JP2013034094A - Acoustic characteristic controller and electronic musical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To approximate spread of an acoustic image when allowing a listener to listen to a performance sound of an electronic piano via headphones, to spread of acoustic image when allowing the listener to listen to the sound via a speaker.SOLUTION: Band division parts 11L and 11R divide output signals L and R of an electronic piano 90 into three bands. A signal generation part 12 extracts MID component signals M, M, and Mand SIDE component signals S, S, and Sfrom band division signals L, R, L, R, L, and Rwhich belong to each band, mixes the signals M, M, and Mand the signals S, S, and Sin different ratios to generate component mixed signals LMX, RMX, LMX, RMX, LMX, and RMX, and supplies the signals LMX, LMX, and LMXto a left headphone unit 94L of headphones 93 and the signals RMX, RMX, and RMXto a right headphone unit 94R.

Description

  The present invention relates to a technique for controlling a sound image of a sound when a performance sound of an electronic keyboard instrument is heard through headphones.

  Some electronic pianos have a jack for connecting headphones. In this type of electronic piano, when it is not desired to leak the performance sound to the surroundings, the headphone is attached to the performer's head, and the headphone plug is inserted into the jack of the electronic piano, and the performance is performed in this state. When the electronic piano detects a keystroke with the headphones plugged into the jack, it reads out the sound data of the left and right channels of the keystroke sound from the sound source, and reads the sound data of the left and right channels from the left and right channels. The sound signal is supplied to the left and right headphone units of the headphones. The left headphone unit of the headphones emits the sound signal of the left channel supplied from the electronic piano toward the player's left ear, and the right headphone unit of the headphones outputs the sound signal of the right channel supplied from the electronic piano. Sounds towards the performer's right ear. Thereby, the performer can perform the performance without leaking the performance sound of the electronic piano to the surroundings.

JP 58-30300 A US Patent Publication No. 2010/0246832 US Pat. No. 5,751,817

Fritz Menzer, Christoph Farrer, Stereoto Binaural Conversion Using International Coherence Matching, Audio Engineering Technology Convention Paper 7986, United Kingdom of Great Britain and Northern Ireland, the128th Convention April 22, 2010

However, when headphones are used to listen to the performance sound of an electronic piano, there is a problem that it is difficult to obtain a natural sound spread. The reason is as follows. In general, the sound data of the left and right two channels stored in the sound source of an electronic piano is the sound data produced by mixing and adjusting the keystroke sound of each key picked up by a plurality of microphones arranged around the acoustic piano. It has become. Therefore, as shown in the example of FIG. 2A, the sound of the sound signal of the left channel and the sound signal of the right channel of the electronic piano 190 are moved to the left front and right front positions of the performer (FIG. 2A). In the example of (2), when the player P is listened to through the two speakers 200L and 200R placed at a position 30 degrees to the left and 30 degrees to the right when viewed from the front of the player, the left speaker 200L The sound of the left channel sound signal emitted from the right ear ER is heard not only by the left ear EL but also the right channel sound signal emitted from the right speaker 200R as well as the right ear ER. Crosstalk, a phenomenon that can be heard in EL, occurs. Here, the sound transmitted from the left speaker 200L to the left ear EL and AL, the sound transmitted from the right speaker 200R to the right ear ER and AR, and the sound transmitted from the left speaker 200L to the right ear ER and _{AL CR,} from the right speaker 200R If the sound transmitted to the left ear EL is AR _CR , the time difference corresponding to the difference in sound path length between the time when the sound AL reaches the left ear EL and the time when the sound AL _CR reaches the right ear ER. ΔTL occurs. Similarly, a time difference ΔTR corresponding to the difference in sound path length is generated between the time when the sound AR reaches the right ear ER and the time when the sound AR _CR reaches the left ear EL. Therefore, in this case, the performer P feels that there is a sound image having a left-right spread including the speakers 200L and 200R in a certain direction of the left speaker 200L and the right speaker 200R when viewed from the player P.

  On the other hand, as shown in the example of FIG. 2B, when the performance sound of the electronic piano 190 is heard through the headphones 193, crosstalk does not occur. In this case, the performer can hear the sound AL of the left headphone unit 194L and the sound AR of the right headphone unit 194R from both the left and right directions across the player. Therefore, in this case, the performer does not feel that there is a sound image in front of himself / herself, but feels that he / she is in a sound image that greatly expands to the left and right.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide technical means capable of obtaining a natural sound spread when headphones are used for listening to performance sounds of an electronic piano. And

  In order to solve the above problems, the present invention divides a left and right two-channel input signal into a plurality of bands, and outputs band divided signals of two left and right channels belonging to each divided band, and the band division For the left and right two-channel band-divided signals of each band divided by the means, the SIDE that is the difference between the MID component signal that is the sum of the left and right two-channel band-divided signals of the band and the right and left two-channel band-divided signals Generate component signals, mix MID component signals and SIDE component signals of each band to generate left and right two-channel component mixed signals for each band, and transfer the left channel component mixed signal of each band to the left headphone unit of the headphones And a signal generating means for outputting a right channel component mixed signal of each band to the right headphone unit of the headphone. Providing sexual controller.

  In the present invention, for each band obtained by dividing the left and right two-channel input signals, the left and right two-channel component mixed signals obtained by mixing the MID component signal and the SIDE component signal of the band are supplied to the left headphone unit and the right headphone unit. Output. Therefore, by appropriately determining the ratio of the SIDE component signals in the component mixed signals of the left and right two channels in each band, the sound image that the player feels when using headphones to listen to the performance sound is moderately Narrowing can create a more natural sense of sound expansion.

  Here, there are Patent Documents 1 to 3 and Non-Patent Document 1 as documents disclosing a technique for controlling the spread of stereo sound of two left and right channels. However, the sound field varying device disclosed in Patent Document 1 is a sum of a signal M and a signal S from a sum M (M = L + R) and a difference S (S = LR) of two left and right channel sound signals L and R. A signal M + S and a difference signal MS are generated, and these signals M + S and MS are added to the original sound signals L and R after giving a predetermined amount of delay, and the added signals L + (M + S) and R + are added. (MS) is output. In the techniques of Patent Documents 2 and 3, the head-related transfer function in the section from the sound source to the left and right ears is convolved with the left and right two-channel stereo audio signals. Non-Patent Document 1 calculates the position of a sound image for each divided band Δf and convolves the head-related transfer function so as to be localized at this position, and is assumed to be applied to a keyboard instrument as in the present invention. It is not a thing. Therefore, Patent Documents 1 to 3 and Non-Patent Document 1 describe the present invention which is a technique for controlling a sound image by band division of left and right two-channel sound signals and addition, subtraction, and amplification of the divided band division signals. Is different.

It is a figure which shows the structural example of the electronic musical instrument containing the acoustic characteristic control apparatus and electronic piano which are one Embodiment of this invention. It is a figure for demonstrating the problem of a prior art.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of an electronic musical instrument including an acoustic characteristic control device 10 and an electronic piano 90 according to an embodiment of the present invention. In this electronic musical instrument, a headphone 93 attached to the head of the player P and an electronic piano 90 played by the player P are connected via the acoustic characteristic control device 10. In this electronic musical instrument, the left and right channel output signals L and R of the electronic piano 90 are supplied to the left headphone unit 94L and the right headphone unit 94R of the headphone 93 through signal processing by the acoustic characteristic control device 10. As shown in FIG. 1, 88 keys 91 -k (k = k = from the lowest note number key 91-1 to the highest note number key 91-88) are formed on the top surface of the housing 99 of the electronic piano 90. 1 to 88) are arranged side by side in the left-right direction. The sound source 92 of the electronic piano 90 includes 88 sets of sound data DL-k (k = 1 to 88) and DR-k (k = 1 to 88) corresponding to each of the keys 91-k (k = 1 to 88). ) Is recorded. A set of sound data DL-k and DR-k corresponding to one key 91-k is sound data obtained by mixing and adjusting keystroke sounds collected by a plurality of microphones arranged around the acoustic piano. When the key 91-k on the upper surface of the housing 99 is pressed, the electronic piano 90 reads the sound data DL-k and DR-k corresponding to the key 91-k that has been pressed from the sound source 92, and this sound data. DL-k and DR-k are output to the acoustic characteristic control apparatus 10 as sound signals L and R of two left and right channels.

Next, the configuration of the acoustic characteristic control device 10 will be described. The acoustic characteristic control device 10 includes band division units 11L and 11R and a signal generation unit 12. The band dividing unit 11L divides the input signal L of the left channel given from the electronic piano 90 into three bands, a low band, a middle band, and a high band, and a band divided signal L _L belonging to the low band, The band division signal L _M to which it belongs and the band division signal L _H to which it belongs are output. The band dividing unit 11R divides the input signal R of the right channel given from the electronic piano 90 into three bands, a low band, a middle band, and a high band, and a band divided signal R _L belonging to the low band, The band division signal R _M to which it belongs and the band division signal R _H that belongs to the high band are output.

The signal generation unit 12 uses the low frequency band division signal L _{L for} the band division signals L _L , L _M , L _H , R _L , R _M , and R _H of each band divided by the band division units 11L and 11R. and both signals and MID component signal _{M L} is the sum of _{R L L L} and SIDE component signal which is the difference between _{R L S L,} MID component signal which is the sum of the band-divided signals _{L M} and _{R M} midrange _{M M} And the difference between the two signals L _H and R _H , the SIDE component signal S _M that is the difference between the two signals L _M and R _M , and the MID component signal _MH that is the sum of the high frequency band division signals L _H and R _H A certain SIDE component signal _SH is generated. On top of that, the signal generator 12, low, mid, and each band of the MID component signal _M L of the high frequency, _{M M,} and _{M H} and SIDE component signal _S L, _{S M,} and the _{S H,} The left or right two-channel component mixed signals LMX _L , LMX _M , LMX _H , RMX _L , RMX _M , and RMX _H for each band are generated by mixing the sum or difference of the same band. The sum of the component mixed signals LMX _L , LMX _M , and LMX _H is mixed and output to the left headphone unit 94L, and the sum of the component mixed signals RMX _L , RMX _M , and RMX _H of the right channel of each band is mixed. To the right headphone unit 94R.

More specifically, the signal generation unit 12 includes a low frequency processing unit 13 _L , a mid frequency processing unit 13 _M , a high frequency processing unit 13 _H , and addition units 14 L and 14 R. The role of each unit _{13 L, 13 M, 13 H} , 14L, and 14R are as follows. Lowpass processor 13 _L generates SIDE component signal _{S L} is the difference between the band-divided signals _{L L} and _R both signals and MID component signal _{M L} is the sum of the _{L L L} and _{R L} of the low frequency signal M _L and signal S _L are mixed at mixing ratios α _L : (1-α _L ² ) ^1/2 and α _L :-( 1-α _L ² ) ^1/2 respectively, and left and right two-channel component mixed signal LMX It generates _L and RMX _L, and outputs a signal LMX _L and signals the RMX _L was amplified each with a unique gain beta _L and gamma _L LMX _L × beta _L and RMX _L × gamma _L. More specifically, the low frequency processing unit 13 _L includes an adding unit 1 _L , a subtracting unit 2 _L , an amplifying unit 3 _L , an amplifying unit 4 _L , an adding unit 5 _L , a subtracting unit 6 _L , an amplifying unit 7 _L , and an amplifying unit. Part _8L is included. Addition section _{1 L} adds the signal _{L L} and the signal _{R L,} and outputs the sum _L L + _{R L} as the signal _{M L.} Subtraction unit _{2 L} subtracts the signal _{R L} from the signal _{L L,} and outputs the subtraction result _L L -R _L as the signal _{S L.} Amplifying section _{3 L} outputs a signal _{M L} × alpha _L obtained by amplifying the output signal _{M L} of the adder _{1 L} with mixing ratio alpha _L. Amplifying unit _{4 L} the subtraction section _{2 L} of the output signal _{S L} mixing ratio (1-α _L ^{2) 1/2} amplified signal _{S L × (1-α L} 2) for outputting a ^1/2. In the present embodiment, the mixing ratio of the mixing ratio alpha _L and amplifier unit _{4 L} of the amplifying part ^{_{3 L (1-α L 2}} ) 1/2 of the magnitude relationship _{α L> (1-α L} 2) 1 Set to ^{/ 2} . Since the mixing ratio α _L is originally 0 <α _L <1, the setting range of the mixing ratio α _L of the amplifying unit 3 _L is 1> α _L > (1/2) ^{1/2 and} the mixing ratio of the amplifying unit 4 _L ( The setting range of 1-α _L ² ) ^1/2 is (1/2) ^1/2 > (1-α _L ² ) ^1/2 > 0. Adding unit _{5 L,} the amplification unit _{3 L} output signal of the output signal _{M L} × _{α L} an amplifier _{4 L} of _{S L × (1-α L} 2) 1/2 adds, the addition result _{M L} × alpha _L + S _L × (1−α _L ² ) ^1/2 is output as the signal LMX _L. Subtraction unit _{6 L,} the amplification unit _{3 L} of the output signal _{M L} × output signal of the amplifier _{4 L} from _{α L S L × (1-} α L 2) 1/2 subtracted, the subtraction result _{M L} × alpha _L− S _L × (1−α _L ² ) ^1/2 is output as the signal RMX _L. Amplifying portion _{7 L} outputs a signal LMX _L × _{β L} obtained by amplifying the output signal LMX _L of the adder _{5 L} with a gain beta _L. Amplifying unit _{8 L} outputs a signal RMX _L × _{γ L} obtained by amplifying the output signal RMX _L of the subtraction unit _{6 L} with a gain gamma _L.

The mid-band processing unit 13 _M generates an MID component signal M _M that is the sum of the mid-band band-divided signals L _M and R _M and a SIDE component signal S _M that is the difference between the two signals L _M and R _M. such as the ratio of the signal _{M M} occupying the components mixed signal of two left and right channels of the band LMX _M and RMX _M is smaller than the ratio of the signal _{M L} occupying the components mixed signal LMX _L and RMX _L of left and right channels of the low-pass The signal M _M and the signal S _M are mixed at a mixing ratio α _M : (1-α _M ) ^1/2 (α _M is a value smaller than α _L ) and α _M :-( 1-α _M ) ^1/2. The left and right two-channel component mixed signals LMX _M and RMX _M are generated, and the signals LMX _M × β _M and RMX _M × γ _{M are obtained} by amplifying the signals LMX _M and RMX _M with their inherent gains β _M and γ _M , respectively. Is output. More specifically, the mid-band processing unit 13 _M includes an adding unit 1 _M , a subtracting unit 2 _M , an amplifying unit 3 _M , an amplifying unit 4 _M , an adding unit 5 _M , a subtracting unit 6 _M , an amplifying unit 7 _M , and an amplifying unit. Part 8 _M is included. Addition section _{1 M} adds the signal _{L M} and the signal _{R M,} and outputs the sum _L M + _{R M} as the signal _{M M.} Subtraction unit _{2 M} subtracts the signal _{R M} from the signal _{L M,} and outputs the subtraction result _L M -R _M as the signal _{S M.} Amplifying section _{3 M} outputs signal _{M M} × alpha _M obtained by amplifying the output signal _{M M} of the adder _{1 M} in mixing ratio alpha _M. Amplifying unit _{4 M} outputs the subtraction unit of _{2 M} output signals _{S M} The mixing ratio (1-α _M) amplified signal _{S M} × at ^{_{1/2 (1-α M) 1/2}} . Adding unit _{5 M} includes an amplifier unit ₃ outputs signal _{M M} × _{α M} and the output signal _{S M} × amplification section _{4 M (1-α M)} of _M ^1/2 adds, the addition result _{M M} × alpha _M + S _M × (1−α _M ) ^1/2 is output as the signal LMX _M. Subtraction unit _{6 M} includes an amplifier unit ₃ outputs signal _{M M} × alpha output signal of the amplifier _{4 M} from _{M S M × (1-α} M) of _M ^1/2 subtracted, the subtraction result _{M M} × alpha _M -S _M × (1-α _M ) ^1/2 is output as the signal RMX _M. Amplifying portion _{7 M} outputs a signal LMX _M × _{β M} obtained by amplifying the output signal LMX _M of the adder _{5 M} with a gain beta _M. Amplifying section _{8 M} outputs the signal RMX _M × _{γ M} obtained by amplifying the output signal RMX _M of the subtraction unit _{6 M} a gain gamma _M.

High-frequency processing unit 13 _H generates the SIDE component signal _{S H} is the difference between the band-divided signals _{L H} and _{R H} is the sum of the MID component signal _{M H} and both signals _{L H} and _{R H} of the high band, the as the ratio of the signal _{M H} occupying the components mixed signal of two left and right channels of the band LMX _H and RMX _H is approximately the same as the ratio of the signal _{M L} occupying the components mixed signal of two left and right channels of the low-LMX _L and RMX _L Do mixing ratio alpha _M: respectively ^{_{(1-α M) 1/2 (}} α H is alpha _L substantially equal) and _{α M :-( 1-α M)} 1/2 the signal _{M H} and the signal _{S H} Signals LMX _H × β _H and RMX _H × γ are generated by mixing to generate component mixed signals LMX _M and RMX _M of left and right channels, and amplifying the signals LMX _H and RMX _H with inherent gains β _H and γ _H , respectively. _H is output. More specifically, the high frequency processing unit 13 _H includes an adding unit 1 _H , a subtracting unit 2 _H , an amplifying unit 3 _H , an amplifying unit 4 _H , an adding unit 5 _H , a subtracting unit 6 _H , an amplifying unit 7 _H , and an amplifying unit. Part _8H is included. Addition unit _{1 H} adds the signal _{L H} and the signal _{R H,} and outputs the sum _L H + _{R H} as a signal _{M H.} Subtraction section _{2 H} subtracts the signal _{R H} from the signal _{L H,} and outputs the subtraction result _L H -R _H as the signal _{S H.} Amplifying section _{3 H} outputs a signal _{M H} × alpha _H obtained by amplifying the output signal _{M H} of the adder _{1 H} at a mixing ratio alpha _H. Amplifying portion _{4 H} includes subtraction section ₂ signal was amplified by the output signal _{S H} to the mixing ratio (1-α _H ^{2) 1/2} of the _{H S H × (1-α} H 2) outputs ^1/2. Adding unit _{5 H} includes an amplifier unit ₃ outputs signal _{S H × (1-α H} 2) of the output signal _{M H} × _{α H} an amplifier _{4 H} of _H ^1/2 adds, the addition result _{M H} × alpha _{H + S H × (1-} α H) outputs ^1/2 as signal LMX _H. Subtraction unit _{6 H} includes an amplifier unit _{3 H} output signal _{M H} × alpha output signal of the amplifier _{4 H} from _{H S H × (1-α} H) of ^1/2 subtracted, the subtraction result _{M H} × _{α H -S H × (1-α H} ) outputs ^1/2 as signal RMX _H. Amplifying portion _{7 H} outputs a signal LMX _H × _{β H} obtained by amplifying the output signal LMX _H of the adder _{5 H} with a gain beta _H. Amplifying unit _{8 H} outputs a signal RMX _H × _{γ H} obtained by amplifying the output signal RMX _H of the subtraction unit _{6 H} a gain gamma _H.

The adder 14L adds the output signals LMX _L × β _L , LMX _M × β _M , LMX _H × β _H of the amplifiers 7 _L , 7 _M and 7 _H , and the addition result LMX _L × β _L + LMX _M × β _M + LMX _H × β _H is output as a signal LMX to the left headphone unit 94L. The adder 14R adds the output signals RMX _L × γ _L , RMX _M × γ _M , RMX _M × γ _H of the amplifiers 8 _L , 8 _M , and 8 _H , and the addition result RMX _L × γ _L + RMX _M × γ _M + RMX _H × γ _H is output as a signal RMX to the right headphone unit 94R. The left and right two-channel sound signals LMX and RMX generated by the above procedure are emitted as sounds to the left and right ears of the player P from the left and right headphone units 94L and 94R.

The above is the details of the configuration of the present embodiment. According to this embodiment, the following effects can be obtained.
First, in the present embodiment, the low-frequency, MID component signal _{M L} and the SIDE component signal _{S L} and the component obtained by mixing a mixed signal LMX _L and respectively outputs the RMX _L to the left and right headphone units 94L and 94R To do. Further, for the middle range, component mixed signals LMX _M and RMX _M obtained by mixing the MID component signal M _M and the SIDE component signal S _M are output to the left and right headphone units 94L and 94R, respectively. Further, for the high-frequency, and it outputs the MID component signal _{M H} and SIDE component signal _S component mixed signal obtained by mixing the _H LMX _H and RMX _H on the left and right headphone units 94L and 94R. Therefore, according to the present embodiment, the feeling of expansion of the sound image felt when the player P uses the headphones 93 to listen to the performance sound of the electronic piano 90 is moderately reduced, and a natural sound expansion feeling can be created. .

Secondly, in the present embodiment, for the middle range, the ratio of the MID component signal M _M occupying the left and right two-channel component mixed signals LMX _M and RMX _M of the corresponding band is a low-frequency and high-frequency left-right two-channel component. mixed signal LMX _L, and RMX _L, accounted MID component signal _M becomes smaller such mixing ratios than the ratio of _{L α M: (1-α} M) 1/2 (α M <α L ≒ α H) and alpha _M :-( _{1-α M)} for generating a ^1/2 MID component signal _{M H} and SIDE component signal _S component mixed signal of each mix to the left and right 2 channel _M LMX _M and RMX _M. Here, when the proportion of the MID component signal M in the left and right two-channel component mixed signals LMX and RMX in a certain band decreases, the sound image created by the component mixed signals LMX and RMX in that band becomes wider. Therefore, according to the present embodiment, sound images created by the low-frequency component mixed signals LMX _L and RMX _L and the high-frequency component mixed signals LMX _H and RMX _H are created by the mid-frequency component mixed signals LMX _M and RMX _M. It becomes relatively narrower than the sound image to be played. The keys 91-k (k = 1 to 88) of the electronic piano 90 are arranged such that those with a low note number are on the left and those with a high note number are on the right. For this reason, the input signals L and R when the player P presses the left key 91-k includes many low-frequency components, and the input when the player P presses the front key 91-k. The signals L and R contain a lot of mid-frequency components, and the input signals L and R when the player P has pressed the right key 91-k contain a lot of high-frequency components. Therefore, according to the present embodiment, the sound image when the player P strikes the left or right key 91-k is narrower than the sound image when the player P strikes the front key 91-k, which is more natural. Can give the player P a pleasant audibility.

Third, in the present embodiment, the low-frequency component mixed signals LMX _L and RMX _L , the mid-frequency component mixed signals LMX _M and RMX _M , and the high-frequency component mixed signals LMX _H and RMX _H are set for each. Amplified with gains β _L , γ _L , β _M , γ _M , β _H , γ _H , and left channel component mixed signals LMX _L × β _L , LMX _M × β _M , LMX _H × after this amplification β _H and right channel component mixed signals RMX _L × γ _L , RMX _M × γ _M and RMX _H × γ _H are output to the left and right headphone units 94L and 94R, respectively. Here, for example, when the gain β _L of the low-frequency left-channel component mixed signal LMX _L is larger than the gain γ _{L of the} low-frequency right-channel component mixed signal RMX _L , the performer P has the left key I feel that the sound image that I feel when I hit 91-k is on the left as a whole. When the gain β _H of the high-frequency left-channel component mixed signal LMX _H is smaller than the gain γ _{H of} the high-frequency right-channel component mixed signal RMX _H , the performer P has the right key 91-k. I feel that the sound image that I feel when I hit the key is on the right as a whole. When the gain β _M of the left mixed channel component signal LMX _M and the gain γ _M of the right mixed signal component RMX _M of the middle band are substantially the same, the player P has the central key 91-k. I feel that the sound image that I feel when I hit the key is closer to the center as a whole. Therefore, in the present embodiment, for example, the gains β _L and γ _L (β _L >) in which the ratio of the left and right channel component mixed signals LMX _L and RMX _L in the low frequency range becomes larger than the left channel component mixed signal LMX _L. A gain such that the left and right two-channel component mixed signals LMX _M and RMX _M are amplified by γ _L ) and the ratio of the left channel component mixed signal LMX _M and the right channel component mixed signal RMX _M is substantially equal. A gain β that amplifies the signals by β _M and γ _M (β _M ≈γ _M ), respectively, and reduces the ratio of the left and right channel component mixed signals LMX _H and RMX _H to the left channel component mixed signal LMX _H. By amplifying each of _H and γ _H (β _H <γ _H ), the direction of the key 91-k pressed by the player P on the electronic piano 90 and the key 91 felt by the player P are displayed. The direction of the sound image of −k can be matched to give the player P a natural audibility.

Fourth, in the present embodiment, MID component signal _{M L} and the SIDE component signal _{S L} mixing ratio _{α L: (1-α L} 2) 1/2 , and the mixing ratio ^{_{α L :-( 1-α L 2}} ) Mixing by ^1/2 , the MID component signal M _M and the SIDE component signal S _M are mixed in a mixing ratio α _M : (1-α _M ² ) ^1/2 and a mixing ratio α _M :-( 1-α _M ² ) ^{1 / 2} and mixing the MID component signal _MH and the SIDE component signal _SH at a mixing ratio α _H : (1-α _H ² ) ^1/2 and a mixing ratio α _H :-( 1-α _H ² ) ^1/2 . Mix. Here, α _L and (1-α _L ² ) ^1/2 sum of squares, α _L and-(1-α _L ² ) ^1/2 sum of squares, α _M and (1-α _M ² ) ^1/2 sum of squares, α _M and-(1-α _M ² ) ^1/2 sum of squares, α _H and (1-α _H ² ) ^1/2 sum of squares, and α _H and- The sum of squares of (1-α _H ² ) ^1/2 is 1. Therefore, according to the present embodiment, it is possible to control only the sound image without changing the magnitude (energy amount) of the performance sound felt by the player P.

<Other embodiments>
Although one embodiment of the present invention has been described above, the present invention may have other embodiments. For example, it is as follows.
(1) In the embodiment described above, the left and right channel output signals L and R of the electronic piano 90 are each divided into three bands. However, the signals L and R may be divided into two or four or more bands. For example, the signals L and R are divided into 88 bands that are the same as the keys 91-k (k = 1 to 88) of the electronic piano 90, and when a certain key 91-k is pressed, the key 91-k that is pressed. The ratio of the MID component signal M and the SIDE component signal S in the component mixed signals LMX and RMX in each band may be controlled so that the center of the sound image spread is located at the position k.

(2) In the above embodiment, the gains β _L , γ _L , β _M , γ _M , β _H , γ _H for the component mixed signals LMX and RMX of the left and right channels in each band are used as the movement of the player's head. You may make it change in conjunction. More specifically, when the performer's head faces the left side with respect to the front electronic piano 90, the left and right two-channel component mixed signals LMX _L , RMX _L , LMX _M , RMX _M , LMX _H , RMX _H controls the gains β _L , γ _L , β _M , γ _M , β _H , γ _H so that the sound image created by RMX _H moves to the right, and the player's head is in front of the electronic piano 90. When turning to the right side, gain β _L , so that the sound image created by the left and right channel component mixed signals LMX _L , RMX _L , LMX _M , RMX _M , LMX _H , RMX _{H of} each band moves to the left side. γ _L , β _M , γ _M , β _H , and γ _H may be controlled.

(3) In the above embodiment, the present invention is applied to the control of the output sound of the electronic piano 90 which is an electronic keyboard instrument. However, the present invention may be applied to control of output sound of an electronic keyboard instrument other than the electronic piano 90, such as an electronic pipe organ. Further, the present invention may be applied to control of output sound of an electronic musical instrument that simulates a musical instrument (for example, drum, chime, etc.) having a plurality of types of sound sources with different pitches.

(4) In the above embodiment, the acoustic characteristic control device 10 is interposed between the electronic piano 90 and the headphones 93. However, stereo audio signals of performance sounds of the electronic piano 90 and other electronic keyboard instruments (for example, EFM (Eight-to-fourteen modulation) or MP3 (MPEG Audio
The acoustic characteristic control device 10 may be interposed between the playback device that reproduces Layer-3)) and the headphones 93. Moreover, it is good also as a structure which incorporated the acoustic characteristic control apparatus 10 in this reproducing | regenerating apparatus. Alternatively, the electronic piano 90 and the acoustic characteristic control device 10 may be housed in the same casing to constitute one electronic musical instrument.

(5) In the above embodiment, the signal of the low-pass _{M L} and the signal _{S L,} the signal of the middle band _{M M} and signal _{S M,} the signal _{M H} and the signal _{S H} midrange, different from the mixing ratio of the above-described embodiment The signals mixed at an arbitrary mixing ratio may be used as left and right two-channel component mixed signals LMX _L , RMX _L , LMX _M , RMX _M , LMX _H , and RMX _H in each band.

DESCRIPTION OF SYMBOLS 1,5,14 ... Addition part, 2,6 ... Subtraction part, 3, 4, 7, 8 ... Amplification part, 10 ... Acoustic characteristic control apparatus, 11 ... Band division part, 12 ... Signal generation part, 90 ... Electronic piano 91 ... Key, 92 ... Sound source, 93 ... Headphone, 94 ... Headphone unit.

Claims (5)

Band dividing means for dividing an input signal of two left and right channels into a plurality of bands, and outputting each of the divided signals of the left and right two channels belonging to each divided band;
The difference between the MID component signal, which is the sum of the left and right two-channel band-divided signals in the corresponding band, and the left and right two-channel band-divided signals in the corresponding band divided by the band dividing means SIDE component signal is generated, and the MID component signal and SIDE component signal of each band are mixed to generate a left and right two-channel component mixed signal for each band, and the left channel component mixed signal of each band is An acoustic characteristic control device comprising: signal generation means for outputting a right channel component mixed signal of each band to the headphone unit and to the right headphone unit of the headphone.   2. The signal generating unit according to claim 1, wherein the MID component signal and the SIDE component signal of each band are mixed at a mixing ratio for each band to generate a left and right two-channel component mixed signal for each band. The acoustic characteristic control device described. The band dividing means uses the left and right two-channel sound signals supplied from the electronic keyboard instrument as the left and right two-channel input signals, and the left and right two-channel sound signals are divided into three bands of low, middle, and high frequencies. And outputs a left and right two-channel band-divided signal in the low band, a right and left two-channel band-divided signal in the middle band, and a left and right two-channel band-divided signal in the high band,
The signal generating means is configured such that, for the middle band, the ratio of the MID component signal in the left and right two-channel component mixed signals in the band is higher than the ratio of the MID component signal in the low band and the high-frequency left and right two-channel component mixed signals. 3. The acoustic characteristic control device according to claim 1, wherein the MID component signal and the SIDE component signal in the band are mixed at a mixing ratio that also decreases.   The system further comprises an amplifying unit that amplifies the left and right channel component mixed signals of each band with a gain set for each, and outputs the amplified signals to the left headphone unit and the right headphone unit, respectively. The acoustic characteristic control device according to any one of claims 1 to 3. An electronic keyboard instrument that has a keyboard and outputs two left and right channel sound signals according to the operation of the keyboard;
The left and right two-channel input signals output from the electronic keyboard instrument are divided into a plurality of bands, and divided by the band dividing means for outputting the left and right two-channel band divided signals belonging to the divided bands, respectively. For the left and right two-channel band-divided signals in each band, the SIDE component signal that is the difference between the MID component signal that is the sum of the left and right two-channel band-divided signals in the band and the left and right two-channel band-divided signals in the band is Generate and mix the MID component signal and SIDE component signal of each band to generate a left and right channel component mixed signal for each band, and output the left channel component mixed signal of each band to the left headphone unit of the headphones. Acoustic characteristic control including signal generation means for outputting a right channel component mixed signal of each band to the right headphone unit of the headphone Electronic musical instrument, characterized in that it comprises a location.

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