EP3090575B1 - Method for audio reproduction in a multi-channel sound system - Google Patents

Description

The invention relates to a device according to the preamble of claim 1.
A device of the type mentioned is known in the art and is in the US 5 412 732 A discloses a method for audio playback in a multi-channel sound system in this apparatus. Next is from the WO 2011/119401 A2 a video display, in particular a television, with an arrangement of speakers in a lower and upper listening level, known.

In three-dimensional audio playback in a multi-channel sound system, a higher listening level is added to the lower listening level. Herein lies the significant advantage of the audio reproduction method in a multi-channel sound system, since the human ear can clearly perceive and differentiate upwardly staggered sounds, so that the listener can enjoy an extended sound experience through three-dimensional loudspeaker arrangements. Incidentally, these methods have been mainly developed for sound signals in large rooms such as movie theaters.
In the prior art, different views are presented as to which speaker configurations or modes of generating the three-dimensional sound, whether channel or object based, result in an optimal sound experience, with either multichannel recording and reproduction of a three-dimensional sound space, as in US Pat WO 01/47319 A2 or the upmix of variable input channels offered by various providers to form a three-dimensional sound space in the foreground of the considerations. For example, Dolby Laboratories' three-dimensional audio systems have up to 64 speakers (eg, Dolby Atmos), which requires a corresponding number of output signals.

These methods have in common that a complex speaker configuration and thus a corresponding increased number of output signals is required to generate the desired three-dimensional sound space.

Even a loudspeaker configuration in a 9.1 three-dimensional sound system, which is suitable for a home theater, for example, consists of ten loudspeakers, which in turn requires a corresponding number of output signals for the lower and upper listening levels.

However, in the current state of the art, consumers accustomed to AV devices (audio video equipment) find it difficult to enjoy the benefits of this three-dimensional audio reproduction, since only a few are left with the costly facilities with three-dimensional audio playback and only a limited number of consumers have the appropriate premises in which it is possible to realize an increased number of loudspeakers including wiring. The reality is that while cinemas, music studios or even selected concert halls have the technology of three-dimensional audio playback, but it does not enter the everyday life of those who simply and easily, for example, at the workplace or in the living room or traveling with little effort and comparatively low budget in the advantage of three-dimensional audio playback.

It is therefore an object of the invention to develop a device of the type mentioned in such a way that these disadvantages are eliminated.

This object is achieved with the features of claim 1. Advantageous embodiments of the invention will become apparent from the dependent claims.

Fig. 1

eine Lautsprecheranordnung eines 3D-Sound-Formats mit unterschiedlichen Hörebenen gemäß dem Stand der Technik,

Fig. 2

ein Verfahren gemäß der Erfindung,

Fig. 3 bis 8

verschiedene Ausführungsformen von erfindungsgemäßen Audio-Video-Geräten, in die ein Verfahren aus Fig. 2 integriert ist,

Fig. 9 bis 11

weitere Ausführungsformen des erfindungsgemäßen Verfahrens und

Fig.12

ein erfindungsgemäßes Gerät, in das ein erfindungsgemäßes Verfahren gemäß der Ausführungsform in Figur 11 integriert ist.

Fig. 1 zeigt eine herkömmliche dreidimensionale Audiowiedergabe in einem mit einem Hörer 3 besetzten größeren Raum 2 im Rahmen eines 9.1 Surround-Sound-Formats. In dem Raum 2 sind mehrere Lautsprecher einer Lautsprecheranordnung 5 verteilt, den untere sowie höhere, d.h. obere Hörebenen 4a, 4b, 5a, 5b zugeordnet sind.
Im vorderen Bereich des Raums 2 befinden sich die obere Hörebene 4a mit zwei Lautsprechern mit dem linken höheren Signal L_Hi und dem rechten höheren Signal R_Hi als Ausgangssignale. Weiterhin befindet sich in dem vorderen Bereich des Raums 2 die untere Hörebene 5a mit vier Lautsprechern mit dem linken Signal L, dem Kanal C (Center/Mitte), dem rechten Kanal R und dem Kanal LFE (Low Frequency Effect) als Ausgangssignale. Im hinteren Bereich des Raums 2 befinden sich die obere Hörebene 4b mit zwei Lautsprechern mit dem linken höheren Surroundsignal S_L,hi und dem rechten höheren Surroundsignal S_R,hi als Ausgangssignale. Weiterhin befindet sich in dem vorderen Bereich des Raums 2 die untere Hörebene 5b mit zwei Lautsprechern mit den beiden Surroundsignalen S_L, S_R als Ausgangssignale.The invention provides that, from the input channels provided for the input channels R and L, channels are decoded which lead to output signals the higher, ie the upper listening level are further processed. The core idea of the invention is to provide a device which, while generating a minimum number of output signals, can reflect a three-dimensional audio reproduction and at the same time covers both the mono and the stereo region.
This results in a smallest unit, which can preferably be extended in a modular manner by the output signals serve as further input signals to further lower and upper listening levels and thus to produce an even more complex speaker configuration.
By means of the device according to the invention and the software corresponding thereto, it is possible, for example in domestic televisions or laptops, to realize the increased sound level by adding two small loudspeakers.
The decoded channels are preferably a left-hand spatial channel R _L = LR, a right-hand spatial channel R _R = RL and a center channel C = L + R. Expediently, linear and parallel channels R and L are generated from these input channels for these decoded channels, which channels preferably serve as output channels for the lower listening level. Practical variants of the invention provide that stereo signals or mono signals are generated for the signals in the lower and upper listening levels.
In the following the invention will be explained in more detail with reference to the drawings. It shows in a schematic representation:

Fig. 1

a loudspeaker arrangement of a 3D sound format with different listening levels according to the prior art,

Fig. 2

a method according to the invention,

Fig. 3 to 8

various embodiments of audio-video devices according to the invention, in which a method Fig. 2 is integrated,

Fig. 9 to 11

further embodiments of the method according to the invention and

Figure 12

an inventive device, in which a method according to the invention according to the embodiment in FIG. 11 is integrated.

Fig. 1 shows a conventional three-dimensional audio playback in a occupied with a handset 3 larger space 2 in the context of a 9.1 surround sound format. In the room 2, a plurality of loudspeakers of a loudspeaker arrangement 5 are distributed, the lower and higher, ie upper listening levels 4a, 4b, 5a, 5b are assigned.
In the front area of the room 2 are the upper listening level 4a with two loudspeakers with the left higher signal L _Hi and the right higher signal R _Hi as output signals. Further, in the front area of the room 2, the lower listening level 5a having four loudspeakers with the left signal L, the channel C (center), the right channel R and the channel LFE (Low Frequency Effect) as output signals. In the rear area of the room 2 are the upper listening level 4b with two speakers with the left higher surround signal S _{L, hi} and the right higher surround signal S _{R, hi} as output signals. Furthermore, located in the front area of the room 2, the lower listening level 5b with two speakers with the two surround signals S _L , S _R as output signals.

Before the signals in the lower and upper listening levels 4a, 4b, 5a, 5b are distributed to the loudspeakers, they have been processed in the context of a multi-channel sound system and on the basis of the input signals R and L by an audio processor provided for this purpose.

Fig. 2 shows the inventive method, starting from the two input channels R and L via linear and parallel channels guided 8.9 the output signals R and L in the lower listening plane 7 and in the upper listening plane 6, the left output signal L _Hi and the right output signal R _Hi generates four output signals, two for the top and two for the lower listening level. For the implementation of the method is a signal processor in the form of an audio processor, on which there is a software. The software contains an algorithm which is processed by the signal processor, the algorithm detecting the method.

In the upper listening level 6 are how Fig. 2 further shows, proceeding from the two input signals L and R further process steps.

• eine Decodierung ,
• eine Signalsteuerung,
• eine Phasenkorrektur,
• eine Frequenzjustierung,
• eine Encodierung,
• eine Master-Sektion.

In detail, the procedural sections are:

• a decoding,
• a signal control,
• a phase correction,
• a frequency adjustment,
• an encoding,
• a master section.

Three channels are first decoded from the two input signals L and R and formed parallel to the channels 8, 9 which are guided linearly to the output. This produces the upper listening plane 6, while the channels 8, 9 which are guided linearly to the output form the lower listening plane 7.

The decoded channels are the left spatial channel R _L = LR, the right space channel R _R = RL and the center channel L + R

The channels R _L and R _R map the premises and reflections within the input signals L, R, whereas the channel C (center channel) maps the addition of both input channels L, R. This makes it possible to further process the input signals L, R, if it is a mono signal. If a mono signal is present at the input, the channels R _L and R _R remain silent and the channel C carries on the signal information and thus makes further signal processing possible.

After this encoding step, the channel R _{R is} fed to the signal detector 10. This outputs the control signal "1" when the signal strength of R _R falls below the selected threshold level and the control signal "0" when the level of the channel R _R rises above the selected threshold level. The threshold level is -20dB and the response time (trigger) is zero seconds.

The control signals of the signal detector 10 are multiplied by the signal multiplier 11 with the signal of the center channel. If there is no detected signal in the channel R _R , so that no stereo signal in the channels R _L and R _R above or equal to the set by the threshold level signal strength and the signal detector 10 generates the control signal "1", the channel C with Multiplied by "1" and sent for further processing. If a detected signal is present in the channel R _R , so that a stereo signal in the channels R _L and R _{R is} above or equal to the signal strength defined by the threshold level and the signal detector 10 generates the control signal "0", the channel C is included "0" multiplied and not released for further processing, since the signal is equal to zero, so that it is unequivocally detected whether a stereo signal is present.

In order to avoid a phase rotation of the channels R _L , R _R , as FIG. 2 further clarifies, in a next step, a phase correction made to convert the signal from the channels R _L and R _R in a phase-pure stereo signal. This is achieved by using a delay 12 in the channel R _R. The channel R _R is delayed to the channel R _L so that the phases of both channels in a non-phase-rotated audio signal in stereo to each other. The delay time is 140 samples with a clock rate of 48khz and 16bit.

In order to enhance the later impression of a reflection for the upper listening plane 6, the C channel is also readjusted in its phase by a delay 13, which is applied to the channel C _R , after the channel C (L + R) after the signal multiplier 11 has been split into the channels C _L and C _R and has thus been continued in dual-mono channels. The channel C is a pure mono channel and can be converted by the splitting into the two duo mono channels C _L and C _R and the delay of the channel C _R to C _L by a delay in a stereo signal with a phase correlation above zero. This creates the auditory impression of an increased diffusivity of the original signal, which contributes to the impression of the range of increased hearing, as a mono signal, which was recorded with increased installed microphones, depending on the nature of the receiving space and the height of the attached microphones, also not linear but diffuse and with reflections, depicts.

As part of a further process step, the frequency adjustment of the center channel C by means of the equalizer 14. The frequency adjustment of the channel C adjusts its frequency dependent mapping in the later output signals L _Hi , R _Hi the upper listening level 6, regardless of the later frequency adjustment of the output signal , As a result, the sound character of the output signals L _Hi , R _Hi optimally on in the Fig. 3 to 8 shown AV device can be emitted via these two channels

Encoding as a further process step sums the stereo signal the channels R _L , R _R with the stereo signal of the channels C _L , C _R to the channels L _t , R _t in such a way that the channels R _L and C _L the channel L _t and the channels C _R and R _R the Form channel R _t . The summation is accompanied by a level adjustment at the level controls 15, 16, 17, 18, since the levels of the newly formed channels L _t , R _{t increase} by the described summation of the channels R _L , RR with C _L , CR. The level adjustment lowers the levels R _L , R _R , C _L , C _R accordingly, so that their summation can not lead to overdriving. Encoding now provides a stereo signal, which can be enhanced by the subsequent master section and also played back by commercially available audio playback components. Alternatively, it is also possible to generate two independent stereo signals by not encoding the channels R _L , R _R and C _L , C _R so that four output signals result in the upper listening plane 6.

In order to amplify the auditory impression of a "sound reflection upwards", the signals L _t , R _t as off Fig. 2 further, within the framework of the master section, adjusted individually for their later use in its frequency responses via the equalizers 19, 20. Depending on the desired radiation characteristics, the signals L _t , R _t appear farther from the original sound source. Also here the effect of the sound emission can be imitated by a frequency response. The further away it is from the original sound source, the more the upper frequencies can be lowered by a low-pass filter. It is also possible by the frequency adjustment to optimally tune the sound result to the speaker or speakers, which emits the output signals L _Hi , R _Hi later.

Through the use of a reverb or / and a stereo delay 21 which are admixed to the signal L _t , R _t in a ratio which is adjusted individually and according to the method of use of the method, a spatiality, and a sound delay is shown. This ensures that the output signals L _Hi , R _{Hi of} the upper listening level 6 also different Rooms and sound delays can be represented by the use of different, storable presets (Presets) to adapt the sound even closer to a true "sound reflection up", as well as the individual sound ideas of the manufacturer and / or users.

To amplify the feeling even further that the output signals L _Hi , R _Hi sound reproduce, the "from below hochschallt", as Fig. 2 shows a compression stage used in the master section. The adjustment of the compressor 22 or a limiter ensures that the signal is smoothed so that the sound peaks can be intercepted and the quieter parts of the audio signal L _{t, Hi} , R _{t, Hi} can be raised. This enhances the auditory impression of the diffused and distant sound, since sound peaks preferably occur and decrease in the vicinity of a sound source the farther the receiving microphone is moved upwardly therefrom. In addition, it is possible by compression to adjust the ratio of the dynamics to the channels L, R in the lower listening plane 7.

Another method step provides the level adjustment of the channels L _{t, Hi} , R _{t, Hi} at the level controls 23, 24 by the output level is adjusted in relation to channels of the lower listening plane 7, so that the impression of increased hearing perfectly on the respective Listening situation can be coordinated. Alternatively, it is also possible to add the audio signal L _{t, Hi} , R _{t, Hi to} the channels L, R again in order to be able to display an increased sound impression even in loudspeaker systems with only two loudspeakers or even only one.

• Phasenkorrektur:
  Delay-Zeit: 140 Samples bei Taktung 48khz, 16bit
• Phasenjustierung C-Kanal:
  Delay-Zeit: 10 Samples bei Taktung 48khz, 16bit
• Frequenzjustierung C-Kanal:
  High Pass Filter: Grenzfrequenz bei 200 Hz, Gain = 0, Q-Faktor= 1.41 Low Pass Filter: Grenzfrequenz bei 3000 Hz, Gain = 0, Q-Faktor= 1.41
• Encodierung:
  Die Pegel werden so justiert, dass die encodierte Summierung der Kanäle R_L, R_R, C_L, C_R den gleichen Pegel hat (dB) wie der von R_L,R_R vor der Summierung
• Master-Sektion / Frequenzjustierung;
  HighPass Filter: Grenzfrequenz bei 200 Hz, Gain = 0, Q-Faktor= 1.41 LowPass Filter: Grenzfrequenz bei 3000 Hz, Gain = 0, Q-Faktor= 1.41
• Master-Sektion / Räumlichkeit / Reflektion:
  Individuell justierbar, keine idealen Einstellungen, hängt vom Einsatz des Verfahrens ab. Vorteilhaft sind beim Hall kurze Decay, also Abschwillzeiten von 0,51 Sekunden bis 0,67 Sekunden und einem Predelay von 20 Millisekunden
• Master-Sektion / Compression:
  • Threshold: -10 dB
  • Ratio: 8:00:1
  • Attack: 0,46 Millisekunden
  • Release: 560 Millisekunden
  • Knee: 80
• Master-Sektion Pegeljustierung (dB):
  Die Pegeljustierung ist individuell auf das Gerät/das Umfeld einstellbar, in dem das Verfahren eingesetzt werden soll

The following parameters can be considered for the individual process steps:

• Phase correction:
  Delay time: 140 samples at 48khz, 16bit clocking
• Phase adjustment C channel:
  Delay time: 10 samples at 48khz, 16bit clocking
• Frequency adjustment C channel:
  High Pass Filter: cut-off frequency at 200 Hz, gain = 0, Q-factor = 1.41 Low Pass Filter: cut-off frequency at 3000 Hz, gain = 0, Q-factor = 1.41
• encoding:
  The levels are adjusted so that the encoded summation of the channels R _L , R _R , C _L , C _{R has} the same level (dB) as that of R _L , R _R before the summation
• Master section / frequency adjustment;
  HighPass filter: cutoff frequency at 200 Hz, gain = 0, Q factor = 1.41 LowPass filter: cutoff frequency at 3000 Hz, gain = 0, Q factor = 1.41
• Master Section / Spatiality / Reflection:
  Individually adjustable, no ideal settings, depends on the use of the method. Hall decay is short, so swells from 0.51 seconds to 0.67 seconds and a predelay of 20 milliseconds
• Master Section / Compression:
  • Threshold: -10 dB
  • Ratio: 8: 00: 1
  • Attack: 0.46 milliseconds
  • Release: 560 milliseconds
  • Knee: 80
• Master section Level adjustment (dB):
  The level adjustment is individually adjustable to the device / environment in which the method is to be used

The FIGS. 3 to 8 show audio-video devices (AV devices), in which the inventive method is integrated. For this, the AV devices each have a in the FIGS. 3 to 8 Not shown signal processor on which a software is located. The software contains an algorithm that is processed by the signal processor in the form of an audio processor, wherein the algorithm detects the inventive method. The in the Fig. 3 to 7 It is common in the case of the AV devices shown here that they also have picture input and picture output channels in addition to audio input and audio output channels.

AV devices, such as a TV (TV) and an in the Fig. 3a, 3b flatscreen shown 28 have not, as before, only one or two speakers for emitting mono or stereo sound, but three speakers 26, 27 for the monaural sound ( Fig. 3b ) or four speakers 26, 27 for the stereo sound ( Fig. 3a ), since the upper listening level has been added. The upper listening plane is to some extent extracted from the lower listening plane by the in Fig. 2 Encoding described what in the Fig. 3 to 8 indicated by the dashed arrows. The loudspeakers 26, 27 are conventionally installed according to individual equipment requirements and mounted so as to allow a self-tuned listening field. It is also possible, for example, to let the loudspeakers of the upper listening plane radiate upwards in order to make the listening field to become even more diffuse upwards.

Further application examples are a mobile PC 25 ( Fig. 4a, 4b ), a Tablet PC 29 ( Fig. 5a, 5b ) as well as a smartphone 31 ( Fig. 7a, 7b ) in fact in both vertical and horizontal usage and a radio 32 ( Fig. 8a, 8b ).

Even a soundbar 33 will not look like Fig. 6a, 6b shows, used only to reproduce the overall sound of an AV device, such as a television, but according to the invention also for the blasting of the extracted upper listening plane. This results in new speaker constellations within these types of devices because z. As well as a soundbar with individual outputs according to the invention for the upper listening level, the otherwise no longer active loudspeakers of the TV set with the new signals of the upper listening level while operating a sound bar and thus can operate the TV more economically. Since a stereo signal is also generated within the scope of the invention, it can in turn be combined in the AV devices with matrix surround decoders in order also to subject the sound of the upper listening level to a surround decoding. This makes it possible to extract an entire upper listening plane forward and backward.

The present invention is not limited in its execution to the embodiments given above. Rather, a number of variants is conceivable, which make use of the solution shown in other types. For example, the channels 8, 9 in the lower listening plane 7 can also be processed further.

The inventive principle of the modularly expandable smallest unit of signal generation, which leads to complex speaker configurations, also illustrates FIG. 9 ,

Starting from the two input channels R and L, by means of an algorithm in the signal processor 34, the output signals R and L in the lower listening plane 7 and in the upper listening plane 6, the left output signal L _Hi and the right output signal R _Hi generated, so initially four output signals, two for the upper listening level 6 and two for the lower listening level 7, are generated.

In the upper listening plane 6 then, as out FIG. 9 further, the left output signal L _Hi and the right output signal R _{Hi are added} to a mono signal L _Hi + R _Hi and supplied to a first speaker 35.

The output signals R and L in the lower listening level 7 are routed as channels L ₁ and R ₁ directly to the speakers 36, 37 of the soundbar 40. At the same time, the output signals R and L serve as input signals R and L in order to generate a lower hearing level 7 and an upper hearing level 6 again in the context of the method according to the invention, which in turn takes place by means of the algorithm in the signal processor 34 on which the software is located. The software contains an algorithm, which is processed by the signal processor.
Here, starting from the splitting of the input signals R and L, the output signals R and L in the lower listening level 7 and in the upper listening level 6, the left output signal L _Hi and the right output signal R _Hi generated, so again four output signals, two for the upper listening plane, 6 ie L _Hi and R _Hi , and two for the lower listening plane 7, ie L and R, are generated. Thereafter, the signals L _Hi and R _{Hi are added to} the signals R and L in the lower listening plane 7, ie, L _Hi is added to the signal R with the signal L and R _Hi . The added or mixed signals are thereby supplied to two further speakers 38, 39 of the soundbar 40 in the lower listening level. The soundbar 40 thus has a total of five output channels, namely four output signals R, L, L _Hi + L, R _Hi + R in the lower listening level 7 and an output signal L _Hi + R _Hi in the upper listening level 6, all output channels also by level control , Equalizer, compressor etc. can be processed.

In the FIG. 9 shown variant of a modular expandable smallest unit can be in a soundbar, like FIG. 10 yet to be supplemented by a bass box (subwoofer) 41. This will be how FIG. 10 illustrates that the output signals R and L in the lower listening plane in the signal sequence before their redistribution add together are sent through a lowpass filter 42 and simultaneously processed as R and L signals in the signal processor 34.

Another variant of the inventive principle of the modularly expandable smallest unit of signal generation, which leads to complex speaker configurations, also illustrates FIG. 11 ,

Fig. 11 shows the inventive method, the two input channels R _t1 and L _t1 , which arise from the summations R + C and L + C (C = center channel), the output _signals R _1Hi and L _1Hi in the upper listening plane 7 and in the lower listening plane 6, the left output signal L ₁ and the right output signal R _{1 are} generated, so that four output signals, two for the upper and two for the lower listening level, are generated. Here, too, the signal processor 34 is used for the generation, specifically in the form of an audio processor, on which there is a software containing the algorithm.

In the FIG. 11 shown embodiment of the method according to the invention differs from the in FIG. 10 described in that the generated output _signals R _1Hi , L _1Hi , L ₁ and R ₁ do not serve as input signals again, but in the processor 34 in parallel two further input signals S _R and S _{L are processed} in the form of surround signals to output signals by a parallel processing into the output _signals R _2Hi , L _2Hi , L ₂ and R ₂ in the upper and lower listening levels are decoded. The two output signals L ₁ , L ₂ and the two output signals R ₁ , R ₂ are sent to the speakers of the lower listening level 6, whereas the output _signals L _1Hi , R _1Hi , L _2Hi and R _2Hi the upper listening level 7, such as FIG. 11 is further clarified, summed to signals R _tHi , L _tHi the upper listening level 7, the speakers of the upper listening level 7 are supplied.

The further channel LFE is led directly to a separate output and fed there as an output channel LFE another speaker, this output channel, as well as all other output channels, also by level control, equalizer, compressor, etc. can be processed. The speaker configuration of an audio device connected to the in FIG. 11 described embodiment corresponds illustrated FIG. 12 ,

Both in the Figures 10 and 11 In common with the embodiments shown, it is common that the method according to the invention is repeatedly executed in the signal processor 34.

LIST OF REFERENCE NUMBERS

2

room

3

receiver

5

Speaker layout

4a, 4b, 6

upper listening level

5a, 5b, 7

lower listening level

8.9

channels

10

signal detector

11

signal multiplier

12,13,21

delay

14,19,20

equalizer

15.16

level control

17.18

level control

22

compressor

23.24

level control

25

PC

26.27

speaker

28

flatscreen

29

PC

31

Smartphone

32

radio

33

Soundbar

34

signal processor

35,36,37

speaker

38.39

speaker

40

Soundbar

41

Bassbox

42

Lowpass filter

Claims (9)

1. Device having sound input channels and sound output channels and also a processor, wherein loudspeakers (26, 27, 33) are assigned to the device, and software is located on the processor, which software contains an algorithm which is executed by the processor, wherein the algorithm comprises a method for audio reproduction in a multi-channel sound system having two input signals L and R, wherein output signals are generated for different listening levels, wherein only one lower listening level (7) and only one upper listening level (6) are generated and a maximum of six output signals, with a maximum of two output signals for the lower listening level (7) and a maximum of four output signals for the upper listening level (6), are generated, wherein stereo signals and/or mono signals are generated for the signals in the lower listening level (7) and upper listening level (6), characterized in that the loudspeakers (26, 27, 28) are integrated into the device and/or are arranged directly on the device, and wherein channels are decoded from the input channels intended for the input channels R and L, which channels are processed further to output signals of the upper listening level (6).
2. Device according to claim 1, characterized in that mono signals are generated for the signals in the lower listening level (7).
3. Device according to claim 1, characterized in that mono signals are generated for the signals in the upper listening level (7).
4. Device according to one of the claims 1 to 3, characterized in that the output signals serve as further input signals.
5. Device according to one of the claims 1 to 4, characterized in that the decoded channels are generated in the form of a left spatial channel R_L = L-R, a right spatial channel R_R = R-L as well as a center channel C = L+R.
6. Device according to one of the preceding claims, characterized in that channels (8, 9), guided linear and parallel to the decoded channels, are generated from the input channels.
7. Device according to one of the preceding claims, characterized in that at least a portion of the input channels and/or the output channels are added to one another.
8. Device according to one of the preceding claims, characterized in that, at most, two output signals for the lower listening level (7) and, at most, two output signals for the upper listening level (6) are generated.
9. Device according to one of the preceding claims, characterized in that it has image input channels and image output channels.

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