JPH0830271A - Effector - Google Patents

Abstract

PURPOSE:To enable reducing a sound-cutting at the time of changing a parameter by judging whether a parameter changing is associated with the changing of a delay time or not and determining whether a musical sound signal to which an effect is imparted is muted or not. CONSTITUTION:When the parameter changing of a filter 1 is linked to a noise generation, a multiplier B controls only the signal of the filter 1 by making a muliplication coefficient small. When the parameter changing of the filter 1 is not linked to the noise generation, the multiplier B does not control the wet signal and the dry signal of the filter 1. An adder 2 adds a signal made to be the coefficient multiple of the output signal of the filter 1 by the multiplier B and a signal made to be the coefficient multiple of an input signal by a multiplier A. When the parameter changing of a reverb 3 is linked to the noise generation, a multiplier D suppresses the signal of a reverberant sound of the reverb 3. An adder 4 adds the wet signal of the multiplier D and the signal of a multiplier C to make them an output signal.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an effector for imparting various effects to a musical sound.

[0002]

2. Description of the Related Art A musical sound electric signal generated by playing an electric musical instrument such as an electric guitar or an electronic musical instrument is given various effects by passing through an effector. The effects include distortion for distorting sound and reverb for adding reverberation effect.

While playing an electric guitar, the parameters of the effector may be changed on the way to change the atmosphere of the performance. By changing the parameters, for example, the reverberation effect can be made deeper or shallower. However, if the parameters are changed during the performance, noise may occur depending on the type of the parameters. Since such noise is offensive to the listener, the following measures are taken.

FIG. 16 shows a configuration example of a conventional effector. The effector is a filter 51 and a reverb 54.
You can add one effect. The signal input to the effector is input to the filter 51 and the multiplier 52. The filter 51 passes only a predetermined frequency component with respect to the input signal. The adder 53 is a filter 51.
And the frequency component filtered by
The signal obtained by multiplying the input signal by the coefficient is added by. By changing the parameter of the filter 51 or the multiplication coefficient of the multiplier 52, it is possible to generate, for example, a tone color having many high frequency components and low frequency components.

The output signal of the adder 53 is input to the reverb 54 and the multiplier 55. The reverb 54 produces a reverberant sound. The adder 56 adds the reverberant sound generated by the reverb 54 and the signal obtained by multiplying the output signal of the adder 53 by the coefficient by the multiplier 55. By changing the parameter of the reverb 54 or the multiplication coefficient of the multiplier 55, the reverberation characteristic and the reverberation depth can be changed.

The multiplier 57 is provided to prevent noise generated by changing the parameters of the filter 51 or the reverb 54. The multiplier 57 outputs the output signal of the adder 56 as it is when the filtering or the reverb is performed without changing the parameter. When the parameter of the filter 51 or the reverb 54 is changed, the multiplication coefficient of the multiplier 57 is reduced to suppress the output level.

FIG. 17 is a graph showing changes in output level when parameters are changed. When reverberation is generated by the reverb, the output level decreases as time passes. It is assumed that the parameter is changed at time t1 when the output level is decreasing.

At time t1, when the reverb parameter is changed or the filter parameter is changed, the output level is suppressed and the noise is prevented. However, when the output level is suppressed, the reverberation sound and the like are not output, so that the sound feels like it is cut off. If the parameters are not changed, the output level is attenuated at a constant speed as shown by the dotted line in the figure.

[0009]

If the parameter is changed in any one of the effectors, the output of the sound effect generated by the effector is suppressed. But,
Not all types of parameter changes lead to noise generation. Therefore, if the output of the sound effect can be suppressed only when the parameter that causes the generation of noise is changed, it is possible to reduce the feeling of sound interruption due to the parameter change.

An object of the present invention is to provide an effector capable of reducing sound breaks when changing parameters.

[0011]

The effector of the present invention comprises:
Effect imparting means for imparting an effect to a tone signal supplied from the outside, instructing means for instructing to change a parameter of an effect imparted by the effect imparting means, and change instruction by the instructing means for changing the delay time in the effect imparting means. If the parameter checking means determines that the delay time is to be changed, the effect applying means mutes and outputs the musical tone signal to which the effect is applied to change the delay time. If not, the effect imparting means has an output means for outputting the musical tone signal to which the effect is imparted without muting.

[0012]

When the parameter of the effect added to the musical tone signal is instructed to be changed, it is judged whether or not the musical tone signal to which the effect is added is muted by judging whether or not the parameter change is related to the change of the delay time. Decide whether or not If it is related to the change of the delay time, noise is likely to occur due to the parameter change, so the effect is added to the musical tone signal being muted, and if it is not related to the change of the delay time, noise is less likely to occur Does not mute the tone signal to which is added.

[0013]

FIG. 14 is a block diagram showing the structure of an effector device according to an embodiment of the present invention. The tone signal input to the effector device is supplied to the A / D converter 21. The A / D converter 21 converts a musical tone analog signal into a musical tone digital signal. The converted tone digital signal is supplied to a digital signal processor (DSP) 22.

The DSP 22 is capable of imparting a plurality of types of effects such as delay and reverb according to a control signal from the CPU 27. In addition, DSP22,
An effect is added to the musical tone digital signal by performing an operation using a buffer or the like provided in the RAM 23. The musical tone signal to which the effect is added is generated by the sound system 24.

Parameter change for changing the effect by the effector is performed by the panel 28 or the MIDI interface 29. The panel 28 has a switch for changing parameters, and can change the reverberation characteristic and the depth of the reverberation effect, for example. The MIDI interface 29 can be connected to an external MIDI device. The external MIDI device can instruct the MIDI interface 29 to change the parameter by the MIDI signal. CPU 27 is a panel 28 or MIDI
A parameter change event is detected from the interface 29, and the parameter instructed to be changed is supplied to the DSP 22.

The CPU 27 determines whether or not the parameter change leads to noise generation. If the parameter change leads to noise generation, the sound effect generated in the DSP 22 is suppressed. If the parameter change does not lead to noise generation, the parameter inside the DSP 22 is changed by the interpolation function without suppressing the sound effect. Change gradually.

The ROM 25 stores a calculation program. The CPU 27 is a RAM according to this arithmetic program.
Various arithmetic processes are performed using a working memory such as a register and a buffer memory provided in the unit 26. CPU27
Controls the ROM 25, the RAM 26, the panel 28, the MIDI interface 29, and the DSP 22 via the bus 30.

FIG. 15 is a schematic diagram showing the contents of the parameter table provided in the RAM 26 of FIG. The effector can add a plurality of effects such as delay and reverb. The operator can instruct a delay such as a delay time of 100 or 80 from the panel or the like. Further, the depth of the reverb can be designated by selecting the reverb type such as a hall or a room.

The parameter table stores effector parameters. For example, the table has Nos. 1 to 10, and parameters such as a delay time of 100 in No. 1 and a reverb type of hall (reverberation time of 10 in No. 2) are stored.

When a parameter change is instructed by the panel or the MIDI interface, it is compared with the DSP parameters stored in the parameter table to determine whether or not the parameter change causes noise. If the parameter is changed to generate noise, the sound effect generated in the DSP is suppressed. If the parameter does not generate noise, the sound effect is not suppressed.

FIG. 1 shows a configuration example of two effectors, a filter and a reverb, which are constituted by a DSP. DS
The signal input to P is input to the filter 1 and the multiplier A in parallel. The filter 1 passes only a predetermined frequency component of the input signal. By changing the parameter of the filter 1 or the coefficient of the multiplier A, it is possible to generate a tone color having a high frequency component or a low frequency component.

If the parameter change of the filter 1 leads to noise generation, the multiplier B reduces the multiplication coefficient to suppress only the signal (wet signal) filtered by the filter 1. The output signal (dry signal) of the multiplier A that bypasses the filter 1 is not suppressed. On the other hand, if the parameter change of the filter 1 does not lead to noise generation, neither the wet signal nor the dry signal of the filter 1 is suppressed. The adder 2 adds the signal obtained by multiplying the output signal of the filter 1 by the multiplier B and the signal obtained by multiplying the input signal by the multiplier A to each other.

The output signal of the adder 2 is input to the reverb 3 and the multiplier C in parallel. The reverb 3 produces a reverberant sound. By changing the parameter of the reverb 3 or the coefficient of the multiplier C, the depth of reverberation can be changed. If the parameter change of the reverb 3 leads to noise generation, the multiplier D reduces the multiplication coefficient to suppress the reverberant sound signal (wet signal) generated by the reverb 3. The output signal (dry signal) of the multiplier C bypassing the reverb 3 is not suppressed. On the other hand, if the parameter change of the reverb 3 does not lead to noise generation, neither the wet signal nor the dry signal of the reverb 3 is suppressed.

The adder 4 adds the wet signal obtained by multiplying the output signal of the reverb 3 by the multiplier D and the signal obtained by multiplying the output signal of the adder 2 by the multiplier C. The signal added by the adder 4 becomes the output signal of the DSP,
The output signal is sounded in the sound system.

Among the plurality of parameters forming the filter 1 and the reverb 3, there are some that lead to noise generation and some that do not lead to noise generation. As the cause of noise,
In the case of filter 1, changing the cutoff frequency may cause the filter output waveform to become discontinuous,
In the case of reverb 3, it can be considered that the delay time of the delay line is changed by changing the reverberation characteristic and the reverb output waveform becomes discontinuous.

FIG. 2 shows a structural example of a processing circuit using a delay line. The input signal is supplied to the adder 5.
The adder 5 adds the input signal and the feedback signal supplied from the multiplier 7. The added signal is delayed by the delay line 6 and output from the line L1.
The delay signal output from the line L1 is multiplied by the coefficient by the multiplier 8 and output.

The output signal of the line L1 is the multiplier 7
Is multiplied by the coefficient and fed back to the adder 5. The fed-back signal and the new input signal are added by the adder 5 and delayed by the delay line 6. The delayed signal is multiplied by the coefficient by the multiplier 8 and becomes an output signal. Hereinafter, the delayed signal is repeatedly fed back to generate an output signal.

The parameters of this circuit include the delay time (L
1), the feedback amount (multiplier 7) and the output level (multiplier 8) are considered. When changing the parameters, changing the delay time leads to noise generation.
If the level (amplitude) is changed gradually, noise will not be generated.

The output of the delay line 6 is changed from the line L1 to the line L2 to shorten the delay time,
Since the change from 1 to the line L3 to increase the delay time leads to noise generation, it is necessary to suppress the wet signal such as reverb.

On the other hand, since changing the parameter such as changing the multiplication coefficient of the multiplier 7 to change the feedback amount or changing the multiplication coefficient of the multiplier 8 to change the output level does not lead to noise generation, reverb etc. There is no need to suppress the wet signal of.

Whether or not the change of each parameter leads to the occurrence of noise is determined by the calculation of the CPU. Next, a processing procedure when a filter parameter change or a reverb parameter change is instructed will be described.

FIG. 4 is a flow chart showing the processing when the filter parameters are changed. Filter 1 from Figure 1 from the panel or MIDI interface
When the parameter change is instructed, in step P1, the multiplication coefficient of the multiplier B of FIG. 1 is reduced to attenuate the wet signal of the filter 1 and mute.

In step P2, the parameters of the filter instructed to be changed by the DSP are reset and the parameters are changed. When parameter setting is completed, step P
In step 3, the multiplication coefficient of the multiplier B is returned to the original value to cancel the mute. This is the end of the filter parameter changing process.

Since the filter 1 of the present embodiment is of a type in which all kinds of parameter changes lead to noise generation, muting is always performed when there is any parameter change. When a filter that can be divided into ones that are not connected to ones is used, muting may be performed only when there is a parameter change that causes noise generation.

FIG. 5 is a flow chart showing the processing when the reverb parameter is changed. When the parameter change of the reverb 3 in FIG. 1 is instructed from the panel or the MIDI interface, in step Q1,
Check whether the parameter instructed to change is related to the delay time. Since the parameter of the current DSP is stored in the parameter table in the RAM of FIG. 15, it is checked whether or not the current delay time is different from the delay time instructed to be changed.

If the delay time is different, it will lead to noise generation. Therefore, the process proceeds to step Q2 and the multiplier D of FIG.
To attenuate the wet signal of the reverb 3 and mute. In step Q3, the delay time instructed to be changed is set in the DSP, and the parameters are changed. When the setting of the delay time is completed, in step Q4, the multiplication coefficient of the multiplier D is restored, the mute is released, and the process is completed.

If it is determined in step Q1 that the parameter change is other than the delay time (for example,
(No change in the feedback amount by the multiplier 7 or the output level by the multiplier 8 in FIG. 2) or noise is generated, so the process proceeds to step Q5, and the parameters are gradually changed using the interpolation function. The interpolation is performed, for example, in Japanese Patent Application No. 5-2.
It can be carried out by the method described in No. 91971. When the parameter change is completed, the process ends.

FIG. 3 is a graph showing the change of the output level when only the parameters of the filter of FIG. 1 are changed. Unless the wet signal of the reverb 3 is attenuated by the multiplier D of FIG. 1, the reverberation sound is attenuated over time, so that the output level is attenuated at a predetermined speed.

At time t1, when the parameter of the filter 1 of FIG. 1 is instructed to be changed, the wet signal is muted by the multiplier B. However, if the multiplication coefficient of the multiplier A is larger than 0, the dry signal is continuously output before and after the parameter change, so that the sound is not interrupted.

Even if the multiplication coefficient of the multiplier A is 0, the reverb 3 continues to output the output level at the predetermined attenuation speed without being muted, so that the sound suddenly occurs at the time t1. It never breaks.

Similarly, when the parameters of the reverb 3 of FIG. 1 are changed, the wet signal is only muted by the multiplier D in some cases, and if the multiplication coefficient of the multiplier C is larger than 0, the dry signal is reduced. The signal is output continuously, so there is no sudden interruption of sound.

Conventionally, even in the case of an effect program change in which only the parameters of the filter 51 of FIG. 16 are different, the output of both the filter 51 and the reverb 54 is muted by the multiplier 57, so that the sound is always output. It was broken. According to the present embodiment, it is possible to change the parameters without feeling the sound interruption.

FIG. 6 shows a configuration example of a multi-effector including five effectors. The effector can be realized using a DSP. With the advancement of DSP, it is possible to configure five different effectors in series for a tone signal. The five effectors are, for example, distortion, filter, chorus, delay and reverb.

The input signal to the multi-effector is divided into a wet signal whose sound is distorted by the distortion 11 and a dry signal whose coefficient is multiplied by the multiplier 11A. The multiplier 11B multiplies the wet signal output from the distortion 11 by a coefficient, and mutes the wet signal according to the type of parameter instructed to be changed. The adder 12 adds the dry signal output from the multiplier 11A and the wet signal output from the multiplier 11B to generate a distortion sound effect.

The output signal of the adder 12 is the filter 13
Is divided into a wet signal processed so as to have a predetermined frequency component and a dry signal multiplied by a coefficient by the multiplier 13A. The multiplier 13B multiplies the wet signal output from the filter 13 by a coefficient, and mutes the wet signal according to the type of parameter instructed to be changed. The adder 14 adds the dry signal output from the multiplier 13A and the wet signal output from the multiplier 13B to generate a sound effect of the filter.

The output signal of the adder 14 is a wet signal having a chorus effect by the chorus 15 and the multiplier 15
It is divided into dry signals multiplied by the coefficient by A. The multiplier 15B multiplies the wet signal output from the chorus 15 by a coefficient, and mutes the wet signal according to the type of parameter instructed to be changed. The adder 16 is a multiplier 15
The dry signal output from A and the wet signal output from the multiplier 15B are added to generate a chorus sound effect.

The output signal of the adder 16 is a wet signal including the signal delayed by the delay 17 and the multiplier 17A.
Is divided into dry signals multiplied by a coefficient. Multiplier 1
7B multiplies the wet signal output from the delay 17 by a coefficient, and mutes the wet signal according to the type of parameter instructed to be changed. The adder 18 is a multiplier 17A
And the wet signal output from the multiplier 17B are added to generate a delay sound effect.

The output signal of the adder 18 is divided into a wet signal having a reverberation effect by the reverb 19 and a dry signal multiplied by a coefficient by the multiplier 19A. Multiplier 19
B multiplies the wet signal output from the reverb 19 by a coefficient, and mutes the wet signal according to the type of parameter instructed to be changed. The adder 20 adds the dry signal output from the multiplier 19A and the wet signal output from the multiplier 19B to generate a reverb sound effect.
The output of the adder 20 becomes the output of the multi-effector.

Although the dry signal has been described above as a signal that bypasses each of the five effectors, the circuit may be configured as a signal that bypasses two or more effectors.

FIG. 7 is a flowchart showing the processing procedure of the multi-effector performed by the CPU. In step R1, various initial settings such as register initialization are performed.
In step R2, the panel 28 shown in FIG.
The interface 29 detects whether or not a parameter change event has occurred, and when the event has occurred, performs processing corresponding to the event. In step R3, the parameters changed are shown in FIG.
It is registered in the parameter table in the RAM shown in FIG. 5 to prepare for the determination as to whether or not the mute is a necessary parameter change. Also, after performing other necessary processing,
Returning to the event detection process of step R2, the process is repeated.

FIG. 8 is a flow chart showing details of the event detection processing shown in step R2 of FIG. In step S1, it is checked whether or not there is a program change. If a parameter change event of any effector is detected from the panel or MIDI interface, it is determined that there is a program change.

If there is no program change, it is sufficient to continue applying the effect with the parameters currently set, and the process ends without doing anything. If there is a program change, the process proceeds to step S2 and distortion processing is performed. After that, the filter process is performed in step S3, the chorus process is performed in step S4, the delay process is performed in step S5, and the step S5 is performed.
In step 6, the reverb process is performed and the process ends. The details of the processing of each effector will be described below.

FIG. 9 is a flow chart showing details of the distortion process performed in step S2 of FIG. In step T1, it is checked whether or not the distortion parameter is changed. If there is no change in the parameter, the current parameter may be maintained, and the process ends without doing anything.

On the other hand, if the parameters are changed,
In step T2, the multiplier wet signal is muted by the multiplier. After muting the wet signal, the parameter instructed to be changed in step T3 is set in the DSP, and the parameter is changed. After the parameter setting is completed, in step T4, the multiplication coefficient of the multiplier is returned to the original state, the mute of the wet signal is released, and the process is completed.

FIG. 10 is a flow chart showing details of the filter processing performed in step S3 of FIG. In step U1, it is checked whether or not the filter parameters are changed. If there is no change in the parameters, the process ends without doing anything.

On the other hand, if the parameters are changed,
In step U2, the wet signal of the filter is muted by the multiplier. After muting the wet signal, in step U3, the parameter instructed to be changed is set in the DSP, and the parameter is changed. After the parameter setting is completed, in step U4, the multiplication coefficient of the multiplier is returned to the original state, the mute of the wet signal is released, and the process is completed.

FIG. 11 is a flow chart showing details of the chorus process performed in step S4 of FIG. In step V1, it is checked whether the chorus parameters have been changed. If there is no change in the parameters, the process ends without doing anything.

On the other hand, if the parameters are changed,
In step V2, the wet signal of the chorus is muted by the multiplier. After muting the wet signal, in step V3, the parameter instructed to be changed is set in the DSP, and the parameter is changed. After the parameter setting is completed, in step V4, the multiplication coefficient of the multiplier is returned to the original state, the mute of the wet signal is released, and the process is completed.

FIG. 12 is a flow chart showing details of the delay process performed in step S5 of FIG. In step W1, it is checked whether or not the delay parameter is changed. If there is no change in the parameters, the process ends without doing anything. On the other hand, when the parameter is changed, the process proceeds to step W2, and it is checked whether or not the parameter to be changed is the delay time.

If the delay time is to be changed, the process proceeds to step W3 and the multiplier wet signal is muted by the multiplier. After muting the wet signal, in step W4, the parameter instructed to be changed is set in the DSP, and the parameter is changed. After the parameter setting is completed, in step W5, the multiplication coefficient of the multiplier is returned to the original state to cancel the mute of the wet signal, and the process is completed.

If the parameter change is not the delay time change, in step W6, the parameter is gradually changed using the interpolation function without muting. The process ends after the parameter change is completed.

FIG. 13 is a flow chart showing details of the reverb processing performed in step S6 of FIG. In step Y1, it is checked whether or not the reverb parameter has been changed. If there is no change in the parameter, the process ends without doing anything. On the other hand, if the parameter is changed, the process proceeds to step Y2, and it is checked whether or not the parameter to be changed is the delay time.

If the delay time is to be changed, the process proceeds to step Y3, where the multiplier mutes the reverb wet signal. After muting the wet signal, in step Y4, the parameter instructed to be changed is set in the DSP, and the parameter is changed. After the parameter setting is completed, in step Y5, the multiplication coefficient of the multiplier is restored to cancel the mute of the wet signal, and the process is completed.

If the parameter change is not the delay time change, in step Y6, the parameter is gradually changed using the interpolation function without muting. The process ends after the parameter change is completed.

As described above, in the case of changing a parameter that causes noise, such as changing the delay time,
When the wet signal is muted to change the parameters and the parameters are not changed so that noise is not generated, the parameter can be gradually changed without muting to reduce the feeling of sound interruption.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0067]

As described above, according to the present invention,
When instructing to change the parameter of the effect added to the musical tone signal, if the parameter change is related to the change of the delay time, the musical tone signal to which the effect is applied is muted and the change of the delay time is concerned. Otherwise, by outputting the musical tone signal to which the effect is applied without muting, it is possible to remove the noise sound caused by the parameter change and reduce the annoying sound cutoff feeling when the parameter is changed.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration example of a filter and a reverb configured by a DSP.

FIG. 2 is a circuit diagram showing a configuration example of a processing circuit using a delay line.

FIG. 3 is a graph showing changes in output level when only parameters of the filter of FIG. 1 are changed.

FIG. 4 is a flowchart showing a process when a filter parameter is changed.

FIG. 5 is a flowchart showing a process when a reverb parameter is changed.

FIG. 6 is a circuit diagram showing a configuration example of a multi-effector including five effectors.

FIG. 7 is a flowchart showing a processing procedure of a multi-effector performed by a CPU.

8 is a flowchart showing details of the event detection process shown in step R2 of FIG.

9 is a flowchart showing details of distortion processing performed in step S2 of FIG.

FIG. 10 is a flowchart showing details of filter processing performed in step S3 of FIG.

FIG. 11 is a flowchart showing details of chorus processing performed in step S4 of FIG.

FIG. 12 is a flowchart showing details of a delay process performed in step S5 of FIG.

13 is a flowchart showing details of the reverb processing performed in step S6 of FIG.

FIG. 14 is a block diagram showing a configuration of an effector device according to an embodiment of the present invention.

FIG. 15 is a schematic diagram showing the contents of a parameter table provided in the RAM 26 of FIG.

FIG. 16 is a circuit diagram showing a configuration example of a conventional effector.

FIG. 17 is a graph showing changes in output level when parameters are changed.

[Explanation of symbols]

1 filter, 3 reverb, 2,4 adder, A, B, C, D multiplier, 5 adder,
6 delay line, 7,8 multiplier, 11 distortion, 13 filter, 15 chorus, 17 delay, 19 reverb, 1
2, 14, 16, 18, 20 adder, 11A, 13
A, 15A, 17A, 19A multiplier, 11B, 1
3B, 15B, 17B, 19B Multiplier, 51 Filter, 54 Reverb, 53,56 Adder, 52,55 Multiplier, 57 Multiplier

Claims (2)

[Claims] 1. An effect imparting means for imparting an effect to a tone signal supplied from the outside, an instructing means for instructing to change a parameter of an effect imparted by the effect imparting means, and a change instruction by the instructing means for effecting the effect. Parameter checking means for determining whether or not to give a change instruction to the delay time in the adding means, and when the parameter checking means determines that the delay time is changed, the effect applying means outputs the musical tone signal to which the effect is added. An effector having: an output unit that mutes and outputs, and when it determines that the delay time is not changed, outputs the tone signal to which the effect is imparted by the effect without muting. 2. A plurality of effect imparting means connected in series for imparting different effects to a musical tone signal; a bypass means for bypassing at least one of the plurality of effect imparting means to transmit a musical tone signal; Instruction means for instructing to change each parameter of the effect imparting means, and a parameter for determining whether or not the change instruction by the instructing means is an instruction to change the delay time in each of the plurality of effect imparting means When the checking means and the parameter checking means determine that the delay time is changed, the corresponding effect imparting means mutes the tone signal to which the effect is applied, and when it is determined that the delay time is not changed, the corresponding effect is applied. And an output unit for outputting the musical tone signal to which the adding unit has given the effect without muting.