JPH02222207A - Hearing sense compensation device - Google Patents

Abstract

PURPOSE:To correct an equal loudness characteristic accurately even when an input signal level is small or large by using a sound volume level detection circuit to detect an output signal level of a hearing sense compensation device thereby obtaining a hearing sense compensation control signal. CONSTITUTION:A hearing sense compensation filter 1 corrects a frequency characteristic at a small sound quantity of a person with respect to an input voice signal and a sound volume control circuit 2 receives an output signal of the bearing sense compensation filter 1 and controls the sound volume with a sound volume control signal thereby obtaining the output of the hearing sense compensation device. Then a sound volume level detection circuit 3 detects an output signal level of the sound volume control circuit 2 and uses the sound volume level detection signal as the bearing sense compensation control signal to control the characteristic of the hearing sense compensation filter 1. Thus, even when the level of the input signal is small or large, the equal loudness characteristic is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hearing compensation device used in television receivers, stereo amplifiers, and the like.

2. Description of the Related Art The sound pressure that humans perceive as the same volume differs depending on the frequency, and furthermore, this frequency characteristic changes depending on the magnitude of the sound pressure. The above-mentioned sound pressure-frequency characteristics are called equal-loudness characteristics, and the standard equal-loudness level curve (Fig. 3) adopted in the international standard 130226 is generally used. It can be seen that the auditory sense becomes less sensitive in the low and high temperature ranges at low volumes.To compensate for this decrease in sensitivity, a hearing compensation device (loudness device) is used to emphasize the low and high frequencies at low volumes. An example of a conventional hearing compensation device will be described below with reference to the drawings.

FIG. 5 shows an example of the configuration of a conventional hearing compensation device.

In FIG. 5, l is a hearing compensation filter that corrects the frequency characteristics of human hearing at low volumes for the input audio signal, and 2
is a volume control circuit that controls the volume of the output of the auditory compensation filter 1 using a volume control signal.

The frequency characteristics of the hearing compensation filter 1 are controlled by a sound quality control signal. In other words, the sound pressure is approximated by the volume control <'HIJ,
When the sound pressure is low (the amount of attenuation in the volume control circuit is large), the bass and treble ranges are emphasized. Figure 4 shows the volume control amount (OdB, -30dB, -50dB, -70dB).
An example of the frequency characteristics of the auditory compensation filter 1 when the following is shown is shown.

Problems to be Solved by the Invention In the hearing compensation device shown in Fig. 5, the frequency characteristics of the hearing compensation filter are controlled only by the volume control signal. The approximation error between the pressure and the volume control amount becomes large, and the auditory compensation filter cannot accurately correct the standard equal loudness characteristic.

Furthermore, the audio signal processing device for boat fishing has a sound quality control circuit. In an audio signal processing device that includes both a sound quality control circuit and a hearing compensation device, the circuit scale is large (and the amount of signal processing is large), so signal quality is likely to deteriorate.

The first object of the present invention is to provide a high input signal when the level of the input signal is low. A second object of the present invention is to provide a hearing compensation device that has a small circuit scale and can minimize signal quality deterioration.

Means for Solving the Problems In order to solve the above problems, the hearing compensation device of the present invention includes a hearing compensation filter that corrects the frequency characteristics of human hearing at low volumes with respect to an input audio signal, and a hearing compensation filter that corrects the frequency characteristics of the human hearing at low volumes. The level detection circuit comprises: a volume control circuit that receives an output signal as an input, controls the volume using a volume control signal, and outputs the sound volume from the hearing compensation device; and a volume level detection circuit that detects an output signal level of the volume control circuit. The characteristics of the auditory compensation filter are controlled by the output signal of the hearing compensation filter.

It also includes a sound quality control circuit that emphasizes and suppresses the high frequency range and emphasizes and suppresses the low temperature range with respect to the input audio signal, and a hearing compensation device that takes the output signal of the sound quality control circuit as input and controls the volume with a volume control signal. The sound quality control circuit includes a volume control circuit as an output, and is configured to control the frequency characteristics of the sound quality control circuit using the sound quality control signal and the volume control signal.

Furthermore, a sound quality control circuit that emphasizes and suppresses the high frequency range and low temperature range with respect to the input audio signal, and a hearing compensation device that takes the output signal of the sound quality control circuit as input and controls the volume with a volume control signal. The sound quality control circuit includes a volume control circuit for outputting an output, and a volume level detection circuit for detecting an output signal level of the volume control circuit, and controls frequency characteristics of the sound quality control circuit using a sound quality control signal and an output signal of the level detection circuit. It is configured like this.

Effects The present invention operates as follows and solves the above problems with the above-described configuration.

(1) By detecting the output signal level of the hearing compensation device by the volume level detection circuit and using it as a hearing compensation control signal, the frequency characteristics of the hearing compensation device can be controlled using the amount of electrical energy that actually drives the speaker. That is, when the input signal level is low or high, it is possible to correct the equal loudness characteristic more accurately than the conventional hearing compensation device.

(2) By controlling filters with variable frequency characteristics in the treble and bass ranges using both the hearing compensation control signal and the sound quality control signal, the hearing compensation filter and the sound quality control filter can be shared, reducing the circuit size. . Furthermore, the number of filter stages through which the signal passes is reduced, and signal quality deterioration is minimized.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit diagram of a hearing compensation device according to a first embodiment of the present invention.

In FIG. 1, l is a hearing compensation filter that corrects the frequency characteristics of human beings at low volumes with respect to the input audio signal, and 2 is a hearing compensation filter that receives the output signal of the hearing compensation filter i and controls the volume using a volume control signal. A volume control circuit 3 outputs the output of the compensation device, and a volume level detection circuit 3 detects the output signal level of the volume control circuit 2.

4 is a high-noise filter that extracts only the high frequency range from the input signal; 5 is a low-pass filter that extracts only the low-frequency range from the input signal; and 6 is for adding the output signal of the bypass filter 4 and the output signal of the low-pass filter 5. a first addition circuit, 7 a first voltage control amplifier circuit which receives the output signal of the first addition circuit 6 as an input and uses the auditory compensation control signal as a gain control signal; 8 a first voltage control amplifier circuit which receives the output signal of the first addition circuit 6 and uses the hearing compensation control signal as a gain control signal; 9 is a second voltage-controlled amplifier circuit that receives the output signal of the hearing compensation filter I and uses the volume control signal as a gain control signal; 10 is a hearing compensation circuit that adds the output signal of the amplifier circuit 7; A rectifier circuit that rectifies the output signal of the device; 11 is a smoothing circuit that smoothes the output signal of the rectifier circuit 10; 12 is a logarithmic amplifier circuit that logarithmically converts the output of the smoothing circuit 11 and outputs it as a hearing compensation control signal. .

The bypass filter 4, the low-pass filter 5, and the first addition circuit 6 output high-frequency range components and low-temperature range components that are corrected by the auditory compensation filter when the sound volume is low. The correction component and the input signal are added in the second addition circuit 8, and by controlling the ratio by the first voltage control amplifier circuit 7, the auditory compensation filter characteristics shown in FIG. 4 can be obtained. The output signal of the hearing compensation device is converted into a DC signal by the rectifier circuit lO and the smoothing circuit 11. Since humans perceive sound volume logarithmically, the DC signal representing the output signal amplitude is logarithmically converted by the logarithmic amplifier circuit 12. As a result, a signal representing a volume level corresponding to human senses can be obtained. By using the volume level signal as a hearing compensation control signal to control the hearing compensation filter I, appropriate hearing compensation can be achieved in accordance with the volume level of the output signal even when the input signal level is low or high.

FIG. 2 shows a circuit diagram of a hearing compensation device according to a second embodiment of the present invention. In FIG. 2, 13 is a sound quality control circuit that emphasizes and suppresses the high frequency range and emphasizes and suppresses the low frequency range for the input audio signal, and 2 receives the output signal of the sound quality control circuit 13 and controls the volume with a volume control signal. This is a volume control circuit that outputs the signal as the output of the hearing compensation device.

14 is a band pass filter that extracts only the middle range from the input signal, 15 is a bypass filter that extracts only the high range from the input signal, 16 is a low pass filter that extracts only the low temperature range from the input signal, and 17 is the bypass filter 15.
a third voltage-controlled amplifier circuit, 18, which receives the output signal of and uses the first frequency characteristic control signal (treble) as a gain control signal;
inputs the output signal of the low-pass filter 16, and the second
The fourth frequency control signal (low temperature) is used as the gain control signal.
19 is a third addition circuit for adding the input signal, the output signal of the third voltage control amplification circuit 17, and the output signal of the fourth voltage control amplification circuit 18; 9 is the sound quality control circuit; A second voltage control amplifier circuit 20 which receives the output signal of the control circuit 13 as an input and uses the volume control signal as a gain control signal.
is a fourth signal that adds the volume control signal (treble) and the first sound quality control signal to obtain the first frequency characteristic control signal (treble);
An adder circuit 21 adds the volume control signal and the second sound quality control signal (low temperature) to produce the second frequency characteristic control signal (
This is the fifth adding circuit that sets the temperature (low temperature).

The input signal is once divided into a middle range, a high range, and a low range by a band pass filter 14, a bypass filter 15, and a low pass filter 16, and then mixed again in a third addition circuit 19. This mixing ratio is determined by the third voltage control amplifier circuit 1.
7 and the fourth voltage-controlled amplifier circuit 18, it is possible to emphasize and suppress the treble and bass ranges. Furthermore, the first sound quality control signal and the volume control signal are added in a fourth addition circuit 20 and a fifth addition circuit 21, and a frequency characteristic control signal for emphasizing and suppressing low and high tones is added. If you configure it so that the vocal range is emphasized,
The sound quality control filter and hearing compensation filter can be shared, reducing the circuit scale.

Effects of the Invention The present invention provides a hearing compensation filter that corrects the frequency characteristics of a human at a low volume with respect to an input audio signal, and a volume control signal that takes an output signal of the hearing compensation filter as an input, controls the volume with a volume control signal, and outputs the sound volume. a control circuit; and a volume level detection circuit that detects the level of the output signal of the volume control circuit; and the level of the input signal is controlled by controlling the characteristics of the auditory compensation filter using the output signal of the volume level detection circuit. When the noise level is small or large, the equal loudness characteristics can be corrected more accurately than conventional hearing compensation devices, and its practical effects are significant.

It also includes a sound quality control circuit that emphasizes and suppresses the high frequency range and emphasizes and suppresses the low frequency range with respect to the input audio signal, and a volume control circuit that receives the output signal of the sound quality control circuit and controls the volume using a volume control signal and outputs the output signal. By controlling the frequency characteristics of the sound quality control circuit using the sound quality control signal and the volume control signal, the circuit scale can be reduced and signal quality deterioration can be minimized. There is something big about it.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a first embodiment of the hearing compensation device of the present invention, FIG. 2 is a circuit diagram of a second embodiment of the hearing compensation device of the present invention, and FIG. 3 is a standard equal loudness level curve diagram. , FIG. 4 is a frequency characteristic diagram of an example of a hearing compensation filter, and FIG. 5 is a circuit diagram of a conventional hearing compensation device. 1...Hearing compensation filter, 2...Volume control circuit, 3...Volume level detection circuit, 4...
...Bypass filter, 5...Low pass filter, 6...First addition circuit, 7...
・First voltage control amplifier circuit, 8... Second addition circuit, 9... Second voltage control amplifier circuit, lO・
... Rectifier circuit, 11 ... Smoothing circuit, 12
... Logarithmic amplifier circuit, 13 ... Sound quality control circuit, 14 ... Band pass filter, 15.
... Bypass filter, 16 ... Kawaguchi-pass filter, 17 ... Third voltage control amplifier circuit, 1
8...Fourth voltage control amplifier circuit, 19...
...Third power calculation circuit, 20...Fourth addition circuit, 21...Fifth addition circuit. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 3 Figure 4 Figure 63 (25Z!;D 5lab IK
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Claims (3)

[Claims] (1) A hearing compensation filter that corrects the frequency characteristics of human beings at low volume with respect to the input audio signal, and the output signal of the hearing compensation filter is input, the volume is controlled by a volume control signal, and the output is output from the hearing compensation device. Hearing compensation comprising a volume control circuit and a volume level detection circuit for detecting an output signal level of the volume control circuit, and controlling characteristics of the hearing compensation filter by the output signal of the volume level detection circuit. Device. (2) A sound quality control circuit that emphasizes and suppresses the high frequency range and emphasizes and suppresses the low frequency range with respect to the input audio signal, and a hearing compensation device that takes the output signal of the sound quality control circuit as input and controls the volume with a volume control signal. What is claimed is: 1. A hearing compensation device comprising: a volume control circuit that outputs a sound quality control signal; and a frequency characteristic of the sound quality control circuit is controlled by a sound quality control signal and the volume control signal. (3) A sound quality control circuit that emphasizes and suppresses the high frequency range and emphasizes and suppresses the low frequency range with respect to the input audio signal, and a hearing compensation device that takes the output signal of the sound quality control circuit as input and controls the volume with a volume control signal. and a volume level detection circuit that detects the output signal level of the volume control circuit, and the frequency characteristic of the sound quality control circuit is determined by the sound quality control signal and the output signal of the volume level detection circuit. A hearing compensation device characterized by controlling.