JP3018964U - Voice information converter - Google Patents

Abstract

(57) [Abstract] [Purpose] Set an arbitrary frequency band characteristic without distorting the original sound, give a sense of expansiveness of the sound image, and artificially add high frequency components to convert the timbre and sound quality. It creates a sound field close to the sound source. [Structure] The audio band of a stereo signal is divided into a plurality of bands to a predetermined level, and the audio division / combination unit 3 that combines the signals of the divided bands and the phase of the signal of the opposite channel are inverted. , A specific frequency component is generated from the output signal of the sound field conversion unit 4 and the sound field conversion unit to which this signal is added after being attenuated to a predetermined level, and this signal is used as the output signal of the sound field conversion unit. It is characterized in that it is configured with the high frequency signal generation unit 5 added.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an audio information conversion device capable of arbitrarily setting the sound quality characteristics of left and right stereo audio signals.

[0002]

[Prior art]

 In particular, in a compact disc digital recording / reproducing system, the upper limit of the recording frequency band is set to about 20 kHz, and therefore, high frequency components of 20 kHz or higher are not recorded on the recording medium. The upper high frequency components are not reproduced. However, it is said that high-frequency components above 20 kHz, which are difficult for humans to hear, have the effect of stimulating the brain waves of the listener to generate α waves when listening to music, making them comfortable and relaxed. . Therefore, when listening to music, it is preferable that the reproduced sound contains high-frequency components like analog records, but in particular, the compact disc digital recording / playback system contains high-frequency components as described above. There was a drawback that not.

[0003]

[Problems to be solved by the device]

 The present invention has been made in view of the above points, and its purpose is to eliminate the drawbacks of the conventional example, to give a sense of expanse of the sound image without distorting the original sound, and to improve the high frequency range related to the original sound. By adding components in a pseudo manner and creating a sound field that is close to a natural sound source, we are providing a voice information conversion device with a three-dimensional effect and a sense of presence.

[0004]

[Means for Solving the Problems]

 The audio information conversion device of the present invention divides the audio band of a stereo signal into a plurality of bands to obtain a predetermined level, and also an audio division / synthesis unit configured to combine the signals of the respective divided bands, and a signal of the opposite channel. After inverting the phase of the sound signal and attenuating it to a predetermined level, a specific frequency component is generated from the sound field conversion unit that adds this signal to the output signal of the voice division synthesis unit and the output signal of the sound field conversion unit. And a high-frequency signal generation unit that adds this signal to the output signal of the sound field conversion unit. In addition, the high frequency signal generator extracts a predetermined frequency component from the output signal of the sound field converter through a filter, converts this frequency component into a doubled frequency by the harmonic overtone generation circuit, and converts the converted frequency. The feature is that a component is added to the output signal of the sound field converter. In addition, the high frequency signal generator extracts a predetermined frequency component from the output signal of the sound field converter through the filter, and the frequency component of this frequency component is multiplied by n (n = 3 to 5) times. It is characterized in that the converted frequency component is added to the output signal of the sound field converter.

[0005]

[Action]

 According to the present invention, a left and right stereo audio signal is supplied to the audio division / synthesis unit, and the audio division / synthesis unit has a low-pass filter with a cut-off frequency of about 100 Hz, a band-pass filter, and a cut-off frequency of about 10 kHz. The high-pass filter divides the original sound into three parts, and raises the levels of the frequency components in the inner low frequency range and the high frequency range in each frequency band divided into these three parts with respect to the middle frequency range. Then, the respective frequency components are combined by the adder and supplied to the sound field conversion unit.

The sound field converter is connected from the right channel audio signal circuit to the adder of the left channel audio signal circuit via the first phase inversion circuit and the first level adjuster, and vice versa. The signal circuit is connected to the adder of the right channel audio signal circuit through the second phase inversion circuit and the second level adjuster, and the first and second level adjusters are controlled by the control signal of the variable operation terminal. The sound image localization can be adjusted to change the sound image localization (sound image localization changing means) to give the sound image a sense of expanse. Further, a specific frequency component of about 10 kHz to 20 kHz of the original sound is extracted by a bandpass filter, and the extracted specific frequency component is supplied to a harmonic overtone generation circuit to generate a high frequency component of about 20 kHz to 40 kHz. By adding this high frequency component to the audio output via the adder, it is possible to hear a frequency band component of approximately 20 kHz or more during reproduction.

As described above, the audio information conversion device emphasizes the low frequency range and the high frequency range, and adds a pseudo high frequency range component, so that the compact disc includes a frequency range of 20 Hz or lower or 20 kHz or higher. Even if it is not, the bass range is appropriately emphasized, and the frequency component of 20 kHz or more is reproduced, so that the sound can be broadened, the stereoscopic effect and the realism can be obtained.

[0008]

【Example】

 An embodiment of the voice information conversion device according to the present invention will be described based on the block diagram of FIG. In the figure, 1 is an input terminal of a left channel (hereinafter referred to as Lch) of a stereo audio signal, 2 is an input / output changeover switch, 2a is an input side changeover switch, 2b is an output side changeover switch, and 3 is a voice division. The voice division / synthesis unit 3 includes a low-pass filter 3a having a cutoff frequency of 100 Hz (hereinafter referred to as LPF3a), a bandpass filter 3b (hereinafter referred to as BPF3b), and a highpass having a cutoff frequency of 10 kHz. The output side of the LPF 3a, the level adjuster 3d, the level adjuster 3e on the output side of the BPF 3b, and the level adjuster on the output side of the HPF 3c. 3f is connected, and the level adjusters 3d, 3e, 3f are connected by a control signal from the variable operation terminal 3g. It has become variable possible. Reference numeral 3h is an adder that combines the respective signals divided into three.

Reference numeral 4 is a sound field converter, and this sound field converter 4 is supplied from the first phase inversion circuit 4a connected to Rch to the adder 4c via the first level adjuster 4b. Performing sound field conversion of the Lch stereo signal by adjusting the level adjuster 4b with the control signal supplied to the variable operation terminal 4d by adding the Rch phase inversion signal and the original Lch audio signal. You can Reference numeral 5 denotes a high-frequency signal generation unit, and this high-frequency signal generation unit 5 performs overtone processing on a bandpass filter 5a for extracting a signal component of a specific frequency band of approximately 10 kHz to 20 kHz and an output signal of this bandpass filter 5a. Overtone generation circuit 5b, level adjuster 5c provided on the output side of this overtone generation circuit 5b, operation terminal 5d for controlling this level adjuster 5c, band pass filter 5a, overtone generation circuit 5b and level adjustment It is composed of a line 5e that bypasses the leveling device 5c, and an adder 5f that adds the output signal of the level adjuster 5c and the signal of the bypass line 5e.

Reference numeral 6 is a bypass line for bypassing the voice information conversion function connected to the input / output changeover switches 2a and 2b, and 7 is an output terminal. Reference numerals 11 to 17 are reference numerals of respective parts of the Rch circuit of the stereo voice circuit. The configuration of this Rch circuit is the same as that of the Lch circuit described above, and the last digit of 11 to 17 is the Lch circuit. The same reference numerals as those of the respective parts of FIG.

In the audio information conversion device thus configured, the L / Rch signals of the stereo audio signal are supplied to the input terminals 1 and 11, respectively. Hereinafter, since the L / Rch signal processing is the same, only the Lch signal processing will be described. When the Lch signal is supplied to the input terminal 1, whether the Lch signal performs the voice information conversion function by the interlocked input / output switching switches 2a and 2b or outputs the voice information conversion function by bypassing. Selected by. Generally, when listening to stereo sound such as music, you can enjoy more powerful and realistic music by activating the voice information conversion function, but avoid adding the voice information conversion function to the original sound. This voice information converter can be bypassed if it needs to be transmitted over time.

As shown in the figure, when the input / output changeover switches 2 a and 2 b are set to operate the audio information conversion function, the input Lch signal is supplied to the audio division / synthesis unit 3. The Lch signal supplied to the audio division / synthesis unit 3 is divided into three by the LP F3a, BPF3b, and HPF3c having predetermined cutoff frequencies, and the level adjusters 3d, 3e, and 3f for the respective divided frequency bands. The level of each frequency band can be set arbitrarily. Specifically, the low-frequency range component of 100 Hz or lower that has passed through the LPF 3a and the high-frequency range component of 10 kHz or higher that has passed through the HPF 3c are set to be increased with respect to the middle range of the BPF 3b. Then, the original sound becomes a stereo audio signal having the frequency characteristic desired by the listener by synthesizing the signal components of the respective bands, which are divided into three parts and whose respective levels are adjusted, by the adder 3h.

Next, the above-mentioned Lch signal is supplied to the adder 4 c of the sound field converter 4. On the other hand, the Rch signal whose phase has been inverted by the first phase inversion circuit 4a from the Rch stereo audio signal circuit is supplied to the adder 4c via the first level adjuster 4b. As a result, it is possible to obtain a feeling of expansion of the stereo audio signal.

Further, the Lch signal is supplied to the high frequency signal generator 5, a specific frequency component of about 10 kHz to 20 kHz is extracted by the bandpass filter 5a, and the extracted specific frequency component of about 10 kHz to 20 kHz is overtone-generated. By supplying to the circuit 5b, it is possible to generate a high frequency component of approximately 20 kHz to 40 kHz. The overtone generating circuit 5b is composed of a well-known absolute value circuit (not shown) which is generally used, and this absolute value circuit uses an ideal diode circuit to generate a full-wave rectifying and adding circuit. It obtains a double frequency signal, and can accurately generate the overtone of the input voice signal. That is, the output signal of the harmonic overtone generation circuit 5b is adjusted by the level adjuster 5c and supplied to the adder 5f, while the Lch signals of the entire band from the bypass line 5e are added by the adder 5f, so that the Lch stereo output is produced. In the frequency band of the signal, it is possible to obtain a high frequency component extended to about 40 kHz.

As described above, by artificially adding the high frequency component of 20 kHz or more to the Lch output signal, during reproduction of the digital recording / reproducing system, a high frequency band that cannot be reproduced and is not recorded in the digital recording medium. Frequency components can be added to the reproduced audio signal for listening.

In the above embodiment, the high frequency signal generation unit extracts a predetermined frequency component from the output signal of the sound field conversion unit through the filter, and the frequency component is doubled by the harmonic overtone generation circuit. However, the high-frequency signal generator extracts a predetermined frequency component from the output signal of the sound field converter through a filter. At the same time, the frequency component may be converted into a frequency of n (n = 3 to 5) times by the n-th overtone generation circuit, and the converted frequency component may be added to the output signal of the sound field converter. Good. In the present embodiment, the low-pitched sound level is raised during low-pitched sound reproduction. However, a frequency divider circuit is used to obtain a half frequency and generate a frequency component of 20 Hz or less from the original sound. However, if this generated frequency component is added to the original sound, it becomes possible to perform more realistic low-pitched sound reproduction.

Although the Lch signal processing has been described above, it goes without saying that the Rch signal processing is similarly processed. Further, although the frequency characteristic of three divisions has been described in the voice division and synthesis unit 3, it is not limited to three divisions, and more divisions may be performed. Further, although the overtone generating circuit 5b has been described by using the absolute value circuit, it is not limited to the absolute value circuit and any circuit having an accurate overtone generating function may be used.

[0018]

[Effect of device]

 The audio information conversion device according to the present invention has a frequency characteristic in which a low frequency component of 100 Hz or less and a high frequency component of 10 kHz are emphasized in the middle frequency range, and a frequency component of approximately 20 to 40 kHz is added to the high frequency range. Since it is added, stereo reproduction with a three-dimensional and realistic sensation is possible. In addition, since the spread of the sound source can be set as desired, the spread of the stereo playback sound can be obtained, and in particular, the installation positions of the left and right speakers of radio cassette recorders, car audio equipment, etc. can be set at a sufficient distance. In a system that is difficult to secure, there is an effect that it is possible to obtain a feeling of sound image spread that is greater than the interval between the speakers.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a voice information conversion device according to the present invention.

[Explanation of symbols]

 1, 11 L / Rch input terminal 2, 12 Input / output changeover switch 3, 13 Voice division synthesis section 3a Low-pass filter (LPF) 3b Band-pass filter (BPF) 3c High-pass filter (HPF) 3d-3f Level adjuster 3g Variable operation Terminal 3h Adder 4,14 Sound field converter 4a First phase inversion circuit 4b First level adjuster 4c Adder 4d Variable operation terminal 5,15 High frequency signal generator 5a Bandpass filter 5b Overtone generator 5c Level Regulator 5d Operation terminal 5e Bypass line 5f Adder 6,16 Bypass line 7,17 Output terminal

Claims (3)

[Scope of utility model registration request] 1. A voice division / combination unit configured to divide a voice band of a stereo signal into a plurality of bands to have a predetermined level, and to combine the signals of the respective divided bands, and to invert the phase of a signal of an opposite channel. Then, after attenuating to a predetermined level, this signal is generated by generating a specific frequency component from the sound field conversion unit that adds this signal to the output signal of the voice division synthesis unit and the output signal of the sound field conversion unit. An audio information conversion device comprising a high-frequency signal generation unit that is added to an output signal of the sound field conversion unit. 2. The high frequency signal generation unit extracts a predetermined frequency component from the output signal of the sound field conversion unit through a filter, converts this frequency component into a doubled frequency by a harmonic overtone generation circuit, and performs this conversion. The audio information conversion device according to claim 1, wherein the frequency component is added to the output signal of the sound field conversion unit. 3. The high frequency signal generator extracts a predetermined frequency component from the output signal of the sound field converter through a filter, and the frequency component is n (n = 3) by an n harmonic overtone generation circuit.
To 5) times the frequency, and the converted frequency component is added to the output signal of the sound field conversion unit.