JP2000196388A - Voice signal processor and electronic equipment having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an output voice signal suitable for the hearing ability of a listener without predicting and specifying the level range of an input voice signal or the dynamic range of an audio output voice signal. SOLUTION: For the voice signal processor, an input voice signal is inputted from an input terminal 8, and the level of the input voice signal is detected by a level detecting means 1 so that the detected output can be obtained. Then, a gain control characteristic varying means 3 varies the gain control characteristic curve of an amplifier 2 by referring to an output from an output varying means 9 obtained by operating the external operating mechanism of the output varying means 9 by a listener and the detected output so that the voice output can be made suitable for the listening ability of the listener.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal processing apparatus and an electronic apparatus having the same, for example, a hearing aid, a telephone, a loudspeaker, an audio signal audio level conversion apparatus and a volume control apparatus used in the field of audio communication. More particularly, the present invention relates to an audio signal processing device capable of obtaining an output audio signal suitable for the hearing of a listener by varying a gain control characteristic of an amplifier, and an electronic apparatus including the same.

[0002]

2. Description of the Related Art When transmitting and reproducing sound, a transmission system,
When the dynamic range of the playback system is not sufficiently wide, or when the receivable dynamic range is narrow such as for people with hearing impairment, the amplification of the small-level input audio signal is increased, and the amplification of the large-level input audio signal is increased. There is known a level compression / amplification method for performing level conversion of an output audio signal with respect to an input audio signal by using a non-linear gain control characteristic of reducing the level.

[0003]

However, in the above-described conventional level compression amplification processing, there are the following problems with respect to setting and operational stability. In order to obtain the desired level conversion operation, the level range of the input audio signal from the reproduction system or the transmission system and the dynamic range of the audible output audio signal are predicted and specified so as to match the listener's hearing. The nonlinear gain control characteristic must be set in accordance with the specified dynamic range of the input audio signal and the output audio signal. Therefore, the width of the identifiable level of the input audio signal and the width of the audible audio output dynamic range are limited by the set gain control characteristics, and thus become narrower, and the level of the input audio signal and the audible audio output dynamic range are specified. If the level exceeds the level range, the expected level conversion operation cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and does not specify the level range of an input audio signal or the dynamic range of an audible output audio signal in advance without specifying the level range of an input audio signal and the listening range. It is an object of the present invention to provide an audio signal processing device capable of variably setting the above-described gain control characteristic in accordance with a possible dynamic range situation, and an electronic device including the same.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, an audio signal processing apparatus according to the present invention and an electronic apparatus having the same have a function of converting an input audio signal input to the amplifier based on a gain control characteristic of the amplifier. Perform either amplification or compression,
In an audio signal processing device that outputs a desired output audio signal, a level detection unit that detects a voiced sound level of the input audio signal and generates a detection output, and an external operating mechanism and Output variable means for generating a gain control characteristic variable output by any of the external information signals,
A gain control characteristic curve for controlling the gain of the amplifier based on the detection output and the gain control characteristic variable output can be defined by a predetermined function with a specific level of the input audio signal as a boundary, and is continuous at the boundary. And a gain control characteristic varying means capable of varying the gain control characteristic of the amplifier.

Further, a preferred embodiment of the audio signal processing apparatus of the present invention and an electronic apparatus equipped with the same are described in the following (1).
To (6). (1) The gain control characteristic changing means sets the gain control characteristic curve
The output audio signal is positively fed back to the input audio signal, and the output is within a range surrounded by a maximum gain control curve that does not destabilize the gain control of the amplifier and a minimum gain control curve where the gain of the amplifier is zero. It can be varied within a range surrounded by an unpleasant threshold point for limiting the maximum output of the audio signal and a background noise suppression point which is the minimum value of the output audio signal for suppressing the influence of the background noise.

(2) The gain control characteristic varying means includes a discomfort threshold point for limiting the maximum output of the output audio signal and a background noise suppression point which is the minimum value of the output audio signal for suppressing the influence of background noise. It can be varied to obtain a desired output audio signal.

(3) The gain control characteristic varying means, when there is a sound insulation device for attenuating the audio output generated from the output audio signal, adjusts the gain control characteristic curve in accordance with the attenuation characteristic of the sound insulation device. Can be varied below the minimum gain control curve where is zero.

(4) The gain control characteristic varying means can vary the gain control characteristic curve by varying either a specific level of the input audio signal or a gain corresponding to the specific level.

(5) The gain control characteristic variable means samples the detection output and the gain control characteristic variable output using two identical frequencies having different phases, and outputs a sample value of the detection output and a sample value of the detection output. The gain control characteristic curve can be changed with reference to the sampled value of the gain control characteristic variable output sampled at a later time.

(6) When the gain control characteristic variable output indicates an increase, the gain control characteristic variable means changes a specific level of the input audio signal in a direction approaching the sample value with the sample value of the detection output as a limit. Then, when the gain control characteristic variable output further increases, the maximum gain that does not cause the output audio signal to positively feedback the input audio signal to the gain corresponding to the specific level, thereby making the gain control of the amplifier unstable. When the gain control characteristic variable output shows a decrease in the direction approaching the control curve, the specific level of the input audio signal is changed in a direction approaching the sample value with the sample value of the detection output as a limit. Later, when the gain control characteristic variable output shows a decrease, the gain corresponding to the specific level is changed in a direction approaching the minimum gain control curve where the gain of the amplifier is zero, and from the output audio signal, If there is a sound insulation device that attenuates the generated audio output,
It is variable in a direction approaching a gain control curve set below the minimum gain control curve.

The operation of the above means will be described below. The level of the input audio signal is detected as a detection output by the level detection means, and the listener generates a gain control characteristic variable output by the output variable means via an information signal from an external operation mechanism or an external device. Since the gain control characteristic varying means controls the gain of the amplifier while varying the gain control characteristic with reference to these detection output and gain control characteristic variable output, the amplification degree of the input audio signal input to the amplifier is controlled, An output audio signal suitable for the level of the input audio signal and the hearing of the listener is obtained.

The gain control characteristics of the amplifier described above are, for example,
When a specific level of the input audio signal is set as a boundary and the input audio signal smaller than the specific level is input to the amplifier, the rate of change of the gain is 1 or less. , The gain change rate being equal to or more than 1, which is defined by a predetermined function with a specific level of the input audio signal as a boundary and defined by a gain control characteristic curve having a continuous boundary. The specific level of the input audio signal is, for example, an average level of the input audio signal suitable for an expected listening environment and a listener's hearing. Therefore, if the input audio signal exceeds a certain level,
The output audio signal is compressed and decompressed when it is below a specific level, and gain control is performed so that this specific level can be varied by an external operating mechanism or information signal to obtain an output audio signal suitable for the listener. Will be

The output varying means varies the above-mentioned specific level of the input audio signal in accordance with the listener and the listening environment, thereby indirectly varying the gain of the amplifier. By generating a gain control characteristic variable output by the operating mechanism or the information signal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an audio signal processing apparatus of the present invention and an electronic apparatus equipped with the same will be described below with reference to FIGS. In order to simplify the understanding of the present invention, an operation of a general level compression process will be described with reference to FIGS. 10 and 11 from the viewpoint of a gain control characteristic curve. The term curve used in the present invention includes a straight line in the meaning of Riemannian geometry. Further, the term voice used in the present invention does not mean only human voice, but also includes so-called general audio and sound.

FIG. 10 shows a gain control characteristic curve of an output audio signal versus the level of an input audio signal of an amplifier used in a general level compression amplification process. FIG.
As shown by the dotted line in FIG. 10A, the slope of the gain control characteristic curve is smaller than that of the solid line, that is, the smaller the rate of change of the gain, the greater the degree of level compression. As shown by the dotted line in FIG. If the slope of the gain control characteristic curve is the same, it means that the higher the gain, the higher the gain. That is, in the case of the gain control characteristic curve in which the degree of level compression is large as shown in FIG. 10A, the amplification degree is higher when the level of the input audio signal is lower than when the level of the input audio signal is higher.

Further, in order to perform level conversion by a non-linear gain control characteristic curve depending on the level range of the input audio signal, the gain control characteristic curve of the amplifier may have a bending point such as point A in FIG. Usually, this point A is called a "knee point". In the case of FIG. 11, an output audio signal whose dynamic range is compressed and converted is obtained at the level of the input audio signal larger than the point A, and an output audio signal whose dynamic range is expanded and converted at the level of the input audio signal smaller than the point A. Is obtained.

In addition to the above-mentioned point A, as shown in FIG. 11, point B for limiting the maximum output level of the output audio signal converted by the gain control characteristic curve of the amplifier is called "discomfort threshold point". The point C for determining the output audio signal converted by the gain control characteristic curve of the amplifier at the level of the small input audio signal is referred to as a “background noise suppression point”. The input sound signal 0 dB at the point C means 2 × 10 ^-5 Pascal, and the background noise means environmental noise such as noise of an air conditioning fan.

When a signal from a microphone is amplified and output from a speaker and forms a feedback loop to be input to the microphone again, as in a PA (Public Address System) device (so-called loudspeaker) or a hearing aid, In order to prevent oscillation due to a so-called howling loop, an amplification gain limit as shown by a dashed line in FIG. 11 is provided, which is called a maximum gain control curve, and the above-mentioned movement range of the knee point A may be limited.

The above-described level compression / amplification processing may be performed on the instantaneous input audio signal level. However, since the output waveform is greatly distorted, in many cases, the level is higher than the immediately preceding input audio signal level. When the input audio signal is input, the operation to reduce the amplification level is performed instantly,
Conversely, when an input audio signal having a level lower than the immediately preceding input audio signal level is input, the operation of increasing the amplification degree is often performed with a time delay. With respect to the invention relating to the level compression amplification processing that operates as described above, Japanese Patent Application No. 10-183829 filed by the present inventors has disclosed.
As described in the specification, the audio signal processing apparatus of the present invention and the electronic apparatus having the same also follow the operation of the above-described level compression amplification processing.

FIG. 1 is a block diagram showing a schematic configuration diagram of an audio signal processing apparatus according to the present invention. The input audio signal is input to the input terminal 8, and the level of the input audio signal is detected by the level detection means 1. The level detecting means 1 comprises a voiced sound component passing filter 5 for passing only voiced sound components, and a rectifier 6
And a low-pass filter 7, and outputs a detection output from the low-pass filter 7. The delay means 4 serves to delay the gain control of the amplifier 2 when the input audio signal changes from a large level to a small level, and after this delay, the amplification of the input audio signal starts. Further, the output variable means 9 is attached to the outside,
A gain control characteristic variable output is output as an electric signal by an operation mechanism that can be operated by the listener, for example, a volume control (hereinafter, the output variable means 9 is represented by a volume control).

The gain control characteristic varying means 3 varies the gain control characteristic curve of the amplifier 2 with reference to the outputs of the output varying means 9 and the level detecting means 1. At this time, as described in claim 6, a sample value of the detection output of the level detection means 1 and a gain from the output variable means 9 immediately after the sample value are obtained by using two same frequencies having different phases. The sample value of the control characteristic variable output is referred to by the gain control characteristic variable means 3. The operation of the gain control characteristic varying means 3 of the audio signal processing device of the present invention when the volume control (not shown) is operated in the direction of increasing the output audio signal will be described below with reference to FIGS. .

In FIG. 2, it is assumed that the level of the output audio signal is set to 30 dB when the input audio signal is 0 dB, as indicated by the one-dot chain line in the maximum gain control curve that does not cause the howling described above. In the initial state, the gain control characteristic varying means 3 sets the point B, that is, the “discomfort threshold point” to B0, and the point C, that is, the “background noise suppression point”, to C0. It is assumed that the specific level is A0 and is on a straight line connecting B0 and C0.

The knee point specifies the level of the corresponding input audio signal so that it falls within the level of the specific input audio signal, that is, the level range of the input audio signal in the expected listening environment. Is converted to an output audio signal level range suitable for the listener. For example, in FIG. 2, the knee point is at point A, and the level of the corresponding specified input audio signal is 55d.
It means that it is near B.

The operation of the gain control characteristic varying means 3 when raising the volume control in this state will be described. (1a) When the actual level of the input audio signal at the time of operating the volume control is larger than the input audio signal at point A, that is, the above-described specific level of the input audio signal, as shown in FIG. Assuming that the level conversion characteristic of the input / output audio signal based on the gain control characteristic curve of the amplifier 2 immediately before the operation is a connection between the C0 point, the A point, and the B0 point, the level at the time when the volume control is performed is obtained. When the level of the input audio signal is 70 dB, that is, 55 dB or more, which is the expected specific level of the input audio signal at point A, the knee point is set to A1 on the maximum gain control curve.
Raise in the direction of the dot until the listener stops operating the volume control. If the listener is performing an operation to raise the volume even after reaching the A1 point, the knee point is set to A
From the point 1 on the maximum gain control curve, the actual input audio signal level is moved with a limit of 70 dB. In other words, the final knee point position A 'becomes a new point A, and the new gain control characteristic curve connects the points C0, A', and B0.

(2a) When the actual input audio signal level at the time of volume control operation is lower than a specific level of the input audio signal corresponding to the point A, for example, 45 dB, as shown in FIG. It is assumed that the level conversion characteristic of the input / output audio signal based on the gain control characteristic curve of the amplifier 2 immediately before the operation of the above is a connection of the C0 point, the A point, and the B0 point, and the A3 point corresponding to 45 dB is limited. Point A is moved in the direction of point A3 until the operation of the volume control is stopped. Even if the listener reaches point A3, if the listener has performed an operation to increase the volume, the user increases the volume from point A3 to point A4 on the maximum gain control curve in the vertical direction from point A3 until the operation is stopped. The final knee point position A 'thus obtained becomes a new point A. That is, the new gain control characteristic curve is C0
Point, A 'point, and B0 point are connected.

(3a) As shown in FIG. 4, the point A is set on the maximum gain control curve from the beginning, and the level of the input / output audio signal based on the gain control characteristic of the amplifier 2 immediately before operating the volume control. Conversion characteristics are C0 point, A point, B0
Assuming that the points are connected, the knee point is indicated by a dashed line with a limit from a specific level of the input audio signal, point A to the actual input audio signal level, by the operation of increasing the volume control by the listener. On the maximum gain control curve. Actual input audio signal level is 45
If it is dB, the point A 'is the limit. If the actual input audio signal level is 70 dB, the point A "is the limit.

(4a) As shown in FIG. 5, when the range between the knee point A and the background noise suppression point C0 is an expansion amplification area, and its slope, that is, the rate of change in gain is large, The level fluctuation of the background noise may be emphasized and heard. At that time, C0 is raised in the direction of the point C1 and moved to the point C ', and the change rate of the gain is brought close to 1, so that the audibility of the low-level input audio signal becomes natural. This is because, when background noise is amplified by the characteristic of expansion amplification, the width of change in noise is greatly emphasized, and continuous noise called "za" becomes audible as "za" and "jar". The above is an embodiment of claim 3.

(5a) The discomfort threshold point B0 is an operation for increasing the volume as shown in FIG. 6 when the discomfort threshold of the listener and the state of hearing are known and the maximum output level may be increased. In this case, the output level of the output audio signal may be increased by moving from point B0 toward point B1 which is the discomfort threshold point corresponding to the maximum gain control curve to point B '. Claim 3
It embodies the following.

Next, the operation of the gain control characteristic varying means 3 of the audio signal processing apparatus of the present invention when the volume control, which is an external operation mechanism, is operated in the direction of decreasing the output audio signal will be described with reference to FIGS. It will be described with reference to FIG. (1b) When the input audio signal level at the time of operating the volume control is higher than the specific level of the input audio signal at point A, as shown in FIG. Assuming that the level conversion characteristic of the input / output audio signal is obtained by connecting points C0, A, and B0, the level of the actual input audio signal is larger than the level of the specific input audio signal at point A, that is, 55 dB. For example, if it is 65 dB, it is 6 which is the limit from the point A.
The listener is moved in the direction of point A5 corresponding to the actual input audio signal of 5 dB until the listener stops operating the volume control. If the listener has performed the operation of lowering the volume even after reaching the point A5, the user lowers the volume from the point A5 to the point A6 on the minimum gain control curve until the operation of the volume is stopped. The limit is point A6 where the gain is zero. In this way, the final knee point position A 'is changed to a new A
Points. That is, the new gain control characteristic curve is C0
Point, point A 'and point B0 are connected.

(2b) When the actual level of the input audio signal at the time of operating the volume control is lower than the specific level of the input audio signal corresponding to the point A, as shown in FIG. The level conversion characteristic of the input / output audio signal due to the gain characteristic of the amplifier 2 immediately before performing
If the actual input audio signal level is 55 dB or less, which is the specific level of the input audio signal at the point A, the knee point is set on the minimum gain control curve. The volume control is lowered in the direction of point A7 until the listener stops operating. If the listener is performing an operation of lowering the volume even after reaching point A7, the knee point is moved from point A7 on the minimum gain control curve with the actual input audio signal level as a limit. Thus, the final knee point position A 'becomes a new point A. That is, the new gain control characteristic curve is C0
Point, point A 'and point B0 are connected.

(3b) In the case where the listening receiver has a sound insulation device and has a function of attenuating an output audio signal,
Moving the knee point to a position below the minimum gain control curve, that is, a position where the gain is smaller than zero, or lowering the discomfort threshold point B or the background noise suppression point C in the sense that a loud sound is made smaller than it actually is. Thus, as shown in FIG. 9, it is also possible to suppress a loud and noisy sound to make it easier to listen. That is, the gain control characteristic curve connecting the points C ′, A ′, and B ′ converts the output audio signal into a sound smaller than the original input audio signal. This is used, for example, for adjusting the gain control characteristic of an output audio signal by adding a sound insulation effect to a receiving receiver for a sound-sensitive deaf person who has difficulty in hearing a loud sound or a small sound unless it is within a certain level range. . The above is an embodiment of claim 4.

If the audio signal processing apparatus of the present invention described above is used for a volume control apparatus used in an electronic device such as a hearing aid, a telephone, a loudspeaker, an audio communication device, and an audio video device, the level of the input audio signal is determined in advance. Obviously, it is possible to obtain the output sound adapted to the listening environment and the listener without predicting and specifying the range and the dynamic range of the output sound signal that can be heard.

[0034]

As described above, according to the audio signal processing apparatus of the present invention and the electronic equipment having the same, the audio is transmitted and reproduced, and a sufficient dynamic range and audio output when the hearing impaired hears the audio. If it cannot be ensured, the gain control characteristic curve is varied to amplify and compress the audio output, and it is not necessary to predict and set in advance the possible dynamic range of the listener, and the listener's subjective Since the gain control characteristic can be changed by the volume control operation based on the judgment, it is possible to obtain a sound output suitable for the hearing of the listener. When the audio signal processing device of the present invention is provided in an electronic device such as a hearing aid, a telephone, a loudspeaker, a voice communication device, and an audio / video device, there is an effect that an electronic device with excellent sound quality that is easy for a listener to set can be obtained. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an audio signal processing device according to the present invention.

FIG. 2 is a gain control characteristic diagram for explaining a gain control characteristic when an operation of increasing the volume is performed in the operation of the gain control characteristic variable means of the audio signal processing device of the present invention.

FIG. 3 is a gain control characteristic diagram for explaining another gain control characteristic when an operation of increasing the volume is performed in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 4 is a gain control characteristic diagram for explaining still another gain control characteristic when an operation of increasing the volume is performed in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 5 is a gain control characteristic diagram for explaining a gain control characteristic for suppressing background noise in the operation of the gain control characteristic variable means of the audio signal processing device of the present invention.

FIG. 6 is a gain control characteristic diagram for explaining a gain control characteristic when the discomfort threshold point is increased in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 7 is a gain control characteristic diagram for explaining a gain control characteristic when an operation of reducing the volume is performed in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 8 is a gain control characteristic diagram for explaining another gain control characteristic when an operation of reducing the volume is performed in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 9 is a gain control characteristic diagram for explaining a gain control characteristic for a person with hearing impairment in the operation of the gain control characteristic varying means of the audio signal processing device of the present invention.

FIG. 10 is a gain control characteristic diagram for explaining the properties of the gain control characteristic curve.

FIG. 11 is a gain control characteristic diagram for explaining another characteristic of the gain control characteristic curve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Level detection means, 2 ... Amplifier, 3 ... Gain control characteristic variable means, 4 ... Delay means, 5 ... Voiced sound component pass filter,
6 rectifier, 7 low-pass filter, 8 input terminal, 9
... Variable output means

Claims (8)

[Claims] 1. An audio signal processing device which amplifies or compresses an input audio signal input to the amplifier based on a gain control characteristic of the amplifier and outputs a desired output audio signal. Level detecting means for detecting the level of the voiced sound and generating a detection output, and a gain control characteristic variable output generated by one of an external operation mechanism and an external information signal in order to obtain the desired output audio signal. Output variable means, a gain control characteristic curve for performing gain control of the amplifier based on the detection output and the gain control characteristic variable output, a predetermined function with a specific level of the input audio signal as a boundary And a gain control characteristic varying means capable of varying the gain control characteristic of the amplifier by changing the gain control characteristic so as to be continuous at the boundary. Processing equipment. 2. The gain control characteristic varying means according to claim 1, wherein said gain control characteristic curve is a maximum gain control curve which does not cause the output audio signal to positively feed back to said input audio signal and make the gain control of said amplifier unstable. An uncomfortable threshold point for limiting the maximum output of the output audio signal and a minimum of the output audio signal for suppressing the influence of background noise within a range surrounded by a minimum gain control curve in which the gain of the amplifier is zero. 2. The audio signal processing device according to claim 1, wherein the audio signal processing device can vary within a range surrounded by a background noise suppression point that is a value. 3. The gain control characteristic varying means includes an unpleasant threshold point for limiting a maximum output of the output audio signal, and a background noise suppression point which is a minimum value of the output audio signal for suppressing the influence of background noise. 2. The audio signal processing device according to claim 1, wherein the audio signal processing device can be varied to obtain the desired output audio signal. 4. When there is a sound insulation device for attenuating an audio output generated from the output audio signal, the gain control characteristic varying means adjusts the gain control characteristic curve in accordance with the attenuation characteristic of the sound insulation device. 2. The audio signal processing device according to claim 1, wherein the gain of the amplifier can be changed below a minimum gain control curve where the gain is zero. 5. The gain control characteristic curve unit may vary the gain control characteristic curve by changing one of the specific level of the input audio signal and a gain corresponding to the specific level. The audio signal processing device according to claim 1, wherein: 6. The gain control characteristic varying means samples the detection output and the gain control characteristic variable output using two identical frequencies having different phases, and obtains a sample value of the detection output and the detection value. 2. The audio signal processing apparatus according to claim 1, wherein the gain control characteristic curve can be changed with reference to a sample value of the variable gain control characteristic sampled at a time after a sample value of the output. . 7. The gain control characteristic varying means, when the gain control characteristic variable output indicates an increase, sets the specific level of the input audio signal close to the sample value with a sample value of the detection output as a limit. When the gain control characteristic variable output further increases, the output audio signal positively feedbacks the gain corresponding to the specific level to the input audio signal, and controls the gain control of the amplifier. Is changed in a direction approaching the maximum gain control curve that does not cause an unstable state, and when the gain control characteristic variable output indicates a decrease, the specific level of the input audio signal is limited to a sample value of the detection output. When the gain control characteristic variable output shows a decrease after that, the gain corresponding to the specific level becomes zero, and the gain of the amplifier becomes zero. If there is a sound insulation device that changes in a direction approaching the minimum gain control curve and attenuates the audio output generated from the output audio signal, the minimum gain control curve is changed according to the attenuation characteristics of the sound insulation device. 2. The audio signal processing device according to claim 1, wherein the signal is varied in a direction approaching a gain control curve set downward. 8. An electronic apparatus comprising the audio signal processing device according to claim 1.