DE202010012133U1 - Device for changing an audio signal via its frequency response - Google Patents

Abstract

Device for modifying an audio signal over its frequency range within at least one frequency band, essentially consisting of a processing unit (10) with an interface (11), wherein the processing unit (10) includes signal processing (7) to which an audio signal (9) is supplied , characterized in that the signal processing (7) the audio signal (9) is supplied, and that at least one further interface (4) is present, by means of the default parameter (21) can be changed and entered individually in their absolute value, wherein an interface output (42) a dynamic processor (5) is connected downstream, whose changed control variables are also supplied to the signal processing (7), and that at the audio output (8) of the signal processing (7) a processed audio signal (13) is applied.

Description

The The invention relates firstly to a device for modification an audio signal over its frequency range according to the Preamble of claim 1.

It is a device for the dynamic correction in the transmission of audio signals, in which the dynamics at different frequency components is stretched or pressed by means of frequency-dependent control, according to the DE-AS 1 282 722 known. In this case, with regard to the frequency- and volume-dependent human auditory sensitivity, the control behavior of the dynamic correction device is designed such that the listener actually hears the full or at least approximately full frequency range of the original performance, both in loud and in low-loud passages of the presented program.

An apparatus and method for multiband compression of audio input signals relates to DE 698 04 096 T2 , In this case, such a compressor is to be created, which shows no unwanted artifacts at filter cut-off frequencies, as can occur with hearing aids in narrowband signals as well as broadband signals. Therefore, a filter bank is used which has a plurality of filters for filtering an audio signal. Further, there are a plurality of gain calculators for calculating a gain applied to each band.

Also by the DE 102 07 200 A1 describe a dynamic volume and tone control, which should include auditory physiological properties of the human hearing system. The control system combines all essential features of the frequency, time and dynamic range in a multi-dimensional map. A signal processor generates from it by analysis of the music, in real time all necessary control parameters to the frequency response and level dynamics and time correction. Such a volume and tone control is suitable for installation in LF amplifiers for music playback via speakers.

An apparatus and method for automatically compensating for a multi-channel audio system are disclosed in U.S. Patent No. 5,839,074 DE 197 20 217 A1 described. It should be noted that white noise generated by a measuring part for measuring transmission characteristic is also reproduced via speakers. Transmission signals from the respective speakers are collected by a microphone assembly at a listening position to transmit the collected signals to a calculation part for calculating a transfer function.

The DE 691 30 528 D2 Indicates a sound mixer that allows interactive control of multiple parameters affecting an audio output. Audio input signals are thereby mixed to direct the position of the signal relative to a listener and to control the relative level of an input signal with respect to other input signals. External processing equipment such as dynamics, compressors, limiters, equalizers and units of light, delay units are used to achieve certain effects. The object of this invention is to improve a sound mixer so that it can immediately perceive and assess the conditions of the various parameters of the audio mix. To achieve this object, a control device is used with a visual display device for displaying an icon. An input device (for example, a mouse) is used to control the position of the icon on the screen. The controller thereby generates a multi-parametric control signal based on the position of the icon and used by a sound signal processing circuit so as to control a plurality of parameters affecting a sound output.

The DE 10 2008 023 919 A1 describes a circuit of a multi-band compressor for processing sound signals with an input amplifier to the amplifier of an input signal, wherein the amplified input signal via a main path as bypass line unchanged and over one or more secondary paths as a circuit for processing the amplified input signal processed to an output amplifier for amplifying and outputting the processed Signals are each of the amplified input signal, which are routed through the main path and the secondary path or to the output amplifier by means of a respective setting means and in the Nebenweg each an equalizer filter for filtering a respective frequency range with dynamic circuit for the possible dynamic change of frequency , Amplitude and phase depending on the signal is provided simultaneously with a static control. There is also a low pass filter, a bandpass filter and a high pass filter.

About that In addition, digital graphic / parametric equalizer with equalizer function known to the skilled person.

In the case of audio recordings, for example, traffic noise, impact sound, hum or other unwanted sound images are constantly appearing, which lead to an imbalance of the entire sound experience to be presented. In In such a case, an equalization is announced, which makes an increase or decrease of very specific selected frequency ranges for sound color change necessary. In this case, such an equalizer is used to correct the sound image. This is usually realized by high, low and bell filter. With a graphic equalization, which is inflexible in specific applications by fixed frequency bands, a lot of space is required and is therefore difficult to integrate. In parametric equalization, on the other hand, all parameters can be set independently, but with a fixed number of overlapping frequency bands, making things very confusing. Such parametric equalizers are today standard in all mixing consoles.

So are the first means of today's use parametric equalizer in use. You have different ribbons here, one can Set frequency, raise or lower and the goodness for the bandwidth. This is a high quality used for a narrow band, for example. This but can also be converted into other qualities. These are only the parameters with which one trying to improve the sound, by simply playing a piece to make it sound better and set it statically. You can only use these parameters via a static setting make. The attitude then remains over the entire Time course received or until at least one setting is changed by the user. By using sound editing programs it is also possible to automate this. It reproduces the mixer exactly what is set. In that you can only limited targeted this static setting to a small extent influence. A sound engineer always has to make the individual changes himself set for this. This is what today, for example performs an equalizer. Even if an equalizer with multiple bands provided the same procedure is always followed. The sound engineer here has a frequency spectrum in which he can Put straps as you want.

The The object of the invention is an improvement of the cited prior the technique of change or adaptation to change in the individual frequency bands, to get a quality improvement of the audio signal or to reshape the sound.

The The object of the invention is achieved by a device according to claim 1 solved. The dependent claims give it a further embodiment of the inventive concept again.

In a first preferred embodiment, for example in the case of a user interface of an equalizer, another processing stage switched between or added. This will achieved that in the editing stage more information about the change of the frequency band than in a normal equalizer. Through this Approach, providing additional parameters, is the Equalizer capable of more than the usual Parameters about the processing level for separate To edit frequency bands. The good order It should be noted that this is not exclusively related with an equalizer, but also with different ones technical devices for the processing of audio signals. It is possible that no additional Parameters, for example when switching off this auxiliary device, supplied to the editing stage and the sound mixing in normal extent expires.

Becomes however, the accessory which includes a processor turned on, then the level within a frequency band automatically determined. After the level is detected, will set a threshold with a suitable parameter. there the threshold value is one of the first parameters to be newly entered which then sets a ratio should. The ratio is the ratio by which the absolute value can be changed. For example, with positive values, if the audio signal is above the threshold, is done a processing and negative values when the audio signal Below the threshold, there is also a processing. In other words, through this threshold and the ratio becomes set to what extent the otherwise static gain factor (the gain or the reduction) changed becomes. In this case, a modulation depending on the input signal performed.

The difference to the invention and, for example, a multi-band compressor becomes clear that quite different characteristics can be set with the invention, for example with a narrow-band filter. Such an application may be, for example, that no change takes place due to the dynamic processing at a fixed frequency. At the moment when the level drops in this frequency band to be processed, but falls below the threshold value and falls below a fixed value, the invention immediately decreases the frequency, for example, with a ratio of a certain ratio. Such an application is about when film dialogues in which, for example, noise such as hum, or lamps sirren, or camera siren as long as is spoken, are covered. In the moment when silence prevails, however, this disturbance comes to light as a disturbance frequency. In today's application to the prior art The sound engineer also turns these frequencies out of the language and has to go manually and readjust everything in painstaking detail for every small area where there is no talk. By means of the present invention, such processes would be much faster to implement, since they proceed dynamically over the processed frequency band.

A possible approach of a sound engineer is to be understood as that first a static setting is considered and it is then an approach to a satisfactory result. By the present invention in the form of a dynamic Automatimusses the whole thing is reproducible, so an optimum of quality get. The advantage of the invention lies in the fact that the setting is retained until a change one of the parameters or all parameters takes place.

in the Meaning of the invention is, in addition to a deliberate manual change the parameter also carry out an automation of the parameters to be able to. This is always aligned to a frequency band, so that in multi-band devices, the invention of course in a multiple number is used.

at The present invention is not concerned with the invention to determine an ideal setting itself, if, for example a frequency is lowered, but it is about that the invention It helps to decide how much the frequency response should be lowered or raised. This means that the invention is an aid the sound engineer, for example, he is the normal used static setting over a period of time but if, for example, a change is necessary, so this can be done by entering the additional parameters to be changed.

simplified The whole procedure is characterized by being within one Program or multiple programs executed and stored be performed so that a dynamic processing of a sound sequence becomes. Thus, the program is a modulation of the setting for example, an equalizer or the like made. there the modulation happens automatically, but the sound engineer can still determine how much modulation takes place here.

The Invention thus provides an increase or decrease level-dependent, by manually changing parameters, the audio signal. In other words, there is a dynamic modulation. In so-called multiband compressors this is traditionally one static shape, because the input signal always into a specific Number of frequency bands is divided, which then edited and put together again. Become by the invention now almost the classic controls of an equalizer of an additional Program modulated or controlled. Through this form of editing will not affect the sound of the equalizer used taken. So is just for a balanced audio signal It is important that the moment the sound engineer every now and then the feeling of mixing has, that in principle everything fits quite well, but at certain (frequency-dependent) Make sure something has to be readjusted. These Correction could be carried out automatically by the invention.

The incoming audio signal contains the entire frequency spectrum. A frequency band is z. As any portion of the frequency spectrum designated or understood. A band of signal processing or A processing unit is called a processing component that is refers to a particular selected frequency band understood.

The Invention will be described below with reference to possible, however not conclusively demonstrated embodiments explained in more detail in the block examples.

It shows:

1 A first embodiment of the inventive concept;

2 a second possible embodiment of the inventive concept;

3 : a representation of the prior art;

4 a single view of a frequency band in another preferred embodiment;

5 : a representation of the processing of the parameters in a mono-execution;

6 : a possible waveform within a used processor;

7 FIG. 4 is an illustration of a frequency band according to the prior art; FIG.

8th a representation of a frequency band with a change by the invention;

9 : as 8th but with a further execution of a change.

In the 1 in the block diagram is a first preferred embodiment with a processing unit 10 been presented. This processing unit can 10 z. B. may be an equalizer, but it is also possible that any other version of a processing unit can be applied here. Within the processing unit 10 is a signal processing 7 contain, on the one hand, an audio input 1 an audio signal 9 receives, which, however, by a delay 6 can be delivered delayed. At the same time, however, also the audio signal 9 from the audio input 1 to a level determination 3 or possibly to a bandpass 2 once per band. Additional processing can be performed as often as in signal processing 7 Bands are present. Within each block, a frequency band is cut out, which is predestined for further processing and at the same time a measurement of the level is made. The calculation of the frequency band as well as the measurement of the level is still influenced by the fact that the bandpass / the level determination 2 . 3 also via a parameter information 44 a part of the still to be described, variable parameters is supplied. This can be done through an additional interface 4 done by means of the additional parameter or parameter information 45 can be entered. These parameters are always related to a frequency band and may be, for example, a static on / off, a static frequency, a static Q factor, a static gain (both gain and attenuation), or a static filter type selection. In addition to these static information, dynamic parameters can also be input in a changeable manner per frequency band. In particular, these may be a dynamic on / off, a dynamic threshold, a dynamic ratio, a dynamic attack, a dynamic release, and a dynamic peak / RMS (peak or average). The by means of the parameter input 45 selected parameters of the type described above need not all be changed, in this case it depends on the frequency band to be processed. From the interface 4 goes next to the parameter information described above 44 to the bandpass and the level determination 2 . 3 an interface output 42 to a dynamics processor 5 , This dynamics processor 5 will also be the level information 43 delivered, so from the level information 43 and the parameter information 42 the dynamics processor 5 generates an output signal, which signal processing 7 is supplied and for controlling the parameters of the signal processing 7 serves, this is not an audio signal. The signal processing 7 calculated according to the information supplied via the signal output 46 and the delayed audio signal 9 a processed audio signal 13 , which at the audio output 8th is applied.

For the sake of understanding, it should be noted that in order to practice the invention, one or more frequency bands are separated from the audio signal that the entire frequency spectrum contains, in order to be fed to a processing. It is necessary that the device used for processing per band at least one interface 4 and a dynamics processor 5 provides and optionally a bandpass 2 and a level determination 3 , For simplification, therefore, in the 1 on a representation of the multiple number of interface 4 , Bandpass 2 , Level determination 3 and dynamics processor 5 has been dispensed with. In the same way, this also applies to 2 to.

In this preferred embodiment of the 1 can the extra interface 4 already be part of a signal processing. The, the signal processing on the output signal 46 supplied parameters per frequency band are in particular on / off, the frequency, the Q-factor, the gain and the filter type. Thus, it becomes clear that the dynamics processor 5 Provides signals that correspond to the absolute parameters and contain no audio information. Audio editing is used exclusively in signal processing 7 carried out.

In the second preferred embodiment according to the 2 It is assumed that, for example, as a processing unit 10 an equalizer is present. This equalizer 10 has a built-in interface 11 , above which the normal parameter input for setting the equalizer 10 is made. About the audio input 1 becomes the audio signal 9 the delay unit 6 fed and from there to the signal processing 7 forwarded. At the same time, however, in this embodiment, the audio signal 9 to the dynamics processor 5 forwarded. The input of the parameters 45 happens in the same way as in the 1 via the additional interface 4 whose interface output 42 to the dynamics processor 5 is continued. At the same time gets the dynamics processor 5 also information from the interface 11 of the equalizer 10 , Also in this case, the dynamics processor calculates 5 the corresponding parameter changes and outputs them via the parameter output 46 to the signal processing 7 further. The signal processing 7 then delivers the edited audio signal 13 to the audio output 8th ,

According to the prior art (see 3 ) becomes, for example, an audio input 1 with a left channel 14 and right channel 15 shown, wherein an audio signal 9 to a processing unit 10 is forwarded in the form of an equalizer. This equalizer 10 accordingly processes the information supplied to it in the form of parameters sta table so that audio signal 9 , which is a processed audio signal 40 to the audio output 8th with the left channel 14 and the right channel 15 is delivered. Like such an audio signal 40 for a certain bandwidth 17 of a frequency band is shown as the prior art 7 , During processing by the processing unit 10 As a rule, a plurality of bands are connected in series. The representation of the curve 54 is quasi the frequency response of a frequency band in the 7 again. The calculation result 37 or the level information 43 become the frequency 53 applied.

The processing of individual bands or a single band and also the consideration of individual bands, the 4 according to the present invention in a possible preferred embodiment. Again, to understand the audio input with a left channel 14 and a right channel 15 been presented. The pending audio signals 9 each go over the delay 6 to the signal processing 7 or the processing unit 10 , At the same time the audio signal 9 of the channels 14 . 15 also to the dynamics processor 5 that has an additional interface 4 which in this case is part of the dynamics processor 5 is, forwarded. From the additional interface 4 and the dynamics processor 5 becomes a dynamic gain output 19 to the signal processing 7 or processing unit 10 forwarded. From the signal processing 7 and the processing unit 10 become the frequency 16 , the bandwidth 17 and a static gain 18 to the additional interface 4 and the dynamics processor 5 delivered.

With the circuit described above, it is possible that optionally of the signal processing 7 over exits 48 . 49 using a switch unit 47 an audio signal 8th on the left channel 14 and on the right channel 15 is forwarded. Alternatively, in an optional embodiment, also by the dynamics processor 5 via an exit 20 and 50 an audio signal are forwarded, which is also to the switch unit 47 is carried out. By means of the switch unit 47 is it possible to have both the outputs 48 . 49 or the outputs 20 . 50 on the left channel 14 and the right channel 15 further switch. In the 4 Everything is shown in relation to a frequency band, but also here, for example, including an existing equalizer 10 a corresponding extension or addition is made by the further wiring. For the sake of understanding, it is again pointed out that a frequency band only reproduces a part of the frequency spectrum.

The execution for only one channel, ie a mono-execution can in a preferred embodiment of 5 be removed. This illustration here is in connection with a signal processing 7 or a processing unit. The possible individual parameters are shown here and their processing is described. Via an audio input 1 becomes the audio signal 9 to the bandpass / the level determination 2 . 3 delivered. Also, the frequency 16 and the bandwidth 17 as well as a static gain 18 the bandpass / level determination 2 . 3 fed. The output of the level determination, namely the level information 43 , becomes a subtractor 23 fed. Also receives the subtractor 23 the threshold 28 , The output of the subtractor 23 is called difference signal 41 in, in the representation of 5 as two dynamics processors 5 shown blocks, led. It should be noted that also a processor 5 instead of two can be used. Like us the static gain 18 still to the dynamics processors 5 forwarded. As further parameters receive the dynamics processors 5 the ratio 29 as well as the settling time 26 next to the decay time 27 and the sign + or - of the dynamic gain 22 , From this count the dynamics processor (s) 5 Specifications outputs 46 pointing to a switcher 25 be guided. An exit 51 of the switch 25 gets to another switch 24 forwarded, which is also the static gain 18 is supplied. Finally, by switching the switch 24 either the static gain 18 or the exit 51 from the parameter outputs 46 results in an exit 52 be switched through, where the dynamic gain 19 then rests. While within the subtractor 23 The nominal difference between the level and the threshold is formed in one of the dynamics processors 5 the threshold is then processed if it falls below and in the other, the threshold processed when it is exceeded. This causes that over the respective exits 46 appropriate parameters to the switch 25 to be delivered.

A possible embodiment of a dynamics processor 5 give the 6 again. As inputs are the static gain 18 , the sign of dynamic gain 22 , with the signs + and -, the ratio 29 , the difference signal 41 as well as the settling time 26 and the decay time 27 specified as inputs.

From the settling time 26 and the decay time 27 is in a computing stage 38 with the addition of the difference signal 41 a Schellwert- and level calculation made. The output of the computing stage 38 becomes a switch 32 fed. Further, the switch 32 the parameter signal of the difference signal with the interposition of a limiter 38 fed. In addition lies also an exit 39 of the switch 32 on an input of the computing stage 31 , The desk 32 Thus, it is possible to switch between the ratio, the difference signal and the settling and settling time, namely the threshold value of the level, and this information to a computing stage 31 over a connection 39 hand off. At the switch 36 is the parameter of the static gain 18 at. The reference sign designated by +/- and as dynamic gain 22 lies as a parameter at a multiplier 33 next to the rule ratio 29 from the right stage 31 at. The output of the multiplier 33 goes to an addition level 34 in the static gain 18 with the result of the dynamic gain from the multiplier 33 is added. This result is sent to a limiter 35 forwarded, whose output also on the switch 36 goes. This finally comes from the entire parameter processing of the dynamics processor 5 resulting calculation result 37 is a result resulting from the gain / attenuation, the static gain and the dynamic gain.

With the diagram of 8th For example, the result which the invention provides can be made clear from the foregoing description. While the static gain as an audio signal 40 over the bandwidth 17 is shown as a curve, when activated, for example, by an excess of the threshold by one dB, a processed audio signal 13 as a result of processing by the dynamics processor 5 come out. This makes it clear that there is a level change below the static gain 18 lies.

With even larger changes in the threshold, there will be a greater change in the dynamic audio signal curve 13 opposite to the audio signal 40 in the 9 come at a ratio of 1: 2 and a threshold of -40 dB.

It becomes clear that the dynamics processor 5 the parameters of signal processing 7 or the processing unit controls. At the same time, the dynamics processor calculates 5 the dynamic gain 19 depending on the set input parameters. In a bandpass, the frequency and quality are used to calculate the cut-off frequencies for simple high and low pass filters, thus creating a bandpass. If the individual bands of a static equalizer are high-pass or low-pass filters, the cut-off frequency can also be modulated instead of gain.

alternative would be a change in the stroke of the user parameters. This value would be taken into account from the settling time and the decay time as times for Fading in and out adds to the static gain. In such a Case a dynamic gain is not calculated. This would mean that instead of the parameter ratio the parameters Hub and Step over / Below. This would use Above / Below whether the stroke is above or below the threshold value is added to the static gain.

Of the used in the preceding description is "fed" to be understood as an electrical connection, at z. B. digital Values are transferred or forwarded.

For Each frequency band can be a separate non-volatile memory to be available.

The Programs for processing the audio signal and the changeable parameters are changeable and interchangeable.

The Description of the present invention is applicable to all areas of Processing of audio signals applicable, especially in the sound processing from movies, music or the like.

1

Audio input

2

bandpass

3

level determination

4

additional interface

5

Dynamic Processor

6

delay

7

signal processing

8th

Audio output

9

audio signal

10

processing unit

11

existing interface

12

signal processing

13

edited audio signal

14

channel

15

channel

16

frequency

17

bandwidth

18

static Gain (reinforcement)

19

dynamic gain

20

output

21

parameters output

22

plus- and minus-dynamic gain

23

differentiator

24

switch

25

switch

26

settling

27

decay

28

threshold

29

reason (Control ratio)

30

limiter

31

calculating stage

32

switch

33

multiplier

34

addition

35

limiter

36

connection

37

calculation result

38

calculating stage

39

conversion

40

revised Signal of the frequency range

41

difference signal

42

Interface output

43

level information

44

parameter information

45

parameter input

46

parameters output

47

switch unit

48

output

49

output

50

output

51

output

52

output

53

frequency

54

frequency response

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 1282722 [0002]
• - DE 69804096 T2 [0003]
• - DE 10207200 A1 [0004]
• DE 19720217 A1 [0005]
• - DE 69130528 [0006]
• DE 102008023919 A1 [0007]

Claims (8)

Device for modifying an audio signal over its frequency range within at least one frequency band, essentially consisting of a processing unit ( 10 ) with an interface ( 11 ), the processing unit ( 10 ) a signal processing ( 7 ) containing an audio signal ( 9 ), characterized in that the signal processing ( 7 ) the audio signal ( 9 ) and that at least one further interface ( 4 ) is present, by means of the default parameter ( 21 ) can be changed and entered individually in their absolute value, whereby an interface output ( 42 ) a dynamics processor ( 5 ) whose changed controlled variables are also used for signal processing ( 7 ) and that at the audio output ( 8th ) the signal processing ( 7 ) a processed audio signal ( 13 ) is present. Device for modifying an audio signal over its frequency range within at least one frequency band, essentially consisting of a processing unit ( 10 ), wherein the processing unit a signal processing ( 7 ) containing an audio signal ( 9 ), characterized in that the signal processing ( 7 ) the audio signal ( 9 ) via a delay unit ( 6 ), and that at least one interface ( 4 ) is present, by means of the default parameter ( 21 ) can be changed and entered individually in their absolute value, whereby an interface output ( 42 ) a dynamics processor ( 5 ) whose changed controlled variables are also used for signal processing ( 7 ) and that at the audio output ( 8th ) the signal processing ( 7 ) a processed audio signal ( 13 ) is present. Device according to claim 1 or 2, characterized in that the audio signal ( 9 ) next to the delay device ( 6 ) a bandpass ( 2 ) and / or a level determination ( 3 ), which is also connected to the interface output ( 42 ) and that the output of the bandpass ( 2 ) and / or the level determination ( 3 ) as parameter output ( 21 ) with an input of the dynamics processor ( 5 ) connected is. Device according to one or more of the preceding claims, characterized in that the signal processing ( 7 ) is designed as an equalizer. Device according to one or more of the preceding Claims, characterized in that the equalizer as parametric or dynamic or static or multiple band or digital or analog or graphic equalizer or the like is executed. Device according to one or more of the preceding claims, characterized in that in at least one nonvolatile memory for the dynamic processor ( 5 ) at least one program for processing the parameters for changing the audio signal ( 9 ) is stored. Device according to one or more of the preceding Claims, characterized in that for each Frequency band a separate, non-volatile memory available is. Device according to one or more of the preceding claims, characterized in that the dynamic processor ( 5 ) with the interface ( 4 ) is connected directly or indirectly and the processed static and dynamic parameters of the signal processing ( 7 ).