the drive units SPu-LS and SPu-RS, respectively. Also, the LFEch audio signal is directly input to the left and right drive units SPu-LFE.

  That is, in the headphone device shown in FIGS. 24 and 25, for the time being, according to the sound source position of the 5.1ch surround channel, LFch, LSch, RFch, and RSch are distributed to the left sound unit and the right sound unit. For the Cch, the left and right acoustic units are provided with a drive unit because of the necessity of localization at the center of the head. A drive unit is provided in the acoustic unit. In addition, for example, the audio signals of the respective channels forming the 5.1ch surround sound source are directly input to each drive unit without performing any filter processing or delay processing.

  In such a configuration, the sound of each channel constituting 5.1ch surround is output from different independent drive units. However, only the sound of the original audio signal of the corresponding channel is emitted from each drive unit, and the main audio and the relationship of the appropriate signal characteristics for each channel are given as in this embodiment. The auxiliary audio component cannot be heard with both ears. Further, even when looking at the arrangement along the front-rear direction for the drive units other than the LFEch that should give a sense of orientation, for example, the arrangement of other drive units with respect to the virtual line H set with reference to the position of the drive unit SPu-LF in FIG. In particular, regularity is not seen and it is appropriate. For this reason, in the headphone device shown in FIGS. 24 and 25, although the sound of each channel can be clearly distinguished to some extent, the sound image localization appropriate for 5.1ch surround is performed as in this embodiment. It can be said that it is very difficult to get a feeling.

Here, the headphone sound reproduction system of the present embodiment includes a headphone device that is actually worn on the head of the listener and a signal processing circuit corresponding to the signal system shown in FIGS. And should be configured. As a combination of the actual configurations of the headphone device and the signal processing circuit unit, for example, one is a system configuration in which the headphone device and the signal processing device unit including the signal processing circuit unit are separated. Can be considered. In this case, transmission of the audio signal from the signal processing unit to the headphone device may be performed, for example, by wire, or may be performed wirelessly by adopting a predetermined wireless transmission / reception method using infrared rays, radio waves, or the like. May be.
In addition, as another configuration, a configuration in which a signal processing circuit unit is built in and integrated with a predetermined portion that constitutes the headphone device main body is also conceivable.

Note that the present invention should not be limited to the configuration as the embodiment described so far.
First, the physical arrangement of the drive unit to be provided for the acoustic unit is conceivable in addition to those illustrated so far and the variations described so far.
In addition, as an embodiment, a configuration corresponding to 5.1ch surround is given as an example, but the present invention can also be applied to other types of multichannel configurations such as 7.1ch surround.

It is a figure which shows the basic acoustic model corresponding to the headphone sound reproduction system as embodiment of this invention. It is a figure which shows the example of a setting of the measurement position corresponding to the sound component of each sound source in the acoustic model of FIG. It is a figure which shows the structural example of the audio | voice signal processing system about the headphone sound reproduction | regeneration system corresponding to FIG. FIG. 4 is a diagram illustrating an exemplary arrangement of drive units in a headphone device corresponding to the configuration of FIG. 3. It is a figure which shows the acoustic model of 5.1ch surround corresponding to the headphone sound reproduction system of embodiment. It is a figure which shows the example of a setting of the measurement position corresponding to the sound component of each sound source in the acoustic model of FIG. It is a figure which shows the structural example of the audio | voice signal processing system of the headphone sound reproduction system of embodiment corresponding to a 5.1ch surround system. It is a figure which shows typically the example of an arrangement | positioning aspect of the drive unit in the headphone apparatus of embodiment corresponding to a 5.1ch surround system from a plane direction. It is a figure which shows typically the example of the arrangement | positioning aspect of the drive unit in the headphone apparatus of embodiment corresponding to a 5.1ch surround system from a side surface direction. It is a figure which shows typically the other example of an arrangement | positioning aspect about the drive unit in the headphone apparatus of embodiment corresponding to a 5.1ch surround system from a side surface direction. It is a circuit diagram which shows the structural example of the filter with which the audio | voice signal processing system of the headphone sound reproduction system of embodiment is equipped. It is a figure which shows the example of a characteristic of the filter shown in FIG. It is a figure which shows the structural example of a drive unit reduction | decrease type as an audio | voice signal processing system of the headphone sound reproduction system of embodiment corresponding to a 5.1ch surround system. It is a figure which shows typically the example of an arrangement | positioning aspect of the drive unit in the headphone apparatus corresponding to FIG. 13 from a plane direction. It is a figure which shows typically the example of an arrangement | positioning aspect of the drive unit in the headphone apparatus corresponding to FIG. 13 from a side surface direction. It is a figure which shows typically the example of another arrangement | positioning aspect about the drive unit in the headphone apparatus corresponding to FIG. 13 from a side surface direction. It is a figure which shows the example of an acoustic model in the case of listening to one sound source. It is a figure which shows the signal characteristic difference of the main audio | voice component and a sub audio | voice component in the acoustic model of FIG. It is a figure which shows the example of an acoustic model in the case of listening to two sound sources. It is a figure which shows the structural example of the audio | voice signal processing system of the headphone sound reproduction | regeneration system corresponding to the acoustic model shown in FIG. FIG. 21 is a diagram schematically illustrating an arrangement example of drive units in the headphone device corresponding to FIG. 20 in a planar direction. It is a figure which shows the general acoustic model of 5.1ch surround. It is a figure which shows the structural example of the audio | voice signal processing system of the headphone sound reproduction | regeneration system corresponding to the acoustic model shown in FIG. It is a figure which shows the example of arrangement | positioning aspect of the drive unit in the headphone apparatus corresponding to a multichannel structure from a plane direction. It is a figure which shows the example of arrangement | positioning aspect of the drive unit in the headphone apparatus corresponding to a multichannel structure from a side surface direction.

Explanation of symbols

  1L left acoustic unit, 1R right acoustic unit, 11 (11-LS, 11-RS, 11-f (RS), 11-f (LS), 11-C, 11-f (LF), 11-f (RF )) Filter, 12 (12- (RF), 12-f (RS), 12- (LF), 12-f (LS)) Delay device, SPu-f (RF), SPu-C (L), SPu -LF, SPu-LS, SPu-f (RS), SPu-LFE (L), SPu-f (LF), SPu-C (R), SPu-RF, SPu-RS, SPu-f (LS), SPu-LFE (R), SPu-f (RS) LFE (L), SPu-f (LS) LFE (L), SPu-f (RF) C, SPu-f (LF) C drive unit

Claims (6)

A plurality of drive unit pairs corresponding to the left and right ears are provided for each of a plurality of channels constituting a predetermined channel configuration,
At least one of the set of drive units is
The main audio signal corresponding to the main audio component that is supposed to reach the position corresponding to one ear from the virtual sound source position of the corresponding channel is input and reproduced and output. One-side drive unit for main audio provided to be heard by the ears of
The sub-audio signal corresponding to the sub-audio component that is supposed to reach the position corresponding to the other ear from the virtual sound source position of the corresponding channel is input and reproduced and output. And a sub-audio compatible one-sided drive unit provided so that it can be heard by the ears of
Sub-audio signal characteristic imparting means for obtaining the sub-audio signal by giving a signal characteristic corresponding to a difference between predetermined characteristics of the sub-audio component to the main audio component to the main audio signal;
Headphone sound reproduction system characterized by the above. The sub audio signal characteristic providing means includes:
In order to give the sub audio signal a signal characteristic corresponding to the difference between the predetermined characteristics of the sub audio component with respect to the main audio component, it is obtained by eliminating the influence of the pinna on the main audio component and the sub audio component. A predetermined characteristic obtained on the basis of the obtained head-related transfer function,
The headphone sound reproduction system according to claim 1. According to each channel constituting the predetermined channel configuration, a primary audio-compatible single-side drive unit and / or a secondary audio-compatible single-side drive unit for each predetermined channel forming a left-ear side drive unit group provided to be heard by the left ear,
The primary audio-compatible single-side drive unit and / or the secondary audio-compatible single-side drive unit for each predetermined channel forming the right-ear side drive unit group provided to be heard by the right ear,
The virtual sound source position for each corresponding channel is provided in a predetermined positional relationship along the front-rear direction according to the positional relationship with respect to the listening position.
The headphone sound reproduction system according to claim 1. In at least one of the left ear drive unit group and the right ear drive unit group,
Of the channels constituting the predetermined channel configuration, for the drive unit that should reproduce and output the sound corresponding to the channel whose virtual sound source position is behind the listening position, the sound corresponding to the other channel is reproduced and output. It is arranged to be higher than the power drive unit,
The headphone sound reproduction system according to claim 3. Among the channels forming the predetermined channel configuration, a set of one drive unit is provided so as to correspond to a plurality of channels that satisfy a predetermined condition.
The left-ear and right-ear drive units that form a set of drive units corresponding to the plurality of channels respectively synthesize the main audio component and / or the sub audio component to be output corresponding to the plurality of channels. Input the resulting audio signal,
The headphone sound reproduction system according to claim 1. A plurality of drive unit pairs corresponding to the left and right ears are provided for each of a plurality of channels constituting a predetermined channel configuration,
At least one of the set of drive units is
The main audio signal corresponding to the main audio component that is supposed to reach the position corresponding to one ear from the virtual sound source position of the corresponding channel is input and reproduced and output. One-side drive unit for main audio provided to be heard by the ears of
Signal processing for providing a signal characteristic as a sub audio component according to a difference with respect to a predetermined characteristic with respect to the main audio component, which is assumed to reach a position corresponding to the other ear from the virtual sound source position of the corresponding channel. A sub-audio-corresponding one side provided so that the sub-audio signal obtained by executing the main audio signal is input and reproduced and output, and the reproduced and outputted sound is heard by the other ear. Consisting of a drive unit,
A headphone device characterized by that.

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