JP2008028467A - Audio reproducing device, and reproducing method and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce center channel signals at a clear and uniform sense of sound field, even in a system equipped with a center speaker having insufficiently high capability of reproducing sounds of a low and high frequency bands and used for a vehicle. <P>SOLUTION: An audio reproducing device reproduces a multi-channel audio signal including right/left and center channel signals. The center channel signal has its signal level detected by a signal level detecting section, and is divided into a plurality frequency bands including a mid-frequency band by a band dividing section. The plurality of frequency bands may be, for example, two frequency bands such as medium and low/high frequency bands and may be three frequency bands such as low, medium and high frequency bands. Also, it may be four frequency bands including an LFE signal band. A level control unit adjusts the level of each band in response to at least any one of the signal level of the center channel signal and volume setting by a user. Further, the components of bands other than the medium frequency band after level adjustment are added to the right and left channel signals and reproduced by the right and left speakers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for reproducing a multi-channel audio signal including left and right channels and a center channel.

  Conventionally, a multi-channel stereo system is known. This multi-channel stereo system supplies a multi-channel audio signal to a plurality of speakers to realize a sound field space full of realism. The 5.1 channel signal, which is a typical multi-channel audio signal, includes left and right front channel signals, center channel signals, left and right rear channel signals, and LFE (Low Frequency Effect) signals, and these signals correspond to six signals. Play on the speaker.

  In recent years, in-vehicle speaker systems that support multi-channel audio signals have also been developed. However, it is difficult for a vehicle-mounted center speaker to have sufficient reproduction capability in the low and high sound ranges due to restrictions such as installation location in the vehicle interior and reproduction capability. From this point of view, Patent Document 1 proposes a method of dividing the center channel signal into two bands, a low frequency range and a mid-high range, reproducing the low range with a front speaker, and reproducing the mid-high range with a center speaker. is doing. With this method, even when a small center speaker is used, good reproduction is possible.

JP 2003-61198 A

  As described above, the method described in Patent Document 1 has an effect of compensating for the shortage of the bass reproduction capability of the center speaker. However, in general, in an in-vehicle speaker system, the front and rear left and right speakers are often multi-way structures using a tweeter, but the center speaker may have a multi-way structure due to restrictions on the installation location. Have difficulty. Therefore, even if the method of Patent Document 1 is adopted, there is a problem that the reproduction of the sound field becomes non-uniform because the center speaker and the rear or front speaker have different high-frequency reproduction capability and sound quality tendency. Moreover, it is necessary to compensate for the lack of reproduction capability of the center speaker even in the high sound range.

  Examples of the problems to be solved by the present invention include those described above. An object of the present invention is to reproduce a center channel signal with a clear and uniform sound field feeling even in a system equipped with a center speaker that does not have a very high reproduction capability in a low sound range and a high sound range such as in-vehicle use.

  The invention according to claim 1 is an audio reproducing apparatus, wherein an input unit that receives an audio signal including a left channel signal, a right channel signal, and a center channel signal, and a signal level detection that detects a signal level of the center channel signal. According to at least one of a signal level of the center channel signal and a volume setting value by a user. A level control unit that controls the level of the center channel signal in a range other than the range, an addition unit that adds the center channel signal in a range other than the mid range to the left channel signal and the right channel signal, and the addition Left channel signal and right channel signal output from the unit, Each time, characterized in that it comprises an output unit that outputs a center channel signal output from the level controller.

  The invention according to claim 6 is an audio reproduction method, an input step of receiving an audio signal including a left channel signal, a right channel signal and a center channel signal, and a detection step of detecting a signal level of the center channel signal. The center channel signal is divided into a plurality of bands including a mid-range, and the mid-range and other than the mid-range according to at least one of the signal level of the center channel signal and the volume setting value by the user A level control step of controlling the level of the center channel signal in the sound range, an addition step of adding the center channel signal of a sound range other than the middle range to the left channel signal and the right channel signal, and the addition step The resulting output left channel signal and right channel Channel signal, and characterized in that it comprises an output step of outputting the output center channel signal obtained by the level control step.

  The invention according to claim 7 is an audio reproduction program executed on a computer, wherein an input unit that receives an audio signal including a left channel signal, a right channel signal, and a center channel signal, and a signal level of the center channel signal are set. In accordance with at least one of a signal level detection unit for detecting, a band dividing unit for dividing the center channel signal into a plurality of bands including a mid range, a signal level of the center channel signal and a volume setting value by a user, the mid range And a level control unit for controlling the level of the center channel signal in a range other than the mid range, an addition unit for adding the center channel signal in a range other than the mid range to the left channel signal and the right channel signal, and The left channel output from the adder Signal and right channel signal, and is characterized by causing the computer to function as an output unit, which outputs the center channel signal output from the level controller.

  In a preferred embodiment of the present invention, the audio reproducing apparatus includes an input unit that receives an audio signal including a left channel signal, a right channel signal, and a center channel signal, and a signal level detection unit that detects a signal level of the center channel signal. A band dividing unit that divides the center channel signal into a plurality of bands including a mid range, and other than the mid range and the mid range according to at least one of a signal level of the center channel signal and a volume setting value by a user A level control unit that controls the level of the center channel signal in the sound range, an addition unit that adds the center channel signal in a sound range other than the middle sound range to the left channel signal and the right channel signal, and the addition unit Output left channel signal and right channel signal, In, and an output unit that outputs a center channel signal output from the level controller.

  The audio reproduction device reproduces a multi-channel audio signal including left and right and center channel signals. The signal level of the center channel signal is detected by the signal level detection unit, and the center channel signal is divided into a plurality of bands including a mid-range by the band division unit. The plurality of bands may be, for example, two bands of a middle sound range and a low / high sound range, or may be three bands of a low sound range, a middle sound range, and a high sound range. Further, four bands including the LFE signal band may be used.

  The level control unit adjusts the level of each band according to at least one of the signal level of the center channel signal and the volume setting by the user. Further, the band components other than the mid-tone range after the level adjustment are added to the left and right channel signals and reproduced by the left and right speakers. Therefore, even when the center speaker's low / high sound reproduction capability is not sufficient, such as in-vehicle speaker systems, the center channel signal is clearly and favorably sensed by controlling the levels appropriately using the left and right speakers. Can be played.

  In a preferred example, the level control unit controls the level of the center channel signal in the mid range and a range other than the mid range according to both the signal level of the center channel signal and the volume setting value by the user. .

  In one aspect of the audio playback device, the level control unit increases the level of the center channel signal in the middle sound range by a first predetermined amount when the signal level of the center channel signal is smaller than a predetermined value, The level of the center channel signal in the range other than the middle range is increased by a second predetermined amount that is greater than the first predetermined amount. Generally, it is said that the human auditory sensitivity is lower in the low and high sound ranges than in the mid sound range. Therefore, when the level of the center channel signal is low, the center channel signal can be clearly reproduced by increasing the level of the mid range and further increasing the level of the low / high range.

  In another aspect of the audio reproduction device, the level control unit decreases the first and second predetermined amounts as the signal level of the center channel signal increases. When the level of the center channel signal is increased, the difficulty of listening to the user is improved correspondingly, so the level increase by the level control unit is reduced.

  In another aspect of the audio reproduction device, the level control unit decreases the first and second predetermined amounts as the volume setting value increases. When the volume setting value by the user increases, the difficulty of listening to the user is improved accordingly, so the level increase amount by the level control unit is reduced.

  In another embodiment of the present invention, an audio reproduction method includes an input step of receiving an audio signal including a left channel signal, a right channel signal and a center channel signal, a detection step of detecting a signal level of the center channel signal, A band dividing step of dividing the center channel signal into a plurality of bands including a mid range, and a range other than the mid range and the mid range according to at least one of a signal level of the center channel signal and a volume setting value by a user Obtained by the level control step for controlling the level of the center channel signal, the addition step for adding the center channel signal in a range other than the middle range to the left channel signal and the right channel signal, and the addition step. Left channel signal and right channel output Signals, as well, and an output step of outputting the output center channel signal obtained by the level control step.

  In another embodiment of the present invention, an audio reproduction program executed on a computer detects an input unit that receives an audio signal including a left channel signal, a right channel signal, and a center channel signal, and a signal level of the center channel signal. In accordance with at least one of a signal level detection unit, a band division unit that divides the center channel signal into a plurality of bands including a mid range, a signal level of the center channel signal and a volume setting value by a user, the mid range and the A level control unit for controlling the level of the center channel signal in a range other than the mid range, an addition unit for adding the center channel signal in a range other than the mid range to the left channel signal and the right channel signal, and Left channel signal output from the adder And right channel signal, and an output unit that outputs a center channel signal output from the level controller, as to function the computer. By executing this audio playback program on a computer, the above-described audio playback apparatus can be realized. Note that the above audio reproduction program can be suitably stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 shows a schematic configuration of an audio reproducing apparatus according to the first embodiment of the present invention. The audio playback device 1 receives a multi-channel audio signal from a DVD playback unit 2 as a source signal source. Hereinafter, “channel” is also expressed as “CH”. The multi-CH audio signal includes a left front CH signal SFL, a center CH signal SCE, a right front CH signal SFR, a left rear CH signal SRL, a right rear CH signal SRR, and an LFE signal SLFE.

  The left front CH signal SFL is supplied to the right front speaker 24FL via the adder 20 and the amplifier 23. The right front CH signal SFR is supplied to the left front speaker 24FR via the adder 21 and the amplifier 23. The left rear CH signal SRL and the right rear CH signal SRR are supplied to the left rear speaker 24RL and the right rear speaker 24RR via the amplifier 23, respectively. The LFE signal SLFE is supplied to the woofer 24W via the low pass filter (LPF) 22 and the amplifying unit 23.

  The center CH signal SCE is supplied to the signal level detection unit 11 and the band division unit 13. The signal level detector 11 detects the signal level of the center CH signal SCE and supplies it to the level control signal generator 12. The band dividing unit 13 is a part that divides the center CH signal SCE into a plurality of bands. In this embodiment, the band dividing unit 13 divides the center CH signal SCE into three bands of a high sound range, a middle sound range, and a low sound range. Specifically, the band dividing unit 13 includes a high pass filter (HPF) 14, a band pass filter (BPF) 15, and a low pass filter (LPF) 16.

  The HPF 14 extracts the high frequency range component of the center CH signal SCE and supplies it to the high frequency range signal level control unit 17. The high sound range signal level control unit 17 controls the level of the high sound region component of the center CH signal SCE, and supplies the signal after the level control to the adding units 20 and 21.

  The BPF 15 extracts the mid-range component of the center CH signal SCE and supplies it to the mid-range signal level control unit 18. The mid-range signal level control unit 18 controls the level of the mid-range component of the center CH signal SCE, and supplies the level-controlled signal to the center speaker 24C via the amplification unit 23. Therefore, only the mid-range component of the center CH signal SCE is supplied to the center speaker 24C via the amplifier 23.

  The LPF 16 extracts the low frequency range component of the center CH signal SCE and supplies it to the low frequency range signal level control unit 19. The bass signal level controller 19 controls the level of the bass component of the center CH signal SCE and supplies the level-controlled signal to the adders 20 and 21.

  The adding unit 20 adds the left front CH signal SFL, the output signal of the high sound range signal level control unit 17, and the output signal of the low sound range signal level control unit 19 to the left front speaker 24 FL via the amplifying unit 23. Supply. Therefore, the left front speaker 24FL is subjected to level control by the left front CH signal SFL, the high-frequency component of the center CH signal SCE level-controlled by the high-frequency signal level control unit 17, and the low-frequency signal level control unit 19. The sum of the center CH signal SCE made and the low frequency range component is supplied via the amplifier 23.

  The adding unit 21 adds the right front CH signal SFR, the output signal of the high sound range signal level control unit 17, and the output signal of the low sound range signal level control unit 19 to the right front speaker 24 FR via the amplifying unit 23. Supply. Therefore, the right front speaker 24FR is subjected to level control by the right front CH signal SFR, the high-frequency component of the center CH signal SCE level-controlled by the high-frequency signal level control unit 17, and the low-frequency signal level control unit 19. The sum of the center CH signal SCE made and the low frequency range component is supplied via the amplifier 23.

  The control unit 3 includes, for example, a microcomputer and controls operations of the DVD playback unit 2, the level control signal generation unit 12, the input unit 4, the display unit 5, the amplification unit 23, and the like. The input unit 4 is an operation input unit provided in the audio reproduction device 1 and can take various forms such as a remote control and an operation knob provided in the audio reproduction device 1. In the present embodiment, the input unit 4 particularly includes a playback volume setting unit by the user. That is, when the user operates the input unit 4 to adjust the volume, the input unit 4 supplies the volume setting value set by the user to the control unit 3. The display unit 5 displays information relating to a song being played or content, and is typically composed of a liquid crystal panel or the like.

  The control unit 3 supplies a control signal SC0 to the DVD playback unit 2 in accordance with a user input to the input unit 4, such as a DVD playback instruction, and controls playback by the DVD playback unit 2. Further, the control unit 3 supplies the control signal SC1 corresponding to the volume setting value input by the user to the input unit 4 to the amplification unit 23 and the level control signal generation unit 12. The amplification unit 23 controls the amplification degree of the signal of each channel according to the control signal SC1.

  The level control signal generator 12 generates the control signals SC <b> 2 to SC <b> 4 based on at least one of the signal level output from the signal level detector 11 and the control signal SC <b> 1 supplied from the controller 3. Specifically, the level control signal generation unit 12 supplies the control signal SC2 to the high sound range signal level control unit 17, supplies the control signal SC3 to the mid sound range signal level control unit 18, and supplies the control signal SC4 to the low sound range signal. This is supplied to the level controller 19. The high sound range signal level control unit 17, the mid sound range signal level control unit 18, and the low sound range signal level control unit 19 are based on the supplied control signals SC2 to SC4, respectively. Controls the level of the bass component.

  Next, level control of each band component by the level control signal generator 12 will be described in detail. In a multi-audio channel signal corresponding to a source such as a movie, the center CH signal often includes speech such as speech. In a vehicle-mounted speaker system or the like, it is difficult to make the center speaker have sufficient reproduction capability in a low and high sound range. Therefore, when a movie or the like is reproduced, it becomes difficult to hear words and the like included in the center CH signal. From this point of view, in the present embodiment, the center CH signal is divided into bands, the mid-range component is reproduced from the center speaker, and the low-frequency component and the high-frequency component are mixed with the left and right front CH signals to reproduce the low-high range. Playback is performed from the left and right front speakers, which have higher capabilities than the center speaker. In this way, the mid-range component of the center CH signal including movie speech is output from the center speaker, so that the user does not feel uncomfortable. Further, since the low and high frequency range components are reproduced from the left and right front speakers, the center CH signal can be clearly reproduced as a whole.

  In addition, in the present embodiment, the level of each component of the high, middle, and low sound ranges of the center CH signal is adjusted based on the signal level of the center CH signal and the volume setting by the user. In an in-vehicle environment, a problem of masking due to noise occurs remarkably in reproduced sound from a speaker. The difficulty of listening to movies and other lines under noise is a major obstacle to watching movies. Further, it has been conventionally known that low sound and high sound become harder to hear as the reproduction volume is lower due to human auditory characteristics. Therefore, in the present embodiment, the level of each band component of the high frequency range, the middle frequency range, and the low frequency range of the center CH signal is dynamically adjusted based on the signal level of the center CH signal and the volume setting by the user. To solve the problem.

  The basic policy for level control of each component of the center CH signal is as follows.

  (Policy 1) When the signal level of the center CH signal is small, the level of the mid range component is increased, and the levels of the low range and the high range are increased beyond the mid range. This is because the sensitivity of the low range and the high range is lower than the sensitivity of the mid range due to human auditory characteristics, so that the level of the low range and the high range is increased to make it easier to hear lines and the like. .

  (Policy 2) As the signal level of the center CH signal increases, the level increase amount of each band component is reduced. This is because the higher the signal level of the original center CH signal, the easier it is to hear lines and the like, and therefore the level adjustment may be less.

  (Policy 3) The level increase amount of each band component is reduced as the volume setting value by the user increases. This is because if the volume of the center CH signal is large due to the user's volume adjustment, the lines and the like are easy to hear, and the level adjustment may be small.

  (Policy 4) When the signal level of the center CH signal is large and the volume setting value by the user is large, the level of the mid-range component is not increased and the level is not changed or decreased. This is because when the original signal level of the center CH signal is large and the level increases due to the volume setting, it is necessary to prevent clipping and distortion of the center speaker.

  Based on the above concept, the level control signal generator 12 controls the level of each band component. Specifically, the level control signal generation unit 12 performs numerical calculation based on the signal level of the center CH signal detected by the signal level detection unit 11 and the volume setting value given from the control unit 3, or in advance. By referring to the prepared table, the level control amount of each band component is determined and supplied to the level control units 17 to 19 as control signals SC2 to SC4.

  FIG. 2 shows an example of a table used when the level control signal generation unit 12 performs level control using a table. In FIG. 2, for example, when the center CH signal level and the volume setting value are both small (cell G), the level of the mid range is increased as shown in the above policy 1, and the level of the high range and the low range are set to the mid range. Increase the level more than When the volume setting value is the same (for example, cells B, E, and H), the level increase amount of each band is smaller as the center CH signal level is larger in accordance with the above policy 2. When the center CH signal level is the same (for example, cells D, E, and F), the level increase amount of each band is smaller as the volume setting value is larger according to the above policy 3. Further, when both the center CH signal level and the volume setting value are large (cell C), the level of the mid-range component is not increased according to the above policy 4. Note that FIG. 2 is merely an example of a level control table.

  As described above, in this embodiment, the middle sound range of the center CH signal is reproduced from the center speaker, the low sound range and the high sound range are reproduced by the front speakers having high reproduction ability, and the signal level of each band is set to the center. It is configured to dynamically change according to the CH signal level and the volume setting value. This makes it possible to reproduce the center CH signal including speech that is particularly important in movies and the like with a clear and uniform sound field feeling even in an environment such as noise.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 3 shows a schematic configuration of an audio playback apparatus 1a according to the second embodiment. The same components as those of the audio reproducing device 1 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The audio reproduction device 1a according to the second embodiment is different from the first embodiment in that the band dividing unit 33 divides the center CH signal into two bands, specifically, a low / high sound range and a middle sound range. The other points are basically the same as in the first embodiment.

  In FIG. 3, the band dividing unit 33 includes a subtractor 34 and a BPF 35. The BPF 35 extracts the mid range component from the center CH signal SCE and supplies it to the mid range signal level control unit 18 and the subtractor 34. The mid-range level control unit 18 controls the level of the mid-range component of the center CH signal SCE based on the control signal SC 3 supplied from the level control signal generation unit 12 and supplies it to the amplifying unit 23. On the other hand, the subtractor 34 subtracts the middle sound range component output from the BPF 35 from the center CH signal SCE to generate a low / high sound range component, and supplies the low / high sound range signal level controller 36. The low / high range signal level control unit 36 controls the level of the low / high range component based on the control signal SC5 supplied from the level control signal generation unit 12, and sends the level-controlled signal to the addition units 20 and 21. Supply. As a result, the low / high range component after level control is mixed with the left front CH signal SFL and the right front CH signal SFR. That is, the low and high frequency components of the center CH signal SCE are reproduced from the left and right front speakers.

  In the second embodiment, compared to the first embodiment, the band division is set to two bands, so that the configurations of the band dividing unit and the level control unit can be simplified.

[Third embodiment]
Next, a third embodiment of the present invention will be described. FIG. 4 shows a schematic configuration of an audio playback device 1b according to the third embodiment. The same components as those of the audio reproducing device 1 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The audio reproducing device 1b according to the third embodiment is configured to divide the center CH signal SCE into four bands, ie, low, medium, high sound range, and LFE signal band, to reproduce from different speakers. Specifically, the LFE band signal level control unit 41 extracts an LFE signal band component from the center CH signal SCE and supplies it to the adding unit 42. The adder 42 adds the LFE signal band component extracted from the center CH signal SCE to the LFE signal SLFE, and supplies the result to the woofer 24W via the LPF 22 and the amplifier 23. The LFE band signal level control unit 41 controls the level of the LFE signal band component based on the control signal SC6 supplied from the level control signal generation unit 12. This control signal SC6 is also generated based on the center CH signal level and the volume setting value, like the other control signals SC2 to SC4.

  In the third embodiment, compared to the first embodiment, the reproduction division of the low frequency component of the center CH signal can be shared by the front speaker and the woofer by dividing the band into four bands.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described. FIG. 5 shows a schematic configuration of an audio playback device 1c according to the fourth embodiment. The same components as those of the audio reproducing device 1 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. Note that FIG. 5 shows only the components that process the center CH signal, and the signal processing portions of the other channels are not shown.

  In the fourth embodiment, functions equivalent to those of the first embodiment are realized with different configurations. In the first embodiment, after the center CH signal is divided into low, medium, and high sound ranges, level control is performed for each band. On the other hand, in the fourth embodiment, band division is performed after the level of each band of the center CH signal is controlled using a variable equalizer.

  Specifically, the center CH signal from the DVD playback unit 2 is supplied to the variable equalizer 52. The variable equalizer 52 adjusts the level of each band of the center CH signal based on the control signal supplied from the level control signal generation unit 12 and supplies the adjusted center CH signal to the HPF 53, the BPF 54, and the LPF 55. The BPF 54 supplies the mid-range component of the center CH signal to the center speaker 24C. The adder 56 receives the high frequency range component of the center CH signal from the HPF 53 and also receives the low frequency range component of the center CH signal from the LPF 55, adds them, and supplies them to the left and right front speakers 24FL and 24FR.

  Although not shown in FIG. 5, as in FIG. 1, the left front CH signal SFL is supplied to the left front speaker 24FL, and the right front CH signal SFR is supplied to the right front speaker 24FR. . Further, the level control signal generation unit 12 determines the level adjustment amount for each band of the variable equalizer 52 based on the center CH signal level and the volume setting value.

[Modification]
In each of the above-described embodiments, the level of the center CH signal is adjusted based on both the center CH signal level and the volume setting value, but the application of the present invention is not limited to this. The level adjustment may be performed based on only one of them.

  Further, in each of the embodiments described above, components in the sound range other than the middle sound range of the center CH signal are reproduced by the front speakers. Instead, they are reproduced by the rear speakers or both the front speakers and the rear speakers. It is good.

  The present invention is particularly effective for a system in which the low / high sound range reproduction capability of the center speaker is not so high, such as an in-vehicle system. However, the present invention is not limited to the in-vehicle system, and is not limited to the in-vehicle system. Widely applicable to multi-channel audio products such as receivers and multi-channel decoders.

It is a block diagram which shows schematic structure of the audio reproducing apparatus of 1st Example. It is an example of the table used for a level control signal generation. It is a block diagram which shows schematic structure of the audio reproduction apparatus of 2nd Example. It is a block diagram which shows schematic structure of the audio reproduction apparatus of 3rd Example. It is a block diagram which shows schematic structure of the audio reproduction apparatus of 4th Example.

Explanation of symbols

1, 1a, 1b, 1c Audio playback device 2 DVD playback unit 3 Control unit 4 Input unit 5 Display unit 13, 33 Band division unit 11 Signal level detection unit 12 Level control signal generation unit 24 Speaker

Claims (8)

An input for receiving an audio signal including a left channel signal, a right channel signal and a center channel signal;
A signal level detector for detecting a signal level of the center channel signal;
A band dividing unit that divides the center channel signal into a plurality of bands including a mid range;
A level control unit for controlling the level of the center channel signal in a sound range other than the midrange and the midrange according to at least one of a signal level of the center channel signal and a volume setting value by a user;
An adder for adding the center channel signal in a range other than the middle range to the left channel signal and the right channel signal;
An audio reproduction apparatus comprising: an output unit that outputs a left channel signal and a right channel signal output from the addition unit, and a center channel signal output from the level control unit.   The level control unit controls the level of the center channel signal in the middle range and a range other than the middle range according to a signal level of the center channel signal and a volume setting value by a user. 2. The audio playback device according to 1.   When the signal level of the center channel signal is smaller than a predetermined value, the level control unit increases the level of the center channel signal in the middle range by a first predetermined amount, and the center channel signal in a range other than the mid range 3. The audio reproducing apparatus according to claim 2, wherein the level of is increased by a second predetermined amount larger than the first predetermined amount.   4. The audio reproduction apparatus according to claim 3, wherein the level control unit decreases the first and second predetermined amounts as the signal level of the center channel signal increases.   The audio playback device according to claim 3 or 4, wherein the level control unit decreases the first and second predetermined amounts as the volume setting value increases. An input process for receiving an audio signal including a left channel signal, a right channel signal, and a center channel signal;
A detection step of detecting a signal level of the center channel signal;
A band dividing step of dividing the center channel signal into a plurality of bands including a mid range;
A level control step of controlling the level of the center channel signal in the middle range and a range other than the middle range according to at least one of the signal level of the center channel signal and the volume setting value by the user;
An adding step of adding the center channel signal in a range other than the mid range to the left channel signal and the right channel signal;
And an output step of outputting the output left channel signal and right channel signal obtained by the addition step and the output center channel signal obtained by the level control step. Method. An audio playback program executed on a computer,
An input for receiving an audio signal including a left channel signal, a right channel signal and a center channel signal;
A signal level detector for detecting a signal level of the center channel signal;
A band dividing unit that divides the center channel signal into a plurality of bands including a mid range;
A level control unit for controlling the level of the center channel signal in the middle range and a range other than the middle range in accordance with at least one of the signal level of the center channel signal and the volume setting value by the user;
An adder for adding the center channel signal in a range other than the middle range to the left channel signal and the right channel signal; and
An audio reproduction program that causes the computer to function as an output unit that outputs a left channel signal and a right channel signal output from the addition unit and a center channel signal output from the level control unit.   A storage medium storing the audio reproduction program according to claim 7.

Images