JP6261998B2

JP6261998B2 - Acoustic signal processing device

Info

Publication number: JP6261998B2
Application number: JP2014017470A
Authority: JP
Inventors: 田口　豊; 豊田口
Original assignee: New Japan Radio Co Ltd
Current assignee: New Japan Radio Co Ltd
Priority date: 2014-01-31
Filing date: 2014-01-31
Publication date: 2018-01-17
Anticipated expiration: 2034-01-31
Also published as: JP2015144394A

Description

本発明はＬ信号とＲ信号の２チャンネルのステレオ音声信号を入力として、２つのスピーカにより再生されるステレオ音像を拡大する技術に係り、特にスピーカの放音方向を聴取者から見て横に向けた状態でも、クロストークキャンセル処理を加える事により、音像が２つのスピーカの外側に定位するようにした音響信号処理装置に関するものである。 The present invention relates to a technique for enlarging a stereo sound image reproduced by two speakers by inputting two-channel stereo audio signals of an L signal and an R signal, and in particular, directs the sound emission direction of the speakers sideways as viewed from the listener. The present invention also relates to an acoustic signal processing apparatus in which a sound image is localized outside two speakers by adding a crosstalk canceling process.

Ｌ音声信号とＲ音声信号の２チャンネルの音声信号を２つのスピーカで再生する際に、音場がより広くなるように再生する為に、クロストーク成分をキャンセルする手段を備える事がしばしば行われている。特許文献１のサラウンド再生回路は、Ｌ−Ｒの差信号を強調していたため、一方の耳に入る音響信号は、一方のスピーカから発せられた信号のみでなく、２つのスピーカから発せられた信号の加算結果となる。このため、耳における位相周波数特性に乱れが生じていたことから、広がり感はあるが、その定位が明確ではなくなるという問題があった。 When two-channel audio signals of L audio signal and R audio signal are reproduced by two speakers, a means for canceling the crosstalk component is often provided in order to reproduce the sound field to be wider. ing. Since the surround reproduction circuit of Patent Document 1 emphasizes the LR difference signal, the acoustic signal entering one ear is not only a signal emitted from one speaker but also a signal emitted from two speakers. The result of adding For this reason, since the phase frequency characteristic in the ear is disturbed, there is a problem that the localization is not clear although there is a sense of spread.

この間題を解決する為に、特許文献２の音響信号処理方法および装置では、クロストークキャンセル手段を備え、音像の定位を明確にし、位相周波数特性の乱れを小さくし、また図３に示すように左右のスピーカＳＰ（Ｌ），ＳＰ（Ｒ）の間隔が狭い場合でも、それらのスピーカＳＰ（Ｌ），ＳＰ（Ｒ）の外側に音像を生成する仮想スピーカＳＰ（ＤＬ）が明確に定位して知覚されるようになった。図３において、４０１はＬチャンネル音声出力、４０２はＲチャンネルクロストークキャンセル出力、４０３はＬチャンネルクロストーク成分、４０４はクロストークキャンセルイメージ、４０５は聴取者Ｍからみた仮想スピーカＳＰ（ＤＬ）の方向である。 In order to solve this problem, the acoustic signal processing method and apparatus of Patent Document 2 are provided with a crosstalk canceling means to clarify the localization of the sound image, to reduce the disturbance of the phase frequency characteristics, and as shown in FIG. Even when the distance between the left and right speakers SP (L) and SP (R) is narrow, the virtual speaker SP (DL) that generates a sound image outside the speakers SP (L) and SP (R) is clearly localized. It came to be perceived. In FIG. 3, 401 is an L channel audio output, 402 is an R channel crosstalk cancel output, 403 is an L channel crosstalk component, 404 is a crosstalk cancel image, and 405 is a virtual speaker SP (DL) direction as viewed from the listener M. It is.

特許第４３７１６２１号公報Japanese Patent No. 4371621 特許第４５０９６８６号公報Japanese Patent No. 4509686

しかしながら、特許文献２では、図４に示すように、左右のスピーカＳＰ（Ｌ），ＳＰ（Ｒ）の放音方向を、聴取者Ｍから見て横方向に向けた場合、９０度ずれた分の位相周波数特性の乱れによりクロストークキャンセル効果が減少してしまい、クロストーク成分のキャンセルが十分にできず、スピーカＳＰ（Ｌ）の外側に音像を生成する仮想スピーカＳＰ（ＤＬ）が明確に定位されなくなるという問題があった。また、音質も劣化し、特に、Ｌ信号とＲ信号の同位相の中低音域の音が中抜けするという問題もあった。 However, in Patent Document 2, as shown in FIG. 4, when the sound emission direction of the left and right speakers SP (L) and SP (R) is directed laterally as viewed from the listener M, the amount is shifted by 90 degrees. The cross-talk cancellation effect is reduced due to the disturbance of the phase frequency characteristics of the speaker, the cross-talk component cannot be sufficiently canceled, and the virtual speaker SP (DL) that generates the sound image outside the speaker SP (L) is clearly localized. There was a problem that it was not done. In addition, the sound quality deteriorates, and in particular, there is a problem that the sound in the middle and low frequencies in the same phase of the L signal and the R signal is lost.

本発明の目的は、音像の定位を明確にし、同位相の音の中抜けを少なくし、スピーカの放音方向を横方向に向けた場合でも、スピーカの外側に音像が明確に定位して知覚される様にした音響処理装置を提供することである。 The object of the present invention is to clarify the localization of the sound image, reduce the in-phase sound loss, and perceive the sound image clearly outside the speaker even when the sound emission direction of the speaker is directed horizontally. It is an object of the present invention to provide a sound processing apparatus that can be used.

上記目的を達成するために、請求項１にかかる発明は、Ｌチャンネル音声信号とＲチャンネル音声信号を入力してＬ側差信号強調信号とＲ側差信号強調信号を出力する差信号強調手段と、前記Ｌ側差信号強調信号よりＬチャンネルスピーカから右耳に伝わるクロストーク成分をキャンセルするとともに前記Ｒ側差信号強調信号よりＲチャンネルスピーカから左耳に伝わるクロストーク成分をキャンセルするクロストークキャンセル手段とを有する音響信号処理装置であって、前記差信号強調手段は、Ｌ側差信号強調手段とＲ側差信号強調手段とからなり、前記クロストークキャンセル手段は、Ｌ側クロストークキャンセル手段とＲ側クロストークキャンセル手段とからなり、前記Ｌ側差信号強調手段は、前記Ｒチャンネル音声信号を０．５以上１未満の増幅率で増幅した信号を前記Ｌチャンネル音声信号から減算したＬ側差信号と、前記Ｌチャンネル音声信号を０．５の増幅率で増幅した信号と前記Ｒチャンネル音声信号を０．５の増幅率で増幅した信号を加算して０を超え０．５以下の増幅率で増幅して得たセンタ信号とを加算し、該加算信号からカットオフ周波数が７ｋＨｚ以上１１ｋＨｚ以下の低域成分を取り出し、０を超え２．０以下の増幅率で増幅し、前記Ｌチャンネル音声信号に加算して、前記Ｌ側差信号強調信号として出力し、前記Ｒ側差信号強調手段は、前記Ｌチャンネル音声信号を０．５以上１未満の増幅率で増幅した信号を前記Ｒチャンネル音声信号から減算したＲ側差信号と、前記センタ信号とを加算し、該加算信号からカットオフ周波数が７ｋＨｚ以上１１ｋＨｚ以下の低域成分を取り出し、０を超え２．０以下の増幅率で増幅し、前記Ｒチャンネル音声信号に加算して、前記Ｒ側差信号強調信号として出力し、前記Ｌ側クロストークキャンセル手段は、前記Ｒ側差信号強調信号を入力し、１ｍｓ以下（但し、０ではない）の第１の遅延をさせ、カットオフ周波数が１ｋＨｚ以上１１ｋＨｚ以下の低域成分を取り出して、０を越え０．５以下の増幅率で増幅した信号を前記Ｒ側差信号強調信号に加算する第１のフィードバック処理を行い、前記第１の遅延をさせた信号から周波数が１００Ｈｚ以上３００Ｈｚ以下の低音域を取り除き、０を越え０．７以下の増幅率で増幅して得られた信号をＬ側クロストークキャンセル信号として生成して、これを前記Ｌ側差信号強調信号から減算した信号をＬ側チャンネル音声出力信号とし、前記Ｒ側クロストークキャンセル手段は、前記Ｌ側差信号強調信号を入力し、１ｍｓ以下（但し、０ではない）の第２の遅延をさせ、カットオフ周波数が１ｋＨｚ以上１１ｋＨｚ以下の低域成分を取り出して、０を越え０．５以下の増幅率で増幅した信号を前記Ｌ側差信号強調信号に加算する第２のフィードバック処理を行い、前記第２の遅延をさせた信号から周波数が１００Ｈｚ以上３００Ｈｚ以下の低音域を取り除き、０を越え０．７以下の増幅率で増幅して得られた信号をＲ側クロストークキャンセル信号として生成して、これを前記Ｒ側差信号強調信号から減算した信号をＲ側チャンネル音声出力信号とする、ことを特徴とする。
In order to achieve the above object, the invention according to claim 1 includes difference signal enhancement means for inputting an L channel audio signal and an R channel audio signal and outputting an L side difference signal enhancement signal and an R side difference signal enhancement signal. Crosstalk canceling means for canceling the crosstalk component transmitted from the L channel speaker to the right ear from the L side difference signal enhancement signal and canceling the crosstalk component transmitted from the R channel difference signal enhancement signal to the left ear from the R side difference signal enhancement signal The difference signal enhancement means comprises an L side difference signal enhancement means and an R side difference signal enhancement means, and the crosstalk cancellation means comprises an L side crosstalk cancellation means and an R side difference signal enhancement means. It consists of a side crosstalk canceling means, wherein the L-side difference signal enhancement means 0.5 than the R-channel audio signal L-side difference signal and the amplified signal was subtracted from the L channel audio signal with an amplification factor of less than 1 and, amplified signal by the amplification factor of the L channel audio signal of 0.5 and the R channel audio signal 0.5 And a center signal obtained by amplifying the signal with an amplification factor of more than 0 and less than or equal to 0.5, and adding the signal amplified at an amplification factor of 5 to a low frequency component having a cutoff frequency of 7 kHz to 11 kHz was removed, was amplified by 2.0 or less gain than 0, by adding the L channel audio signal, and outputs as the L-side difference signal enhancement signal, the R-side difference signal enhancement means, said L channels and R-side difference signal and the amplified signal an audio signal with an amplification factor of less than 1 0.5 or more was subtracted from the R channel audio signal, the adding and the center signal, the cut-off frequency from the sum signal is more than 7 kHz 1 kHz removed following low-frequency component is amplified by 2.0 or less gain than 0, it adds to the R-channel audio signal, and outputs as the R-side difference signal enhancement signal, the L-side crosstalk cancellation The means inputs the R side difference signal emphasizing signal, delays the first delay of 1 ms or less (but not 0), extracts a low frequency component having a cutoff frequency of 1 kHz or more and 11 kHz or less, and exceeds 0 A first feedback process for adding a signal amplified with an amplification factor of 0.5 or less to the R side difference signal emphasizing signal is performed, and a low frequency range of 100 Hz to 300 Hz is obtained from the first delayed signal. A signal obtained by removing and amplifying with an amplification factor of greater than 0 and less than 0.7 is generated as an L-side crosstalk cancellation signal, and a signal obtained by subtracting the signal from the L-side difference signal enhancement signal is L-side The R side crosstalk canceling means inputs the L side difference signal emphasizing signal as a channel audio output signal, delays the second delay of 1 ms or less (but not 0), and the cut-off frequency is 1 kHz or more and 11 kHz. The following low-frequency component is extracted, and a second feedback process is performed to add a signal amplified with an amplification factor of more than 0 and less than 0.5 to the L-side difference signal enhancement signal, and the second delay is performed. A signal obtained by removing a low frequency range from 100 Hz to 300 Hz from the signal and amplifying the signal with an amplification factor exceeding 0 and not more than 0.7 is generated as an R side crosstalk cancellation signal, which is obtained as the R side difference. A signal subtracted from the signal enhancement signal is used as an R-side channel audio output signal.

請求項２にかかる発明は、請求項１に記載の音響信号処理装置において、さらに、Ｌ側中低音域強調手段とＲ側中低音域強調手段からなる中低音域強調手段を備え、前記Ｌ側中低音域強調手段は、前記Ｌ側差信号強調信号を入力し、１ｍｓ以下（但し、０ではない）の第３の遅延とそれに続く１ｍｓ以下（但し、０ではない）の第４の遅延を行ってから、０を超え０．５以下の増幅率で増幅した信号を前記Ｌ側差信号強調信号に加算する第３のフィードバック処理を行い、前記第３の遅延をした信号から周波数が８００Ｈｚ以上の高音域を取り除き、０を超え０．５以下の増幅率で増幅し、再生スピーカの最低共振周波数以上の高音域を取り出してＬ側中低音域強調信号として、前記Ｌ側チャンネル音声出力信号に加算し、前記Ｒ側中低音域強調手段は、前記Ｒ側差信号強調信号を入力し、１ｍｓ以下（但し、０ではない）の第５の遅延とそれに続く１ｍｓ以下（但し、０ではない）の第６の遅延を行ってから、０を超え０．５以下の増幅率で増幅した信号を前記Ｒ側差信号強調信号に加算する第４のフィードバック処理を行い、前記第５の遅延をした信号から周波数が８００Ｈｚ以上の高音域を取り除き、０を超え０．５以下の増幅率で増幅し、再生スピーカの最低共振周波数以上の高音域を取り出してＲ側中低音域強調信号として、前記Ｒ側チャンネル音声出力信号に加算する、ことを特徴とする。
According to a second aspect of the present invention, in the acoustic signal processing device according to the first aspect of the present invention, the acoustic signal processing device further includes a middle / low range emphasizing unit including an L side middle / low range emphasizing unit and an R side middle / low range emphasizing unit. The mid-low range emphasis means inputs the L side difference signal emphasizing signal, and has a third delay of 1 ms or less (but not 0) and a subsequent 4 ms delay of 1 ms or less (but not 0). And then performing a third feedback process for adding a signal amplified with an amplification factor of greater than 0 and less than or equal to 0.5 to the L-side difference signal enhancement signal, and the frequency of the third delayed signal is 800 Hz or more. Is amplified with an amplification factor of more than 0 and less than 0.5, and a high frequency range above the lowest resonance frequency of the reproduction speaker is taken out and used as an L side mid / low range emphasis signal to the L side channel audio output signal. Add, the R side middle bass The adjusting means inputs the R-side difference signal emphasizing signal, performs a fifth delay of 1 ms or less (but not 0), and then a sixth delay of 1 ms or less (but not 0). , A fourth feedback process is performed in which a signal amplified with an amplification factor of more than 0 and less than or equal to 0.5 is added to the R-side difference signal emphasizing signal, and a high frequency range having a frequency of 800 Hz or more is obtained from the fifth delayed signal. And amplifying with an amplification factor of more than 0 and 0.5 or less, and taking out a high frequency range above the lowest resonance frequency of the reproduction speaker and adding it to the R side channel audio output signal as an R side middle / low frequency range emphasis signal, It is characterized by that.

請求項１にかかる発明では、差信号強調手段によって、Ｌ側差信号強調信号とＲ側差信号強調信号をそれぞれ独立して生成するので、音像の定位を明確にする事ができる。また、クロストークキャンセル手段によって、Ｒ側差信号強調信号に第１の遅延をかけて第１のフィードバック処理により残響を付加し、高域と低域を除去した信号をＬ差信号強調信号から減算するので、Ｒチャンネルスピーカからのクロストーク成分がＬチャンネルスピーカによってキャンセルされる。また、Ｌ側差信号強調信号に第２の遅延をかけて第２のフィードバック処理により残響を付加し、高域と低域を除去した信号をＲ側差信号好調信号から減算するので、Ｌチャンネルスピーカからのクロストーク成分がＲチャンネルスピーカによってキャンセルされる。これらにより、位相周波数特性の乱れを低減でき、また音像を、２つのスピーカの外側に明確に定位するように知覚させることができ、特に、聴取者から見てスピーカの放音方向を横方向に向けた場合に有効である。 In the invention according to claim 1, since the L-side difference signal enhancement signal and the R-side difference signal enhancement signal are generated independently by the difference signal enhancement means, the localization of the sound image can be clarified. Further, the crosstalk canceling means adds a reverberation by the first feedback processing with a first delay to the R side difference signal enhancement signal, and subtracts the signal from which the high frequency and the low frequency are removed from the L difference signal enhancement signal. Therefore, the crosstalk component from the R channel speaker is canceled by the L channel speaker. Further, since the reverberation is added by the second feedback processing by applying the second delay to the L side difference signal emphasizing signal, and the signal from which the high frequency and the low frequency are removed is subtracted from the R side difference signal strong signal, the L channel The crosstalk component from the speaker is canceled by the R channel speaker. As a result, the disturbance of the phase frequency characteristics can be reduced, and the sound image can be perceived to be clearly located outside the two speakers. In particular, the sound emission direction of the speakers is set laterally as viewed from the listener. Effective when directed.

請求項２にかかる発明では、中低音域強調手段によって、Ｌチャンネル音声信号出力にＬ側中低音域強調信号が加算され、Ｒチャンネル音声信号出力にＲ側中低音域強調信号が加算されるので、聴取者から見てスピーカの放音方向を横に向けた事で同位相出力信号が１８０度ずれてしまう事による音の中抜けを補正する事ができる。 In the invention according to claim 2, since the L-side mid / low range emphasis signal is added to the L channel audio signal output and the R side mid / low range emphasis signal is added to the R channel audio signal output by the mid / low range emphasis means. When the sound output direction of the speaker is turned sideways as viewed from the listener, it is possible to correct the sound omission due to the in-phase output signal being shifted by 180 degrees.

本発明の第１の実施例の音響信号処理装置の構成を示すブロック図である。It is a block diagram which shows the structure of the acoustic signal processing apparatus of 1st Example of this invention. 本発明の第２の実施例の音響信号処理装置の構成を示すブロック図である。It is a block diagram which shows the structure of the acoustic signal processing apparatus of 2nd Example of this invention. 従来のクロストークキャンセル信号処理装置における仮想スピーカの位置を示した説明図である。It is explanatory drawing which showed the position of the virtual speaker in the conventional crosstalk cancellation signal processing apparatus. 本発明の音響信号処理装置における仮想スピーカの位置を示した説明図である。It is explanatory drawing which showed the position of the virtual speaker in the acoustic signal processing apparatus of this invention. 左右のスピーカ間隔が聴取者の両耳の距離よりも短い場合を示した説明図である。It is explanatory drawing which showed the case where the space | interval of a speaker on either side is shorter than the distance of a listener's both ears. 左右のスピーカ間隔が聴取者の両耳の距離よりも長い場合を示した説明図である。It is explanatory drawing which showed the case where the space | interval of a speaker on either side is longer than the distance of a listener's both ears. 聴取者から見てスピーカの放音方向を横方向に向けた場合の音の進行方向を示した説明図である。It is explanatory drawing which showed the advancing direction of the sound at the time of directing the sound emission direction of a speaker to a horizontal direction seeing from a listener.

図５に示すように、左右のスピーカＳＰ（Ｌ），ＳＰ（Ｒ）の放音方向が聴取者Ｍを向いている場合には、聴取者Ｍの左耳ＥＬと右耳ＥＲの間の距離をａ（ｍ）とし、ＬチャンネルスピーカＳＰ（Ｌ）と左耳ＥＲの間の距離をｂ（ｍ）とし、ＲチャンネルスピーカＳＰ（Ｒ）と右耳ＥＲの間の距離をｃ（ｍ）とし、スピーカＳＰ（Ｌ），ＳＰ（Ｒ）と聴取者Ｍの間の距離をｈ（ｍ）としたとき、聴取者Ｍの右耳ＥＲに届くＬチャンネルスピーカＳＰ（Ｌ）からのクロストーク成分４０３（図３）を、ＲチャンネルスピーカＳＰ（Ｒ）でキャンセルする為の、Ｒチャンネルクロストークキャンセル出力４０２（図３）の遅延時間Ｄ１（ｓ）は、

に設定すればよい。Ｖは音速（ｍ／ｓ）であり、

である。ｔは摂氏温度（℃）である。 As shown in FIG. 5, when the sound emission directions of the left and right speakers SP (L) and SP (R) are directed to the listener M, the distance between the left ear EL and the right ear ER of the listener M. Is a (m), the distance between the L channel speaker SP (L) and the left ear ER is b (m), and the distance between the R channel speaker SP (R) and the right ear ER is c (m). When the distance between the speakers SP (L), SP (R) and the listener M is h (m), the crosstalk component 403 from the L channel speaker SP (L) reaching the right ear ER of the listener M The delay time D1 (s) of the R channel crosstalk cancel output 402 (FIG. 3) for canceling (FIG. 3) by the R channel speaker SP (R) is:

Should be set. V is the speed of sound (m / s)

It is. t is the Celsius temperature (° C.).

また、図６に示すように、スピーカＳＰ（Ｌ），ＳＰ（Ｒ）が離れていて、聴取者Ｍの両耳ＥＬ，ＥＲの外側にある場合の、Ｒチャンネルクロストークキャンセル出力４０２（図３）の遅延時間Ｄ２（ｓ）は、

に設定すればよい。 Also, as shown in FIG. 6, the R channel crosstalk cancellation output 402 (FIG. 3) when the speakers SP (L) and SP (R) are separated and outside the binaural ears EL and ER of the listener M. ) Delay time D2 (s)

Should be set.

しかし、図７のように、スピーカＳＰ（Ｌ），ＳＰ（Ｒ）の放音方向が聴取者Ｍから見て横方向を向いている場合の音は、スピーカＳＰ（Ｌ），ＳＰ（Ｒ）の指向性により、聴取者Ｍから見て横に向かって進んでいく。また、室内であれば壁からの反射音の影響もあり、結果的に聴取者Ｍは、放音方向が正面に向けられた場合のスピーカから放音される音よりも、位相周波数特性が乱れた音を聞くことになる。 However, as shown in FIG. 7, when the sound emission direction of the speakers SP (L) and SP (R) is in the horizontal direction when viewed from the listener M, the sounds SP (L) and SP (R) Due to the directivity, the sound proceeds from the listener M toward the side. In addition, if it is indoors, there is also an influence of reflected sound from the wall. As a result, the listener M has a more disturbed phase frequency characteristic than the sound emitted from the speaker when the sound emission direction is directed to the front. You will hear the sound.

そこで、本発明では、スピーカの放音方向を横方向に向けた場合に起きるクロストークキャンセル効果の減少を防ぐ為に、Ｌ側差信号（Ｌ−Ｒ）にセンタ信号を加算した信号から取り出した７〜１１ｋＨｚの低域信号に、元のＬ信号を加算してＬ側差信号強調信号を生成する。また、Ｒ側差信号（Ｒ−Ｌ）にセンタ信号を加算した信号から取り出した７〜１１ｋＨｚの低域信号に、元のＲ信号を加算してＲ側差信号強調信号を生成する。 Therefore, in the present invention, in order to prevent a reduction in the crosstalk cancellation effect that occurs when the sound emission direction of the speaker is directed to the lateral direction, the signal is extracted from the signal obtained by adding the center signal to the L side difference signal (LR). The original L signal is added to the low frequency signal of 7 to 11 kHz to generate an L side difference signal enhancement signal. Further, the R side difference signal enhancement signal is generated by adding the original R signal to the 7 to 11 kHz low-frequency signal extracted from the signal obtained by adding the center signal to the R side difference signal (RL).

また、本発明では、Ｒ側差信号強調信号に第１の遅延を施しさらに低域信号を取り出した信号をＲ側差信号強調信号に加算する第１のフィードバック処理と、Ｌ側差信号強調信号に第２の遅延を施し低域信号を取り出した信号をＬ側差信号強調信号に加算する第２のフィードバック処理を用いて、クロストークキャンセル信号に残響効果を付加し、位相周波数特性が乱れたクロストーク成分をキャンセルする。 In the present invention, a first feedback process for adding a signal obtained by applying a first delay to the R-side difference signal enhancement signal and extracting a low-frequency signal to the R-side difference signal enhancement signal, and an L-side difference signal enhancement signal The reverberation effect was added to the crosstalk cancellation signal, and the phase frequency characteristic was disturbed by using the second feedback processing that adds the signal obtained by applying the second delay to the low-frequency signal to the L-side difference signal enhancement signal. Cancel the crosstalk component.

さらに、本発明では、Ｌ側差信号強調信号に第３と第４の遅延を付加してＬ側差信号強調信号に加算する第３のフィードバック処理の出力から、Ｌ側中低音域強調信号を生成してＬチャンネル音声出力信号に加算し、また、Ｒ側差信号強調信号に第５と第６の遅延を付加してＲ側差信号強調信号に加算する第４のフィードバック処理の出力から、Ｒ側中低音域強調信号を生成してＲチャンネル音声出力信号に加算する。これにより、図７に示すようにスピーカの放音方向を横に向けたことで同位相出力信号が１８０度ずれてしまう事による音の中抜けを、Ｌ側中低音域強調信号、Ｒ側中低音域強調信号で補正する。中低音域強調信号を生成するための第３、第４のフィードバック処理での遅延量は、クロストークキャンセル信号を生成するための第１、第２のフィードバック処理での遅延量に対して、若干ずらした値が望ましい。これによって、クロストークキャンセル信号との相関による打消し合いを減少させる事ができる。 Further, according to the present invention, the L-side middle / low range emphasis signal is obtained from the output of the third feedback processing that adds the third and fourth delays to the L-side difference signal emphasis signal and adds to the L-side difference signal emphasis signal. From the output of the fourth feedback processing that is generated and added to the L-channel audio output signal, and added to the R-side difference signal enhancement signal by adding the fifth and sixth delays to the R-side difference signal enhancement signal, An R-side mid / low range emphasis signal is generated and added to the R channel audio output signal. As a result, as shown in FIG. 7, the sound output from the in-phase output signal is shifted by 180 degrees by turning the sound output direction of the speaker sideways. Correct with low range emphasis signal. The amount of delay in the third and fourth feedback processing for generating the mid-low range emphasis signal is slightly smaller than the amount of delay in the first and second feedback processing for generating the crosstalk cancellation signal. A shifted value is desirable. As a result, cancellation due to correlation with the crosstalk cancellation signal can be reduced.

＜第１の実施例＞
図１に本発明の第１の実施例の音響信号処理装置の構成を示す。１００は差信号強調手段、２００はクロストークキャンセル手段である。 <First embodiment>
FIG. 1 shows the configuration of an acoustic signal processing apparatus according to the first embodiment of the present invention. Reference numeral 100 denotes difference signal emphasizing means, and reference numeral 200 denotes crosstalk canceling means.

差信号強調手段１００において、１０１はＬチャンネル音声信号入力端子、１０２はＲチャンネル音声信号入力端子、１０３、１０４は増幅率が０．５以上１．０未満の乗算器、１０５、１０６は減算器、１０７、１０８は増幅率が０．５の乗算器、１０９、１１１、１１２、１１７、１１８は加算器、１１０は増幅率が０〜０．５の乗算器、１１３、１１４はカットオフ周波数が７〜１１ｋＨｚのローパスフィルタ、１１５、１１６は増幅率が０〜２．０の乗算器である。 In the difference signal emphasizing means 100, 101 is an L channel audio signal input terminal, 102 is an R channel audio signal input terminal, 103 and 104 are multipliers having an amplification factor of 0.5 or more and less than 1.0, and 105 and 106 are subtractors. 107, 108 are multipliers with an amplification factor of 0.5, 109, 111, 112, 117, 118 are adders, 110 is a multiplier with an amplification factor of 0 to 0.5, and 113, 114 are cutoff frequencies. 7 to 11 kHz low-pass filters 115 and 116 are multipliers having an amplification factor of 0 to 2.0.

クロストークキャンセル手段２００において、２０１、２０２は加算器、２０３、２０４は遅延時間が１ｍｓ以下（ただし０ではない）の遅延器、２０５、２０６はカットオフ周波数が１〜１１ｋＨｚのローパスフィルタ、２０７、２０８は増幅率が０〜０．５の乗算器、２０９、２１０はカットオフ周波数が１００Ｈｚ〜３００Ｈｚのハイパスフィルタ、２１１、２１２は増幅率が０〜０．７の乗算器、２１３、２１４は減算器、２１５はＬチャンネル音声信号出力端子、２１６はＲチャンネル音声信号出力端子である。 In the crosstalk canceling means 200, 201 and 202 are adders, 203 and 204 are delay devices having a delay time of 1 ms or less (but not 0), 205 and 206 are low-pass filters having a cutoff frequency of 1 to 11 kHz, 207, 208 is a multiplier with an amplification factor of 0 to 0.5, 209 and 210 are high-pass filters with a cutoff frequency of 100 Hz to 300 Hz, 211 and 212 are multipliers with an amplification factor of 0 to 0.7, and 213 and 214 are subtractions. 215 is an L channel audio signal output terminal, and 216 is an R channel audio signal output terminal.

次に第１の実施例の動作について説明する。Ｌチャンネル音声信号入力端子１０１への入力信号は、乗算器１０３、減算器１０５に入力し、Ｒチャンネル音声信号入力端子１０２への信号は乗算器１０４、減算器１０６に入力し、それぞれチャンネルごとのレベルが調整される。乗算器１０３の出力は減算器１０６の入力になってＲチャンネル音声信号から減算され、減算器１０６からＲ側差信号（Ｒ−Ｌ）が出力する。乗算器１０４の出力は減算器１０５の入力になってＬチャンネル音声信号から減算され、減算器１０５からＬ側差信号（Ｌ−Ｒ）が出力する。そして、それら差信号はそれぞれ加算器１１１、１１２の入力になる。 Next, the operation of the first embodiment will be described. An input signal to the L channel audio signal input terminal 101 is input to the multiplier 103 and the subtractor 105, and a signal to the R channel audio signal input terminal 102 is input to the multiplier 104 and the subtractor 106, respectively. The level is adjusted. The output of the multiplier 103 is input to the subtractor 106 and is subtracted from the R channel audio signal, and the R side difference signal (RL) is output from the subtractor 106. The output of the multiplier 104 becomes an input of the subtractor 105 and is subtracted from the L channel audio signal, and the L side difference signal (LR) is output from the subtractor 105. These difference signals are input to adders 111 and 112, respectively.

また、Ｌチャンネル音声信号入力端子１０１への入力信号は乗算器１０７に入力し、Ｒチャンネル音声信号入力端子１０２への入力信号は乗算器１０８に入力し、それぞれチャンネルごとのレベルが調整され、加算器１０９で加算され、その加算信号は乗算器１１０の入力になる。乗算器１１０はセンタ信号のボリュームとして働き、出力するセンタ信号は加算器１１１、１１２の入力になる。よって、加算器１１１からはＬ側差信号にセンタ信号が加算された信号が出力し、加算器１１２からはＲ側差信号にセンタ信号が加算された信号が出力する。 Also, the input signal to the L channel audio signal input terminal 101 is input to the multiplier 107, the input signal to the R channel audio signal input terminal 102 is input to the multiplier 108, and the level for each channel is adjusted and added. The signal is added by the multiplier 109, and the added signal becomes an input of the multiplier 110. The multiplier 110 functions as a volume of the center signal, and the center signal to be output becomes the input of the adders 111 and 112. Therefore, the adder 111 outputs a signal obtained by adding the center signal to the L-side difference signal, and the adder 112 outputs a signal obtained by adding the center signal to the R-side difference signal.

加算器１１１、１１２の出力はローパスフィルタ１１３、１１４の入力になり、低い周波数成分に分離される。ローパスフィルタ１１３、１１４の出力は乗算器１１５，１１６の入力になりその乗算器１１５，１１６の出力は加算器１１７、１１８の入力なる。加算器１１７にはＬチャンネル音声信号入力端子１０１への入力信号が入力しているので、加算器１１７からはＬ側差信号（Ｌ−Ｒ）を強調したＬ側差信号強調信号が出力する。加算器１１８にはＲチャンネル音声信号入力端子１０２への入力信号が入力しているので、加算器１１８からはＲ側差信号（Ｒ−Ｌ）を強調したＲ側差信号強調信号が出力する。このとき、乗算器１１５はＬ側差信号強調信号のボリュームとして働き、乗算器１１６はＲ側差信号強調信号のボリュームとして働く。 The outputs of the adders 111 and 112 are input to the low-pass filters 113 and 114, and are separated into low frequency components. The outputs of the low-pass filters 113 and 114 are input to the multipliers 115 and 116, and the outputs of the multipliers 115 and 116 are input to the adders 117 and 118. Since the adder 117 receives an input signal to the L channel audio signal input terminal 101, the adder 117 outputs an L side difference signal enhancement signal in which the L side difference signal (LR) is emphasized. Since the adder 118 receives an input signal to the R channel audio signal input terminal 102, the adder 118 outputs an R side difference signal enhancement signal in which the R side difference signal (RL) is emphasized. At this time, the multiplier 115 functions as a volume of the L-side difference signal enhancement signal, and the multiplier 116 functions as a volume of the R-side difference signal enhancement signal.

また、加算器１１７、１１８の出力は、加算器２０１、２０２、減算器２１３、２１４の入力になる。加算器２０１、２０２の出力は、遅延器２０３、２０４で第１、第２の遅延を付加され、その出力はローパスフィルタ２０５、２０６、ハイパスフィルタ２０９、２１０の入力になり、それぞれ低い周波数成分と高い周波数成分に分離される。ローパスフィルタ２０５、２０６の出力は、乗算器２０７、２０８の入力になり、この乗算器２０７、２０８はフィードバック信号用のボリュームとして機能し、その出力は加算器２０１、２０２で加算され、ここで第１、第２のフィードバック処理が行われ、その結果がハイパスフィルタ２０９、２１０に入力する。ハイパスフィルタ２０９、２１０の出力は乗算器２１１、２１２の入力になる。この乗算器２１１、２１２はクロストークキャンセル信号用のボリュームとして機能し、その出力は減算器２１３、２１４の入力になり、この減算器２１３、２１４から、それぞれＬチャンネル音声信号出力端子２１５、Ｒチャンネル音声信号出力端子２１６に出力する。
The outputs of the adders 117 and 118 are input to the adders 201 and 202 and the subtracters 213 and 214, respectively. The outputs of the adders 201 and 202 are added with the first and second delays by the delay units 203 and 204, and the outputs are input to the low-pass filters 205 and 206 and the high-pass filters 209 and 210, respectively. Separated into high frequency components. The outputs of the low-pass filters 205 and 206 become inputs to the multipliers 207 and 208. The multipliers 207 and 208 function as a feedback signal volume, and the outputs are added by the adders 201 and 202. First and second feedback processing is performed, and the result is input to the high-pass filters 209 and 210. The outputs of the high pass filters 209 and 210 are the inputs of the multipliers 211 and 212. The multipliers 211 and 212 function as a volume for a crosstalk cancellation signal, and outputs thereof are input to subtracters 213 and 214. The subtracters 213 and 214 respectively output an L channel audio signal output terminal 215 and an R channel. Output to the audio signal output terminal 216 .

このように、第１の実施例によれば、差信号強調手段１００において、Ｌ側差信号（Ｌ−Ｒ）を強調したＬ側差信号強調信号とＲ側差信号（Ｒ−Ｌ）を強調したＲ側差信号強調信号をそれぞれ独立して生成するので、２つのスピーカの放射方向を横方向に向けた場合でも、図４に示すように、音像の定位を明確にする事ができる。 As described above, according to the first embodiment, the difference signal emphasizing unit 100 emphasizes the L side difference signal enhancement signal and the R side difference signal (R−L) in which the L side difference signal (L−R) is enhanced. Since the R side difference signal emphasizing signal is generated independently, the localization of the sound image can be clarified as shown in FIG. 4 even when the radiation directions of the two speakers are oriented in the horizontal direction.

また、クロストークキャンセル手段２００において、Ｒ側差信号強調信号に第１の遅延をかけ、更に、第１のフィードバック処理により残響を付加し、ローパスフィルタ２０５とハイパスフィルタ２０９で高域と低域を除去した信号を、減算器２１３でＬ差信号強調信号から減算するので、Ｒチャンネルスピーカからのクロストーク成分がＬチャンネルスピーカによってキャンセルされる。 Further, in the crosstalk cancellation means 200, a first delay is applied to the R-side difference signal emphasis signal, and reverberation is added by the first feedback processing. The low-pass filter 205 and the high-pass filter 209 reduce the high frequency and low frequency. Since the removed signal is subtracted from the L difference signal enhancement signal by the subtractor 213, the crosstalk component from the R channel speaker is canceled by the L channel speaker.

また、Ｌ側差信号強調信号に第２の遅延をかけ、更に、第２のフィードバック処理により残響を付加し、ローパスフィルタ２０６とハイパスフィルタ２１０で高域と低域を除去した信号を、減算器２１４でＲ側差信号強調信号から減算するので、Ｌチャンネルスピーカからのクロストーク成分がＲチャンネルスピーカによってキャンセルされる。 Also, a signal obtained by applying a second delay to the L-side difference signal enhancement signal, adding reverberation by the second feedback processing, and removing the high frequency and low frequency by the low pass filter 206 and the high pass filter 210 is subtracted. Since the subtracted signal is subtracted from the R side difference signal emphasizing signal in 214, the crosstalk component from the L channel speaker is canceled by the R channel speaker.

これらにより、位相周波数特性の乱れを低減でき、また音像を、２つのスピーカの外側に明確に定位するように知覚させることができる。特に、聴取者から見てスピーカの放音方向を横方向に向けた場合に有効である。 As a result, the disturbance of the phase frequency characteristic can be reduced, and the sound image can be perceived to be clearly localized outside the two speakers. This is particularly effective when the sound output direction of the speaker is directed laterally as viewed from the listener.

＜第２の実施例＞
図２に本発明の第２の実施例の音響信号処理装置の構成を示す。図１の音響信号処理装置は、差信号強調手段１００とクロストークキャンセル手段２００により構成されるものであったが、本実施例では、これらにさらに中低音域強調手段３００を備える。 <Second embodiment>
FIG. 2 shows the configuration of an acoustic signal processing apparatus according to the second embodiment of the present invention. The acoustic signal processing apparatus of FIG. 1 is configured by the difference signal emphasizing unit 100 and the crosstalk canceling unit 200. In the present embodiment, these are further provided with a mid-low range emphasizing unit 300.

中低音域強調手段３００において、３０１、３０２、３１５、３１６は加算器、３０３、３０４、３０５、３０６は遅延器、３０７、３０８、３１１、３１２は増幅率が０〜０．５の乗算器、３０９、３１０は８００Ｈｚ以上の高音を取り除くローパスフィルタ、３１３、３１４は再生するスピーカの最低共振周波数ｆ０（４００Ｈｚ以下）をカットオフ周波数としたハイパスフィルタである。 In the mid-low range emphasis means 300, 301, 302, 315 and 316 are adders, 303, 304, 305 and 306 are delay units, 307, 308, 311 and 312 are multipliers having an amplification factor of 0 to 0.5, Reference numerals 309 and 310 denote low-pass filters that remove high frequencies of 800 Hz or higher, and reference numerals 313 and 314 denote high-pass filters that use the lowest resonance frequency f0 (400 Hz or lower) of the speaker to be reproduced as a cutoff frequency.

次に第２の実施例の動作について説明する。差信号強調手段１００の加算器１１７、１１８から出力するＬ側差信号強調信号、Ｒ側差信号強調信号は、加算器３０１、３０２の入力になる。その加算器３０１、３０２の出力は遅延器３０３、３０４の入力になり、第３、第５の遅延が付加され、その出力はローパスフィルタ３０９、３１０の入力になるとともに、遅延器３０５、３０６の入力になる。遅延器３０５、３０６では第４、第６の遅延が付加され、その出力は乗算器３０７、３０８の入力になる。乗算器３０７、３０８はフィードバック信号用のボリュームとして機能し、その出力は加算器３０１、３０２の入力になり、Ｒ差信号強調信号、Ｌ差信号強調信号と加算され、そこで第３、第４のフィードバック処理が行われる。 Next, the operation of the second embodiment will be described. The L-side difference signal enhancement signal and the R-side difference signal enhancement signal output from the adders 117 and 118 of the difference signal enhancement means 100 are input to the adders 301 and 302, respectively. The outputs of the adders 301 and 302 become the inputs of the delay units 303 and 304, and the third and fifth delays are added. The outputs of the adders 301 and 302 become the inputs of the low-pass filters 309 and 310. It becomes input. Fourth delay devices 305, 306 the delay of the sixth is added, the output is the input of the multiplier 307 and 308. The multipliers 307 and 308 function as a feedback signal volume, and the outputs thereof are input to the adders 301 and 302, which are added to the R difference signal enhancement signal and the L difference signal enhancement signal. Feedback processing is performed.

遅延器３０３、３０４の出力は、ローパスフィルタ３０９、３１０で低い周波数成分に分離され、乗算器３１１、３１２の入力になる。乗算器３１１、３１２は中低音域強調信号用ボリュームとして機能し、その出力はハイパスフィルタ３１３、３１４の入力になり、高い周波数成分に分離される。 The outputs of the delay units 303 and 304 are separated into low frequency components by the low-pass filters 309 and 310 and input to the multipliers 311 and 312. The multipliers 311 and 312 function as a volume for the mid-low range emphasis signal, and the output is input to the high-pass filters 313 and 314 and separated into high frequency components.

ハイパスフィルタ３１３、３１４からは、ｆ０〜８００Ｈｚの間のＬ側中低音域強調信号、Ｒ側中低音域強調信号が出力し、加算器３１５、３１６において、それぞれ加算器２１３、２１４の出力と加算され、Ｌチャネル音声信号出力端子２１５、Ｒチャネル音声信号出力端子２１６に出力する。 From the high-pass filters 313 and 314, an L-side mid-low range emphasis signal and an R-side mid-low range emphasis signal between f0 and 800 Hz are output, and the adders 315 and 316 add the outputs of the adders 213 and 214, respectively. And output to the L channel audio signal output terminal 215 and the R channel audio signal output terminal 216.

このように、第２の実施例によれば、中低音域強調手段３００によって、Ｌチャンネル音声出力信号にＬ中低音域強調信号（ｆ０〜８００Ｈｚ）が加算され、Ｒチャンネル音声出力信号にＲ中低音域強調信号（ｆ０〜８００Ｈｚ）が加算されるので、聴取者から見てスピーカの放音方向を横に向けた事で同位相出力信号が１８０度ずれてしまう事による音の中抜けを補正する事ができる。 As described above, according to the second embodiment, the mid-low range emphasis unit 300 adds the L mid-low range emphasis signal (f0 to 800 Hz) to the L-channel audio output signal, and the R-channel audio output signal includes the mid-R range. Low range emphasis signal (f0-800Hz) is added, so correcting the sound omission due to the in-phase output signal being shifted 180 degrees by turning the speaker's sound emission sideways as seen from the listener I can do it.

１００：差信号強調手段
１０１：Ｌチャンネル音声信号入力端子
１０２：Ｒチャンネル音声信号入力端子
１０３，１０４，１０７，１０８，１１０，１１５，１１６：乗算器
１０５，１０６：減算器
１０９，１１１，１１２，１１７，１１８：加算器

２００：クロストークキャンセル手段
２０１，２０２：加算器
２０３，２０４：遅延器
２０５，２０６：ローパスフィルタ
２０７，２０８，２１１，２１２：乗算器
２０９，２１０：ハイパスフィルタ
２１３，２１４：減算器
２１５：Ｌチャンネル音声信号出力端子
２１６：Ｒチャンネル音声信号出力端子

３００：中低音域強調手段
３０１，３０２，３１５，３１６：加算器
３０３，３０４，３０５，３０６：遅延器
３０７，３０８，３１１，３１２：乗算器
３０９，３１０：ローパスフィルタ
３１３，３１４：ハイパスフィルタ

４０１：Ｌチャンネル音声出力
４０２：Ｒチャンネルクロストークキャンセル出力
４０３：Ｌチャンネルクロストーク成分
４０４：クロストークキャンセルイメージ
４０５：聴取者Ｍからみた仮想スピーカＳＰ（ＤＬ）の方向

ＳＰ（Ｌ）：Ｌチャンネルスピーカ
ＳＰ（Ｒ）：Ｒチャンネルスピーカ
ＳＰ（ＤＬ）：Ｌチャンネル仮想スピーカ
Ｍ：聴取者
ＥＬ：左耳
ＥＲ：右耳 100: Difference signal enhancement means 101: L channel audio signal input terminal 102: R channel audio signal input terminal 103, 104, 107, 108, 110, 115, 116: Multiplier 105, 106: Subtractors 109, 111, 112, 117, 118: Adder

200: Crosstalk cancellation means 201, 202: Adder 203, 204: Delay device 205, 206: Low pass filter 207, 208, 211, 212: Multiplier 209, 210: High pass filter 213, 214: Subtractor 215: L channel Audio signal output terminal 216: R channel audio signal output terminal

300: Mid-low range emphasis means 301, 302, 315, 316: Adders 303, 304, 305, 306: Delay devices 307, 308, 311, 312: Multipliers 309, 310: Low-pass filters 313, 314: High-pass filters

401: L channel audio output 402: R channel crosstalk cancellation output 403: L channel crosstalk component 404: Crosstalk cancellation image 405: Direction of virtual speaker SP (DL) viewed from listener M

SP (L): L channel speaker SP (R): R channel speaker SP (DL): L channel virtual speaker M: Listener EL: Left ear ER: Right ear

Claims

Difference signal enhancement means for inputting an L channel audio signal and an R channel audio signal and outputting an L side difference signal enhancement signal and an R side difference signal enhancement signal, and an L channel difference signal enhancement signal from the L channel speaker to the right ear. An acoustic signal processing apparatus comprising: a crosstalk canceling unit that cancels a transmitted crosstalk component and cancels a crosstalk component transmitted from the R channel speaker to the left ear from the R side difference signal enhancement signal ,
The difference signal enhancement means comprises an L side difference signal enhancement means and an R side difference signal enhancement means,
The crosstalk cancellation means comprises an L side crosstalk cancellation means and an R side crosstalk cancellation means,
The L-side difference signal enhancement means, said and R channel audio signals L side difference signal obtained by subtracting the amplified signal from the L channel audio signal in less than one amplification factor of 0.5 or more, the L channel audio signal 0 A center signal obtained by adding a signal amplified with an amplification factor of 0.5 and a signal obtained by amplifying the R channel audio signal with an amplification factor of 0.5 and amplifying with an amplification factor of more than 0 and 0.5 or less. The low frequency component having a cutoff frequency of 7 kHz or more and 11 kHz or less is extracted from the added signal, amplified with an amplification factor of more than 0 and 2.0 or less, added to the L channel audio signal , and the L side difference Output as signal enhancement signal,
The R side difference signal enhancement means adds an R side difference signal obtained by subtracting a signal obtained by amplifying the L channel audio signal with an amplification factor of 0.5 or more and less than 1 from the R channel audio signal, and the center signal. The low frequency component having a cutoff frequency of 7 kHz or more and 11 kHz or less is extracted from the added signal, amplified with an amplification factor of more than 0 and 2.0 or less, added to the R channel audio signal , and the R side difference signal enhancement Output as a signal,
The L-side crosstalk canceling unit inputs the R-side difference signal emphasizing signal, delays the first delay of 1 ms or less (but not 0), and generates a low frequency component having a cutoff frequency of 1 kHz or more and 11 kHz or less. A first feedback process is performed in which a signal that has been extracted and amplified at an amplification factor of 0.5 or less is added to the R-side difference signal enhancement signal, and the frequency of the first delayed signal is 100 Hz or more. A low frequency range of 300 Hz or less is removed, and a signal obtained by amplifying with an amplification factor of more than 0 and 0.7 or less is generated as an L side crosstalk cancellation signal, which is subtracted from the L side difference signal enhancement signal. The signal is the L side channel audio output signal,
The R-side crosstalk canceling unit inputs the L-side difference signal emphasizing signal, delays the second delay of 1 ms or less (but not 0), and generates a low frequency component having a cutoff frequency of 1 kHz or more and 11 kHz or less. A second feedback process is performed in which a signal that has been extracted and amplified with an amplification factor of 0.5 or less is added to the L-side difference signal emphasizing signal, and the frequency of the second delayed signal is 100 Hz or more. A signal obtained by removing the low frequency range of 300 Hz or less and amplifying with an amplification factor exceeding 0 and 0.7 or less is generated as an R-side crosstalk cancellation signal, which is subtracted from the R-side difference signal enhancement signal. The signal is the R side channel audio output signal,
An acoustic signal processing device.

The acoustic signal processing device according to claim 1,
Furthermore, it is provided with a medium and low range emphasis means comprising an L side middle and low range emphasis means and an R side middle and low range emphasis means
The L-side mid / low range emphasis means receives the L-side difference signal emphasis signal and receives a third delay of 1 ms or less (but not 0) followed by a fourth delay of 1 ms or less (but not 0). The third feedback processing is performed to add the signal amplified with an amplification factor of more than 0 and 0.5 or less to the L-side difference signal emphasizing signal, and the frequency from the third delayed signal is increased. Removes the high frequency range of 800 Hz or more, amplifies it with an amplification factor of more than 0 and less than 0.5, extracts the high frequency range above the lowest resonance frequency of the reproduction speaker, and uses the L side channel audio as the L side mid / low range emphasis signal Add to the output signal
The R-side mid / low range emphasis means inputs the R-side difference signal emphasis signal, and receives a fifth delay of 1 ms or less (but not 0) followed by 1 ms or less (but not 0). The fourth feedback processing is performed to add the signal amplified with an amplification factor of more than 0 and 0.5 or less to the R side difference signal emphasizing signal after the delay of 0, and the frequency from the signal with the fifth delay Removes the high frequency range of 800 Hz or more, amplifies it with an amplification factor of more than 0 and less than 0.5, extracts the high frequency range above the lowest resonance frequency of the reproduction speaker, and uses the R side channel sound as the R side mid / low range emphasis signal Add to the output signal,
An acoustic signal processing device.