DE102017117096A1 - Audio limiter - Google Patents

Abstract

Limiting the volume of audio systems in discotheques or at concerts may lead to unpleasant perception by the visitors.
The invention relates to an audio limiter (10) comprising: an amplifier unit (14, 15) adapted to control the power of at least one audio signal (24, 26) using a control variable (SG, SG '); in which
a power calculation unit (12, 33) configured to determine persistent sound level values (LEQ_L, LEQ_M, LEQ_S);
a control variable calculation unit (43) which is designed, using at least one reference value (LEQ_N, LEQ_N '), a first continuous sound level value (LEQ_REF, LEQ_L) and at least one second continuous sound level value (LEQ_M, LEQ_S), the control variable (SG, SG ').

Description

The invention relates to an audio limiter, a method for adjusting the gain of an amplifier unit, a corresponding computer-readable storage medium and an audio system.

Audio limiters are devices that down-convert the output level of an audio signal to a specific value in audio systems. Audio limiters are z. B. in discotheques or at concerts used to meet the legal requirements regarding a maximum allowable acoustic emission electroacoustic systems, hereinafter referred to simply as "volume" to meet.

The legal requirements are usually expressed by an equivalent continuous sound level. An equivalent continuous sound level is a sound pressure level averaged over a measuring time. Legal requirements usually include a measuring time of 5 to 60 minutes. A disco must therefore, when the maximum allowable value is exceeded, reduce the volume of the music played.

The DE 197 45 949 A1 describes a device of the type mentioned, in which the exceeding of a threshold level triggers a control, so that the volume of a speaker assembly is reduced.

However, the device described above has the disadvantage that the control becomes active only when the limit level is exceeded. However, this leads to an abrupt and possibly strong change of the volume in a room. This is perceived by visitors as disturbing and is not desired. In one case, such a regulation can even lead to the music having to be completely switched off or greatly reduced for a short period of time.

Starting from the described prior art, it is an object of the present invention to provide an audio limiter, a method for adjusting the gain of an amplifier unit, a computer-readable storage medium and an audio system, which addresses the disadvantages described above. In particular, an audio limiter should be specified, which is not perceived as disturbing or not at all for visitors of discotheques or concerts.

• eine Verstärkereinheit, die dazu ausgebildet ist, die Leistung mindestens eines Audiosignals unter Verwendung einer Steuergröße zu steuern;
• eine Leistungs-Berechnungseinheit, die dazu ausgebildet ist, Dauerschallpegelwerte, insbesondere äquivalente Dauerschallpegelwerte, zu bestimmen; und
• eine Steuergrößen-Berechnungseinheit, die dazu ausgebildet ist, unter Verwendung mindestens eines Referenzwerts, eines ersten Dauerschallpegelwerts und mindestens eines zweiten Dauerschallpegelwerts, die Steuergröße zu bestimmen.

The object is achieved by an audio limiter according to claim 1. In particular, the object is achieved by an audio limiter, which has the following:

• an amplifier unit configured to control the power of at least one audio signal using a control quantity;
• a power calculation unit configured to determine continuous sound level values, in particular equivalent continuous sound level values; and
• a control quantity calculation unit configured to determine the control quantity using at least one reference value, a first continuous sound level value, and at least one second continuous sound level value.

A core of the invention is that a control variable is determined by the use of at least two continuous sound level values. As a result, the control variable can be finely determined and there are no strong jumps in the determination of the control variable. Overall, this allows a more uniform amplifier behavior.

The amplifier unit may be configured to either amplify or attenuate an input signal.

In one embodiment, the first continuous sound level value may be determined over a first time interval and the second continuous sound level value determined over a second time interval, wherein the first time interval may be longer than the second time interval. In particular, the longer time interval may be 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 100%, 200%, 300%, 500% or 1000% longer than the shorter time interval.

In one embodiment, a continuous sound level value is determined by integration over time. In one embodiment, the first time interval may be determined over 60 minutes or over 10 minutes.

So there is always information about the continuous sound level value of the last 60 or 10 minutes before. In addition, the second time interval may be 5 minutes, so that for the calculation of the control variable on the one hand, a continuous sound level value over the last 60 or 10 minutes is taken into account and a continuous sound level value over the last 5 minutes. In the case where the legal requirements were fully met in the first time interval, necessary changes resulting from the second time interval may be less severe. However, if the statutory requirements have already been exceeded in the first time interval, then the changes in the control variable must be stronger. Of course, it is possible to use more than two continuous sound level values. Preferably, three continuous sound level values are taken into account, the time intervals corresponding to 10 minutes, 5 minutes and / or 10 seconds. More preferably, four continuous sound level values are taken into account, the time intervals corresponding to 10 minutes, 5 minutes, 10 seconds and / or 2 seconds.

Overall, by using a longer time interval and a shorter time interval, it can be achieved that the gradient of the gain is substantially smooth, i. without jumps, runs.

In an embodiment, the control quantity calculation unit may be designed to determine the control variable by multiplying a number of steps by a stepper value.

The Schrittgeberwert can z. B. be constant and stored in a configuration file. The calculation of the control quantity is simplified as a whole if only a number of steps has to be calculated, which is multiplied by the stepper value. This makes a very simple implementation possible.

In one embodiment, the audio limiter may include a power processing unit that may be configured to calculate a difference value from the difference of the at least one reference value and at least one persistent sound level value and determine the step count using the difference value.

In one embodiment, the power processing unit may be configured to select a set of candidate step count values in response to the first continuous sound level value, and to select a step count from the set of candidate step count values in response to the second continuous sound level value.

The embodiment described above may also be performed staggered with more than two continuous sound level values. At each level, the amount of candidate step counts may be reduced until a step count is selected.

By the serial restriction of the amount of candidate step number values, the number of steps necessary can be determined such that the continuous sound level values of different time intervals are taken into account. This can prevent unnecessary jumps in the volume. Furthermore, the volume can be adjusted early so that limits are not exceeded.

In one embodiment, the control quantity calculation unit may be configured to determine at least one dynamic reference value, wherein the power processing unit may be configured to calculate a difference value from the difference of the at least one dynamic reference value and at least one continuous sound level value and using the Difference value determines the number of steps to.

The reference value can therefore also be adapted dynamically. The embodiment described allows an increased volume to be allowed for a short time. Thus, increased flexibility is achieved.

In one embodiment, the dynamic reference value may be within a tolerance interval about the at least one reference value, wherein the tolerance interval may be formed in dependence on a difference of the first continuous sound level value and the reference value.

It is particularly advantageous if, as described above, the dynamic reference value lies within a tolerance interval around the reference value. This makes it possible to allow deviations from the reference value only in a certain range. In particular, the tolerance interval may be defined such that the limits of the interval are 1%, 2%, 3%, 5% or 10% of the reference value away from the reference value, preferably symmetrically.

In one embodiment, the amplifier unit may be formed as a digital amplifier unit and / or as an analog amplifier unit, wherein the audio signal may be formed as an analog audio signal or a digital audio signal, wherein the control variable may be designed to amplify the digital or analog Adjust the amplifier unit.

By the described embodiment, a high flexibility in the use of the described audio limiter is given.

In one embodiment, the power processing unit may be designed to determine the continuous sound level values cyclically, in particular with a frequency of> 0.1 hertz, preferably 1 hertz, particularly preferably 2 hertz.

The cyclic calculation of the continuous sound level values has the advantage that there are always current continuous sound level values for calculating the number of steps. It has been found that a frequency of 1 hertz achieves particularly good results. However, it is also possible that the continuous sound level values are calculated with different frequency. For example, a frequency of 0.1 hertz may be set for the first continuous sound level value and a frequency of 1 hertz for the second continuous sound level value. This saves computing resources. Furthermore, the calculation of the number of steps can be carried out with its own frequency. Also, the frequency for calculating the number of steps may correspond to the highest frequency of the continuous sound level values to be calculated.

In one embodiment, the audio limiter may comprise a communication device that may be configured to receive configuration data from a mobile and / or wired terminal, wherein the control variable calculation unit may be configured to include a frequency weight function for the continuous sound level value calculation, the at least one reference value and / or the step sensor value Use the configuration data. In one embodiment, the communication device is designed as a wireless communication device for wireless communication. Additionally or alternatively, the communication device can also be designed as a wired communication device.

In one embodiment, the audio limiter may implement a web server that may be provided via the communication device. Mobile terminals may in one embodiment, via the web server, control parameters, e.g. a frequency for continuous sound level value calculation, a measurement time for the continuous sound level evaluation calculation, interval limits of a tolerance interval, the at least one reference value and / or the pacer value to set, wherein the web server may be configured to supply the control parameters of the control variable calculation unit.

It is thus made possible that the essential parameters of the audio limiter can be specified by means of a (mobile) terminal comfortably by a user.

• - Empfangen eines Audiosignals;
• - Bestimmen eines ersten Dauerschallpegelwerts und mindestens eines zweiten Dauerschallpegelwerts für das Audiosignal;
• - Bestimmen einer Steuergröße unter Verwendung eines Referenzwerts, des ersten Dauerschallpegelwerts und des zweiten Dauerschallpegelwerts;
• - Einstellen der Verstärkung der Verstärkereinheit unter Verwendung der Steuergröße.

The object is further achieved by a method for adjusting the gain of an amplifier unit according to claim 11. In particular, the object is achieved by a method for adjusting the gain of an amplifier unit, in particular an amplifier unit of an audio limiter, as described above, comprising:

• - receiving an audio signal;
• Determining a first continuous sound level value and at least one second continuous sound level value for the audio signal;
• Determining a control quantity using a reference value, the first continuous sound level value and the second continuous sound level value;
• - Adjust the gain of the amplifier unit using the control quantity.

There are similar or identical advantages as have already been described in connection with the audio limiter described above.

• - Bestimmen mindestens eines dynamischen Referenzwerts;
• - Berechnen eines Differenzwerts aus der Differenz von dem mindestens einen dynamischen Referenzwert und mindestens einem Dauerschallpegelwert;
• - Bestimmen der Schrittanzahl unter Verwendung des Differenzwerts.

In one embodiment, the method may include:

• - Determining at least one dynamic reference value;
• Calculating a difference value from the difference of the at least one dynamic reference value and at least one continuous sound level value;
• Determining the number of steps using the difference value.

In one embodiment, the method may include determining a tolerance interval around the at least one reference value in response to a difference between the first continuous sound level value and the reference value, wherein the dynamic dynamic reference value may be determined to be within the tolerance interval.

In one embodiment, the method may include selecting a set of candidate step count values in response to the first continuous sound level value and selecting a step count from the set of candidate step count values in response to the second continuous sound level value.

In one embodiment, the control variable can be determined by multiplying a number of steps by a, in particular constant, stepper value.

• - Berechnen der Differenz von mindestens einem Referenzwert und mindestens einem Dauerschallpegelwert;
• - Bestimmen der Schrittanzahl unter Verwendung des Differenzwerts.

In one embodiment, the method may include:

• Calculating the difference of at least one reference value and at least one continuous sound level value;
• Determining the number of steps using the difference value.

There are similar or identical advantages as have already been described in connection with the audio limiter.

The object is further achieved by a computer-readable storage medium according to claim 17. More specifically, the object is achieved by a computer-readable storage medium containing instructions that cause at least one processor to implement a method as described above when the instructions pass through running the processor.

• - einen Audiobegrenzer, wie er vorstehend beschrieben wurde;
• - mindestens eine Audio-Ausgabeeinrichtung, die kommunikativ mit dem Audiobegrenzer verbunden ist;
• - eine Audio-Aufnahmeeinrichtung, welche kommunikativ mit dem Audiobegrenzer verbunden ist, wobei
  • der Audiobegrenzer, die Audio-Aufnahmeeinrichtung und die mindestens eine Audio-Ausgabeeinrichtung zusammen einen Regelkreis zur Einstellung der Laustärker der mindestens einen Audio-Ausgabeeinrichtung bilden.

The object is further achieved by an audio system according to claim 18. In particular, the object is achieved by an audio system, comprising:

• an audio limiter as described above;
• at least one audio output device communicatively connected to the audio limiter;
• - An audio recording device which communicatively connected to the audio limiter, wherein
  • the audio limiter, the audio recording device and the at least one audio output device together form a control circuit for adjusting the noise intensity of the at least one audio output device.

The provision of a control loop ensures that the audio output device does not exceed the permitted volume.

Further embodiments emerge from the subclaims.

• 1 eine schematische Darstellung eines Audiosystems mit einem Audiobegrenzer;
• 2 eine schematische Darstellung eines Audiobegrenzers;
• 3 eine schematische Darstellung einer Leistungs-Berechnungseinheit;
• 4 eine schematische Darstellung der Auswahl von Kandidatenschrittanzahlwerte.

In the following the invention will be explained in more detail with reference to figures. Showing:

• 1 a schematic representation of an audio system with an audio limiter;
• 2 a schematic representation of an audio limiter;
• 3 a schematic representation of a power calculation unit;
• 4 a schematic representation of the selection of candidate step numbers.

1 shows a schematic representation of an audio system 1 , which has an audio source 7 has, the audio signals 8th to an audio limiter 10 emits. In the present case, it is the audio source 7 to a CD player. In other embodiments, the audio source may be 7 For example, as a laptop, as a mixer or as a mobile device, such as a smartphone or tablet, be formed.

At the audio limiter 10 is a microphone 2 connected, which audio signals 8 '"to the audio limiter 10 emits. The audio limiter 10 has in the embodiment shown an LCD display 11 , on the current characteristics of the audio limiter 10 displayed, such as the current gain power. The audio limiter 10 of the embodiment shown is arranged in a metal housing, which can be installed in a 19 inch rack. Such racks are common in stage systems or in nightclubs. The LCD display 11 is merely optional, so in other embodiments no LCD display 11 can be provided.

Using the audio signal 8 "'and the audio signal 8th the audio source 7 , generates the audio limiter 10 an amplified audio signal 8th' , which an amplifier group or amplifier system 4 is supplied. The audio limiter 10 is thus formed as a preamplifier in the embodiment shown. The amplifier system 4 amplifies the audio signal 8th' continue and leads the further amplified audio signal 8th" the speaker 3 to. The speaker 3 gives the audio signal 8th" from. The components mentioned 2 . 10 . 4 and 3 So form a loop.

To configure the audio limiter 10 is a smartphone 5 provided, which via a touch screen 6 has a UI that can be displayed. The user interface is formed in the embodiment shown as a web page, which is provided by a web server, the audio limiter 10 is performed. The smartphone 5 and the audio limiter 10 communicate via a WLAN interface. In other embodiments, further wireless communication interfaces are conceivable, such. B. Bluetooth. In addition, it is also intended that the audio limiter 10 has an ethernet interface, allowing laptops and other computer devices to be wired with the audio limiter 10 can be connected. This is particularly advantageous in discotheques, since the provision of a constant and strong WLAN signal is difficult there.

The 2 shows a schematic representation of the audio limiter 10 , The audio limiter can receive audio signals 10 via an AES / EBU connection 17 , about the digital audio signals 24 to a digital amplifier unit 14 can be sent. The audio limiter has analogue processing 10 via analogue connections 18 . 18 ' , via which an analog audio input signal 26 an analog amplifier unit 15 can be supplied.

A microphone signal 23 can via a microphone connection 19 a power calculation unit 12 be supplied. The performance calculation unit 12 calculated from the microphone signal 23 and a reference value LEQ-N control quantities SG . SG ' , the analog amplifier unit 15 or according to the digital amplifier unit 14 be supplied. Using the control quantities SG . SG ' amplify or attenuate the amplifier units 14 . 15 the audio signals 24 . 26 and thus give amplified analog audio output signals 27 or digital audio output signals 25 via an AES / EBU connection 17 or analogue connections 18 . 18 ' from.

The audio limiter 10 also has a VGA connector 20 and an HDMI port 21 For connecting a monitor so that status data or warnings can be displayed via an external display. In addition, the audio limiter has 10 also via a built-in display 11 where important information can be output. Furthermore, the audio limiter includes 10 an Ethernet connection 22 that allows communication over a network. So can laptops and other computers with the audio limiter 10 get connected. Via the Ethernet connection 22 For example, configuration data may be used to set the parameters of the audio limiter 10 be transmitted.

In addition, the audio limiter includes 10 a log unit 13 that the function of the audio limiter 10 logged. The through the log facility 13 created logs can be via a USB interface 16 be retrieved. For example, the log files can be transferred to a USB stick. The logs are transmitted by control data 28 from the performance calculation unit 12 created. It is also provided that the log unit 13 Sound pressure level data stores and these on the control data 28 the performance calculation unit 12 provides. The logs can also be called up additionally or alternatively via the web server.

The 3 shows a schematic view of a power calculation unit 30 , The performance calculation unit 30 comprises a memory device 32 and a calculation device 33 , The calculation device 33 receives a microphone signal 31 and a reference value LEQ_N , Using the microphone signal 31 and the reference value LEQ_N generates the calculation device 33 control variables SG . SG ' which are used to control amplifier units 14 . 15 be used. The reference value LEQ_N can be preset manually by a user. This is in an alternative embodiment in the storage device 32 to a ROM, in which reference values LEQ_N are stored unchangeable from the factory. In a further embodiment, the reference value LEQ_N downloaded from an internet server. This ensures that there is always a current reference value LEQ_N is present. It is also possible to react to legal differences in different countries.

The 4 shows a schematic representation of how the control variable SG . SG ' is calculated. First, an audio signal 41 a power processing unit 42 fed. The power processing unit 42 also receives a long-term reference value LEQ_N indicating a maximum LEQ value for a time interval. In the embodiment shown, the time interval is the long-term reference value LEQ_N is assigned for 60 minutes. From the audio signal 41 calculates the power processing unit 42 a LEQ value LEQ_REF, ie an equivalent continuous sound level. The LEQ value averages the sound energy over the measurement duration. In the next step, the power processing unit compares 42 the calculated LEQ value LEQ_REF with the long term reference value LEQ_N , Of course, when calculating the LEQ value LEQ_REF, the same time interval is assumed as in the long term reference value LEQ_N , Based on the calculated difference from the long-term reference value LEQ_N and the calculated LEQ value LEQ_REF becomes a set of candidate step count values G1 to G5 selected.

LEQ_diff Kandidatenschrittanzahlwerte G1 LEQ_diff << 0 (weit drunter) {2, 1, 0, 0} G2 LEQ_diff < 0 (drunter) {2, 1, 0, 0} G3 LEQ_diff ≈ 0 (im Wesentlichen identisch) {0, 0, -1, -2} G4 LEQ_diff > 0 (drüber) {0, -2, -4, -5} G5 LEQ_diff >> 0 (stark drüber) {-2, -4, -8, -10} The selected set of candidate step counts indicates how much the calculated LEQ value LEQ_REF is from the long term reference value LEQ_N deviates, ie how much the regulation should intervene. In particular, the selected set of candidate step count values indicates whether the calculated LEQ value LEQ_REF is over the long term reference value LEQ_N or below the long term reference value LEQ_N lies. The following listing shows how the sets of candidate step counts G1 to G5 to the calculated difference between the calculated LEQ value LEQ_REF and the long-term reference value LEQ_N correspond, ie $$\text{LEQ\_diff}=\text{LEQ\_REF}-\text{LEQ\_N}$$

LEQ_diff Candidates step number values G1 LEQ_diff << 0 (far below) {2, 1, 0, 0} G2 LEQ_diff <0 (under) {2, 1, 0, 0} G3 LEQ_diff ≈ 0 (essentially identical) {0, 0, -1, -2} G4 LEQ_diff> 0 (over it) {0, -2, -4, -5} G5 LEQ_diff >> 0 (strong over it) {-2, -4, -8, -10}

In the exemplary embodiment shown, the calculated LEQ value LEQ_REF is below the long-term reference value LEQ_N such that the set of candidate step counts G2 is selected.

The long-term reference value LEQ_N corresponds in the illustrated embodiment, the legal requirements that are prescribed in a corresponding country. Due to the fact that the calculated LEQ value LEQ_REF is below the legal requirements, it is permissible to increase the gain further. To the long-term reference value LEQ_N Therefore, a tolerance interval is defined, whereby a basic reference value of the calculated difference LEQ_DIFF is a dynamic reference value LEQ_N ' is calculated, which lies in the tolerance interval. Due to the fact that the calculated LEQ value LEQ_REF is below the long-term reference value LEQ_N is the dynamic reference value LEQ_N ' above the long-term reference value LEQ_N lie. This means that the music may be played louder for a short time than it is over the whole, due to the long-term reference value LEQ_N expressed, time interval would be permissible.

In a next step (second step) becomes another LEQ value LEQ_L calculated. This additional LEQ value LEQ_L is preferably calculated over a shorter time interval, eg 5 or 10 minutes. Subsequently, the further LEQ value LEQ_L with the dynamic reference value LEQ_N ' compared. In the example of the upper table, only one more LEQ value is calculated. Based on the difference of the further LEQ value LEQ_L and the dynamic reference value LEQ_N ' becomes a step count F selected from the set of selected candidate step counts.

If more than two LEQ values are calculated, the group of candidate step counts will be constrained accordingly with each LEQ value.

The selected number of steps F is from a control quantity calculation unit 43 multiplied by a step value, where the result of the multiplication is the control quantity SG . SG ' indicates. The step value is a constant used by the user of the audio limiter 10 can be preset.

In a further embodiment, instead of comparing the calculated LEQ value LEQ_REF, the LEQ value LEQ_L in the first step with the long term reference value LEQ_N and in the next step, the LEQ value LEQ_M , eg determined in a time interval of 1 minute, or the LEQ value LEQ_S , eg determined in a time interval of 10 or 2 seconds, with the long-term reference value LEQ_N compared. The LEQ value LEQ_L can be determined over 10 minutes. This embodiment can be applied even if the legal requirement is actually the long-term reference value LEQ_N for a much longer period of time, eg 60 minutes, pretends. Due to the algorithm according to the invention, the specification is always maintained in the short time interval, for example the 10 minutes, so that no exceeding of the limit value can occur even in the longer time interval. The comparison in the first step with the LEQ value LEQ_L Calculated for a shorter time interval has the further advantage that the system responds more dynamically and intervenes much more "smoothly".

According to the invention, it is also possible in more than two steps for further LEQ values, for example the LEQ value LEQ_S , and with the long-term reference value LEQ_N or the long term dynamic reference value LEQ_N ' to compare. It can also have different long-term reference value LEQ_N or dynamic long-term reference value LEQ_N ' be used to perform the comparison in the individual steps, in particular in the first and / or second step.

The term continuous sound level may also denote an averaged power value or energy value that is constant over a measurement interval, e.g. the said 60 minutes or 10 minutes or 1 minute or 10 seconds or 2 seconds are averaged.

LIST OF REFERENCE NUMBERS

1

Audio system

2

microphone

3

speaker

4

sound system

5

mobile device / smartphone

6

user interface

7

Audio source / CD player / mixer

8, 8 ', 8 ", 8'"

audio signal

9

control signal

10

Audio limiter

11

Display / Display

12, 30

Power calculation unit

13

Log unit

14

digital amplifier unit

15

analog amplifier unit

16

USB port

17

AES / EBU connection

18, 18 '

L / R-analog connection

19

microphone connector

20

VGA port

21

HDMI port

22

Ethernet port

23, 31

microphone signal

24

digital audio input signal

25

digital audio output

26

analog audio input signal

27

digital audio output

28

control data

32

memory device

33

calculator

41

audio signal

42

Performance processing unit

43

Control amount calculation unit

LEQ_N

Long-term reference value

LEQ_N '

dynamic long-term reference value

LEQ_L,

LEQ value

LEQ_M,

LEQ value

LEQ_S

LEQ value

F

step number

G1-G5

Amount of candidate step counts

SG, SG '

control variable

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19745949 A1 [0004]

Claims (18)

Audio limiter (10), comprising: an amplifier unit (14, 15) configured to control the power of at least one audio signal (24, 26) using a control variable (SG, SG '); characterized by - a power calculating unit (12, 33) configured to determine persistent sound level values (LEQ_REF, LEQ_L, LEQ_M, LEQ_S); a control variable calculation unit (43) which is designed, using at least one reference value (LEQ_N, LEQ_N '), a first continuous sound level value (LEQ_REF, LEQ_L) and at least one second continuous sound level value (LEQ_M, LEQ_S), the control variable (SG, SG '). Audio Limiter (10) after Claim 1 , characterized in that the first continuous sound level value (LEQ_REF, LEQ_L) is determined over a first time interval, in particular 60 minutes or 10 minutes, and the second continuous sound level value (LEQ_M, LEQ_S) over a second time interval, in particular of 5 minutes, 1 minute, 10 Seconds or 2 seconds, with the first time interval being longer than the second time interval. Audio limiter (10) according to any one of the preceding claims, characterized in that the control variable calculation unit (43) is adapted to determine the control variable (SG, SG ') by multiplying a number of steps (F) with a, in particular constant, encoder value. Audio limiter (10) according to one of the preceding claims, characterized by a power processing unit (42) which is formed from the difference between the at least one reference value (LEQ_N, LEQ_N ') and at least one continuous sound level value (LEQ_REF, LEQ_L, LEQ_M, LEQ_S) to calculate a difference value and to determine the number of steps (F) using the difference value. Audio limiter (10) according to one of the preceding claims, characterized in that the control variable calculation unit (43) is adapted to determine at least one dynamic reference value (LEQ_N '), wherein the power processing unit (42) is adapted to derive from the difference calculate a difference value from the at least one dynamic reference value (LEQ_N ') and at least one continuous sound level value (LEQ_REF, LEQ_L, LEQ_M, LEQ_S) and determine the number of steps (F) using the difference value. Audio limiter (10) according to one of the preceding claims, in particular according to Claim 5 characterized in that the dynamic reference value (LEQ_N ') lies within a tolerance interval around the at least one reference value (LEQ_N), wherein the tolerance interval is formed as a function of a difference between the first continuous sound level value (LEQ_REF, LEQ_L) and the reference value (LEQ_N) , Audio limiter (10) according to one of the preceding claims, in particular according to Claim 4 characterized in that the power processing unit (42) is adapted to select a set of candidate step count values in response to the first continuous sound level value (LEQ_REF, LEQ_L) and a step count (F) in response to the second continuous sound level value (LEQ_M, LEQ_S) the amount of candidate step counts. Audio limiter (10) according to one of the preceding claims, characterized in that the amplifier unit (14, 15) as a digital amplifier unit (14) and / or as an analog amplifier unit (15) is formed, wherein the audio signal (24, 26) as an analog audio signal (26) or a digital audio signal (24) is formed, wherein the control variable (SG, SG ') is adapted to adjust the gain of the digital or analog amplifier unit (14, 15). Audio limiter (10) according to one of the preceding claims, characterized in that the power calculation unit (12, 33) is designed to determine the continuous sound level values (LEQ_REF, LEQ_L, LEQ_M, LEQ_S) cyclically, in particular with a frequency greater than 0, 1Hz, preferably 1Hz, more preferably 2Hz. Audio limiter (10) according to one of the preceding claims, characterized by a wireless communication device, which is designed to receive configuration data from a mobile terminal (5), wherein the control variable calculation unit (12, 43) is adapted to a frequency for Continuous sound level calculation, the at least one reference value (LEQ_N, LEQ_N ') and / or the pacemaker value using the configuration data. Method for adjusting the gain of an amplifier unit (14, 15), in particular an amplifier unit (14, 15) of an audio limiter (10) according to one of the preceding claims, comprising: - receiving an audio signal (23); - determining a first continuous sound level value (LEQ_REF, LEQ_L) and a second continuous sound level value (LEQ_M, LEQ_S) for the audio signal (23); - determining a control quantity (SG, SG ') using a reference value, the first continuous sound level value (LEQ_REF, LEQ_L) and the second continuous sound level value (LEQ_M, LEQ_S); - Adjusting the gain of the amplifier unit (14, 15) using the control variable (SG, SG '). Method according to Claim 11 characterized by - determining at least one dynamic reference value (LEQ_N '); Calculating a difference value from the difference of the at least one dynamic reference value (LEQ_N ') and at least one continuous sound level value (LEQ_REF, LEQ_L, LEQ_M, LEQ_S); Determining the number of steps (F) using the difference value. Method according to one of Claims 11 or 12 , especially after Claim 12 , characterized by determining a tolerance interval around the at least one reference value (LEQ_N) in response to a difference from the first continuous sound level value (LEQ_REF, LEQ_L) and the reference value (LEQ_N), wherein the dynamic reference value (LEQ_N ') is determined to be within the tolerance interval becomes. Method according to one of Claims 11 to 13 Characterized by - selecting a set of candidates step number values in response to the first continuous noise value (LEQ_REF, LEQ_L), and - selecting a number of steps (F) from the set of candidates step number values in response to the second continuous noise value (LEQ_M, LEQ_S). Method according to one of Claims 11 to 14 , characterized in that the control variable (SG, SG ') by multiplying a number of steps (F) with a, in particular constant, encoder value is determined. Method according to one of Claims 11 to 15 characterized by - calculating the difference of at least one reference value (LEQ_N, LEQ_N ') and at least one continuous sound level value (LEQ_M, LEQ_S); Determining the number of steps (F) using the difference value. A computer-readable storage medium containing instructions that cause at least one processor to perform a method according to any one of Claims 11 - 16 to implement when the instructions are executed by the processor. Audio system (1), comprising: - an audio limiter (10) according to one of Claims 1 to 10 ; - at least one audio output device (3) communicatively connected to the audio limiter (10); - an audio recording device (2) communicatively connected to the audio limiter (10); characterized in that the audio limiter (10), the audio recording device (2) and the at least one audio output device (3) together form a control circuit for adjusting the volume of the at least one audio output device (3).

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