JPH11103226A - Sound reproduction device - Google Patents

Abstract

(57) [Problem] To provide a sound capable of receiving an audio signal with high clarity when a person whose hearing characteristics have deteriorated is away from a reproduction speaker without increasing the overall volume. It is an object to provide a playback device. SOLUTION: A listener listens to a reference signal reproduced by a signal generation means 6 and sets a minimum audible level in a level setting means 7. On the other hand, the input signal is divided into a plurality of bands by the band-pass filter 2 and the signal level is
Is detected by Then, after the amplitude is controlled by the amplitude control means 4 according to the minimum audible level and the level of the input signal, the signals of the respective bands are added by the adder 5 and reproduced from the speaker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound reproducing apparatus capable of hearing a voice signal with good clarity when a person having a degraded hearing characteristic listens at a place away from a speaker.

[0002]

2. Description of the Related Art Regarding the configuration of a conventional sound reproducing apparatus,
It is disclosed in Japanese Patent Application Laid-Open No. 5-199592. FIG. 8 shows the configuration diagram. 8, reference numeral 101 denotes a signal input unit, 102 denotes a bandpass filter, 103 denotes a gain control unit, 104 denotes an amplifier, 105 denotes an adder, and 106 denotes a speaker.

An acoustic signal input by a signal input means 101 is divided into a plurality of bands by a band pass filter 102. Then, the signal level in the band is detected by the gain control unit 103, and the amplifier 10 is controlled according to the detected level.
4 is controlled. The signals in the respective bands controlled by the amplifiers are added by the adder 105,
06 is reproduced.

Incidentally, the value of the amplification amount with respect to the detection level is set based on the hearing characteristics measured in advance. Particularly in the case of elderly people, a unique hearing characteristic called a recruitment characteristic is observed. An elderly person cannot hear a small sound due to an increase in the minimum audible level, but can hear the same sound as a normal hearing person if it is a certain size. That is, the dynamic range of the audible range is narrower than that of a normal hearing person. Such a phenomenon is called a recruitment characteristic, and the tendency is higher in a higher frequency region.

Therefore, in order to correct this recruitment characteristic, it is necessary to increase the amount of amplification for a small sound and to reduce the amount of amplification for a sound that is relatively large. However,
Since this recruitment characteristic varies from person to person, it is necessary to set the amount of amplification by measuring by listening to headphones for each individual. In addition, since it differs depending on the frequency, it is necessary to set a plurality of frequencies.

As described above, by measuring the recruitment characteristics and presetting an amplification amount to correct the recruitment characteristics, it becomes possible for an elderly person whose hearing characteristics have deteriorated to receive a good voice.

[0007]

However, in the above-described configuration, if the speaker portion is used as a hearing aid which is completely worn on the ear, good sound can be heard and listened to. In the case where the speaker and the listener are away from each other as described above, there has been a problem that even if the data of the recruitment characteristics measured by headphone listening is used, good correction cannot be performed due to different listening conditions.

The present invention has been made in view of the above problems, and provides a sound reproducing apparatus capable of receiving a sound signal with good clarity without increasing the overall volume when a person whose hearing characteristics have deteriorated is away from a speaker. The purpose is to do.

[0009]

In order to solve the above-mentioned problems, a sound reproducing apparatus according to the present invention comprises a signal generating means for generating a reference signal and a reproduction level of the reference signal being varied to set a minimum audible level. Level setting means, a signal input means for inputting an audio signal, a band-pass filter for dividing the audio signal into a plurality of bands, a level detecting means for detecting the level of the divided signal, and setting by the level setting means Amplitude control means for varying the amplitude level of the signal band-divided by the band-pass filter based on the detected minimum audible level and the level detected by the level detection means; and a plurality of amplitude-controlled signals controlled by the amplitude control means. The configuration includes an adder for synthesizing signals, and a selecting means for selecting any one of the signal of the adder and the signal of the signal generating means. To have.

Further, the sound reproducing apparatus of the present invention has a signal generating means for generating a reference signal, a reference signal level control means for automatically controlling a reproduction level of the reference signal, and whether or not the reproduced reference signal has been heard. Level setting means for setting the minimum audible level by inputting information as to whether or not there is a signal, a signal input means for inputting an audio signal, a band-pass filter for dividing the audio signal into a plurality of bands, and a level for the divided signal. Level detection means for detecting, and amplitude control means for varying the amplitude level of the signal band-divided by the band-pass filter based on the minimum audible level set by the level setting means and the level detected by the level detection means An adder that combines a plurality of signals whose amplitudes are controlled by the amplitude control means; It has a configuration which is characterized by comprising a selection means for selecting Laka one signal.

Further, the sound reproducing apparatus of the present invention has a signal generating means for generating a reference signal, a reference signal level control means for automatically controlling a reproduction level of the reference signal, and a sound volume of the reproduced reference signal. Correspondence analysis means for inputting the impression of the sound in multiple stages to derive the correspondence between the reproduction level and the psychological impression, signal input means for inputting the audio signal, and a band-pass filter for dividing the audio signal into a plurality of bands. ,
Level detection means for detecting the level of the divided signal;
Amplitude control means for varying the amplitude level of the signal band-divided by the band-pass filter based on the correspondence set by the correspondence analysis means and the level detected by the level detection means; and An adder for synthesizing a plurality of controlled signals; selecting means for selecting one of the adder signal and the signal from the signal generating means; and inputting an impression of a sound volume to be actually reproduced. This is characterized in that it is provided with an impression input unit that performs the following.

Further, the signal generating means generates band noise in the same band as the band divided by the band-pass filter or a sine wave having the same frequency as a frequency in the band.

Further, the reference signal level control means changes the reproduction level of the reference signal from a low level to a high level.
Alternatively, control is performed from a large level to a small level or randomly.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a configuration diagram of a first embodiment. In FIG. 1, 1 is an audio signal input means, 2 is a band pass filter (BPF), 3 is a level detection means, 4 is an amplitude control means, 5 is an adder, 6 is a signal generation means, 7 is a level setting means, and 8 is a level setting means. A selector, 9 is an amplifier, 10 is a speaker, 11 is a listener, and 12 is a remote controller.

First, the listener 11 selects b with the selector 8 so that the reference signal of the signal generating means 6 is reproduced from the speaker 10. Then, a control signal is sent from the listening position to the level setting means 7 using the remote controller 12, and the reproduction level of the reference signal is varied to set a minimum level (minimum audible level) at which the reference signal can be heard. This minimum audible level needs to be set for all frequencies divided by the band-pass filter 2. For example, 2
0Hz to 500Hz, 500Hz to 2KHz, 2KHz
If it is divided into three bands of ~ 20KHz,
Band noises in the same frequency band are reproduced by the signal generating means 6, and a minimum audible level is set for each band noise. A sine wave may be used instead of band noise,
In this case, a sine wave having a frequency within each frequency band is preferably reproduced.

Next, a is selected by the selector 8 so that the input signal is reproduced. The signal input by the audio signal input means 1 is divided into a plurality of bands by the band-pass filter 2, and the signal level of each band is
Is detected by The amplitude is controlled by the amplitude control means 4 in accordance with the preset minimum audible level and the level of the input signal, and the signals in the respective bands are added by the adder 5. Finally, the data is reproduced from the speaker 10 through the amplifier 9.

Next, the relationship between the set value of the minimum audible level, the input level and the amplitude control amount will be described. FIG.
FIG. 3 is a diagram showing a relationship between an input level and an output level after an input signal is amplitude-controlled. The horizontal axis is the input level, and the vertical axis is the output level. In FIG. 2, c is the characteristic when the ratio between the input level and the output level is 1: 1 without performing the amplitude control, and d is the characteristic when the amplitude control is performed. The maximum level of the input signal is 0 dB, and the minimum level is -8.
It is illustrated as 0 dB.

For example, the minimum audible level of the listener is -50.
It is assumed that dB is set. In this case, the listener is -5
Since a signal having a level of 0 dB or less cannot be heard, -50
It is necessary to amplify a signal of less than dB to at least -50 dB. d is the minimum level sound of -80 dB to -50
This is a characteristic amplified to dB. The amplitude of the input signal is controlled by the amplitude control means 4 having such input / output characteristics.

On the other hand, even if a characteristic obtained by amplifying the whole by 30 dB like the characteristic of e is used, a sound of a small level of -50 dB or less can be similarly heard, but an input signal of a large level becomes too large. Feel psychologically noisy. Therefore, it is preferable to use the characteristic of d in which a sound of a small level is greatly amplified and a sound of a large level is not greatly amplified. Such input / output characteristics are set by the amplitude control means 4 of each band.

Although the band is divided into three bands, 1 oc
The division may be performed using the t bandwidth or the critical bandwidth. In particular, more accurate correction is possible by using a critical band closest to the human auditory processing mechanism.

As described above, the minimum audible level is measured at the position where the user actually watches the television or the like, and the dynamic range of the input signal is compressed based on the result. Degree.

(Embodiment 2) FIG. 3 is a configuration diagram of a second embodiment. This is to more accurately obtain the minimum audible level in the first embodiment.

In FIG. 3, 1 is an audio signal input means, 2 is a band pass filter (BPF), 3 is a level detection means, 4 is an amplitude control means, 5 is an adder, 6 is a signal generation means, and 7 is a level setting. Means, 8 is a selector, 9 is an amplifier, 10 is a speaker, 11 is a listener, 12 is a remote controller, and 13 is reference signal level control means.

As in the first embodiment, the listener first selects b with the selector 8 so that the reference signal is reproduced. The level of the reference signal is randomly varied by the reference signal level control means 13 and reproduced from the speaker 10. For example, a signal of 5 dB steps from -80 dB to 0 dB is reproduced at random a plurality of times. Then, the listener 11 listens to the reference signal and sends a check signal to the level setting means 7 by pressing a button on the remote controller only when a sound is heard. Then, the level at which the ratio of hearing and the ratio of non-hearing become 50% is set as the minimum audible level. The subsequent operation is the same as in the first embodiment.

Although the control of the level of the reference signal is performed at random, the reproduction may be performed in order from a low level to a high level or from a high level to a low level.

The minimum audible level is a level at which the ratio of hearing and the ratio of non-audibility are 50%. However, the minimum audible level may be a level at which the ratio of hearing is 50% or more.

As described above, the level of the reference signal is not controlled by the listener himself, but by automatically controlling the level to hear the sound and objectively determine whether the listener can hear. Thus, the minimum audible level can be set accurately.

The measuring method used here corresponds to a method called a constant method or a limit method among psychophysical measuring methods, and is an optimum method for obtaining a threshold value. The case of the first embodiment corresponds to a method called an adjustment method. In this method, since the listener adjusts itself, the threshold value can be obtained in a short time, but an error becomes large as compared with the constant method or the limit method.

(Embodiment 3) FIG. 4 is a configuration diagram of a third embodiment. This is to set the amount of amplification of the output signal level with respect to the input signal level in the first embodiment using a human impression expression.

In FIG. 4, 1 is an audio signal input means, 2 is a band pass filter (BPF), 3 is a level detection means, 4 is an amplitude control means, 5 is an adder, 6 is a signal generation means, 8 is a selector, 9 is an amplifier, 10 is a speaker,
11 is a listener, 12 is a remote controller, 13 is reference signal level control means, 14 is correspondence analysis means, and 15 is impression input means.

As in the second embodiment, reference signals having different signal levels are automatically reproduced. The listener 11 makes the impression of the loudness of the sound on the remote controller 1 on a multi-step scale.
2 to the correspondence analysis means 14.

FIG. 5 shows a seven-step psychological scale relating to the loudness of the sound, and the listener inputs an impression of the loudness of the reference signal using the psychological scale. Then, the correspondence analysis unit 14 derives the correspondence between the impression of the loudness of the sound and the reproduction level. For example, "small sound" is -6
5dB to -50dB, "quite small" is -5
0 dB to -35 dB, "slightly smaller" is -35
dB to -25dB, "just right" is -25
dB to -15 dB, "slightly larger" is -15 dB
B to -10 dB, "very large" is -10 dB
It is assumed that the range from B to -5 dB and the "too large" range is from -5 dB to 0 dB.

The listener inputs the reproduction level which he or she actually wants to hear, using the impression input means 15. FIG. 6 shows an example of the impression input means. Reference numeral 21 denotes a portion for setting the minimum value of the reproduction level, and reference numeral 22 denotes a portion for setting the maximum value of the reproduction level. For example, if one wants to listen in a range from "very small" to "somewhat large", the level range is from -50 dB to -10 dB. In this case, the amplitude control means 4 controls the amplitude so that the input signal falls within the range of this level. FIG. 7 shows input / output level characteristics. In FIG. 7, c is a characteristic in the case where the ratio between the input level and the output level is 1: 1 without performing the amplitude control, and f is a characteristic in which the amplitude is controlled to a range of a desired size. The dynamic range from -80 dB to 0 dB has been compressed from -50 dB to -10 dB. The subsequent operation is the same as in the first and second embodiments.

Although the scale of the psychological impression is set at seven levels, it is not limited to this. As described above, by using the correspondence between the level and the psychological impression, the volume of the sound that the listener wants to hear can be set in a psychological expression, and the level adjustment that is easy for the listener to understand can be performed.

[0036]

According to the present invention, the minimum audible level is measured at a position where the user actually watches a television or the like, and the dynamic range of the input signal is compressed based on the result. Good speech intelligibility can be obtained at the position.

Further, instead of controlling the level of the reference signal by the listener himself, the level is automatically controlled so that the listener hears the sound and objectively determines whether or not the listener can hear the sound. An accurate minimum audible level can be set.

Further, by using the correspondence between the reproduction level and the psychological impression, the volume of the sound that the listener wants to hear can be set in a psychological expression, and the level adjustment that is easy for the listener to understand can be performed. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a sound reproduction device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of input / output level characteristics;

FIG. 3 is a configuration diagram of a sound reproduction device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a sound reproduction device according to a third embodiment of the present invention.

FIG. 5 is a diagram showing an example of a psychological scale relating to sound loudness.

FIG. 6 is a diagram showing an example of an impression input unit.

FIG. 7 is a diagram illustrating an example of input / output level characteristics;

FIG. 8 is a configuration diagram of a conventional sound reproducing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 audio signal input means 2 band pass filter 3 level detection means 4 amplitude control means 5 adder 6 signal generation means 7 level setting means 8 selector 9 amplifier 10 speaker 11 listener 12 remote control 13 reference signal level control means 14 corresponding analysis means 15 Impression input means

Claims (8)

[Claims] A signal generating means for generating a reference signal; a level setting means for setting a minimum audible level by varying a reproduction level of the reference signal; a signal input means for inputting an audio signal; A band-pass filter for dividing the signal into a plurality of bands, a level detecting means for detecting a level of the divided signal, and a minimum audible level set by the level setting means and a level detected by the level detecting means. Amplitude control means for varying the amplitude level of the signal band-divided by the band-pass filter, an adder for synthesizing a plurality of signals amplitude-controlled by the amplitude control means, an output signal of the adder and the signal generation means Selecting means for selecting any one of the output signals of the above. 2. The apparatus according to claim 1, wherein said signal generating means generates a band noise of the same band as the band divided by said band-pass filter or a sine wave of the same frequency as a frequency in the band. Sound reproduction device. 3. A signal generating means for generating a reference signal, a reference signal level control means for automatically controlling a reproduction level of the reference signal, and information as to whether or not the reproduced reference signal can be heard. Level setting means for setting the minimum audible level, signal input means for inputting an audio signal, a band-pass filter for dividing the audio signal into a plurality of bands, and level detection means for detecting the level of the divided signal. Amplitude control means for varying the amplitude level of a signal band-divided by the band-pass filter based on the minimum audible level set by the level setting means and the level detected by the level detection means; and the amplitude control means. An adder for synthesizing a plurality of signals whose amplitudes are controlled by the adder; and one of the output signal of the adder and the output signal of the signal generating means. And a selecting means for selecting a signal. 4. The signal generating means according to claim 3, wherein said signal generating means generates a band noise of the same band as the band divided by said band-pass filter or a sine wave of the same frequency as a frequency in the band. Sound reproduction device. 5. The sound according to claim 3, wherein said reference signal level control means controls the reproduction level of the reference signal from a low level to a high level, from a high level to a low level, or randomly. Playback device. 6. A signal generating means for generating a reference signal, a reference signal level controlling means for automatically controlling a reproduction level of the reference signal, and an impression of a loudness of the reproduced reference signal in a plurality of stages. Correspondence analysis means for inputting a correspondence between a reproduction level and a psychological impression, a signal input means for inputting an audio signal, a band-pass filter for dividing the audio signal into a plurality of bands, Level detection means for detecting a level, and amplitude control for varying the amplitude level of the signal band-divided by the band-pass filter based on the correspondence set by the correspondence analysis means and the level detected by the level detection means Means, an adder for synthesizing a plurality of signals whose amplitudes have been controlled by the amplitude control means, and one of an output signal of the adder and an output signal of the signal generating means. A sound reproducing apparatus comprising: selecting means for selecting the signal of (i), and impression input means for inputting an impression of a sound volume to be actually reproduced. 7. The signal generating means according to claim 6, wherein said signal generating means generates a band noise of the same band as the band divided by said band-pass filter or a sine wave of the same frequency as a frequency in the band. Sound reproduction device. 8. The sound according to claim 6, wherein said reference signal level control means controls the reproduction level of the reference signal from a low level to a high level, from a high level to a low level, or randomly. Playback device.