Voice correction device

Abstract

The present invention prevents a device having a voice clarification function such as a hearing aid worn by a hearer from causing a failure even if a voice of excessive volume is generated when a speaker utters a voice.　A voice correction device (1) comprises: a voice voltage divider (11) that voltage-divides a voice signal representing a collected voice into a first voice signal and a second voice signal; an output terminal (12) that outputs the second voice signal; a DC conversion unit (14) that is connected to the voice voltage divider via a first resistor (13) and converts AC voltage of the first voice signal applied via the first resistor into DC voltage; a switch element (15) that is brought into a conducting state when the DC voltage becomes equal to or higher than a predetermined value; and an attenuator (16) that is connected to the voice voltage divider and attenuates the second voice signal to be supplied to the output terminal when the switch element has been brought into the conducting state.

Description

Voice correction device

[0001] The present invention relates to a voice correction device.

[0002] Conventionally, various techniques for clarifying voices have been proposed. For example, Patent Document 1 describes a hearing aid including a first means for generating a control signal and a second means for performing amplification. The first means frequency-analyzes an acoustic signal that changes with time to obtain, in real time, a signal in the frequency band with the highest level, and generates a control signal for increasing the gain of signals in a high-frequency range compared to the signal in the frequency band with the highest level. The second means receives the control signal from the first means, changes its frequency characteristics, and performs amplification by increasing the gain of signals in a high-frequency range compared to the signal in the frequency band with the highest level.

[0003] Japanese Patent Application Laid-Open No. 2001-157299

[0004] In daily life, sounds such as when a door opens and closes, the sound of a public transportation vehicle passing by, impact sounds and breaking sounds caused by an object falling, etc., may suddenly generate voices with excessive volumes compared to conversations. Also, in an event venue where many people gather, voices with excessive volumes are constantly generated. Therefore, when having a conversation with a partner through the above hearing aid, there was a possibility of problems occurring when voices with excessive volumes as described above from the surroundings of the partner were input together with the voice of the partner. The problems include the hearing aid outputting the voice with excessive volume as it is, outputting the voice without clarifying it, etc.

[0005] One aspect of the present invention has been made in view of the above problems, and an object thereof is to provide a technique for preventing a device having a voice clarification function such as a hearing aid worn by a listener from malfunctioning even when a voice with an excessive volume is generated when a speaker emits a voice.

[0006] To solve the above problems, an audio correction device according to one aspect of the present invention comprises: an audio voltage divider that divides an audio signal representing collected sound into a first audio signal and a second audio signal; an output terminal that outputs the second audio signal; a DC conversion unit connected to the audio voltage divider via a first resistor and converting the AC voltage of the first audio signal applied via the first resistor into a DC voltage; a switch element that becomes conductive when the DC voltage exceeds a predetermined level; and an attenuator connected to the audio voltage divider that attenuates the second audio signal supplied to the output terminal when the switch element becomes conductive.

[0007] According to one aspect of the present invention, even if the speaker produces excessively loud sounds when emitting speech, a device with a speech clarity function, such as a hearing aid worn by the listener, can be prevented from malfunctioning.

[0008] This is a circuit diagram showing the configuration of an audio correction device according to an embodiment of the present invention. This is a graph comparing the input and output of audio signals by a conventional device with the input and output of audio signals by the audio correction device according to this embodiment.

[0009] One embodiment of the present invention will be described in detail below.

[0010] [Configuration of the Audio Correction Device 1] As shown in Figure 1, the audio correction device 1 includes an audio voltage divider 11, an output terminal 12, a first resistor 13, a DC converter 14, a switch element 15, and an attenuator 16. The audio correction device 1 according to this embodiment further includes an audio amplifier 17 (third amplifier), an impedance converter 18, and an audio corrector 19.

[0011] The audio amplifier 17 amplifies the audio signal representing the collected sound. In this embodiment, the audio amplifier 17 is connected to the sound-collecting microphone 2. That is, the audio amplifier 17 amplifies the audio signal representing the sound collected by the sound-collecting microphone 2. Note that the audio amplifier 17 may not amplify the audio signal at all frequencies, but rather be configured to amplify the components of the audio signal in the range of several tens of hertz to 10 kilohertz.

[0012] [Voltage Divider 11] The voltage divider 11 divides the audio signal representing the collected sound into a first audio signal and a second audio signal. As described above, the audio correction device 1 according to this embodiment is equipped with an audio amplifier 17. Therefore, the voltage divider 11 according to this embodiment divides the audio signal amplified by the audio amplifier 17 into a first audio signal and a second audio signal.

[0013] [Output terminal 12] Output terminal 12 outputs the second audio signal.

[0014] [First Resistor 13] The first resistor 13 is interposed between the audio voltage divider 11 and the DC conversion unit 14. The first resistor 13 in this embodiment is configured so that its resistance value can be set to any desired resistance value. The magnitude of the DC voltage, which will be described later, is determined by the resistance value of the first resistor 13. Therefore, by making the resistance value of the first resistor 13 variable, the level of the audio signal required for the DC voltage to exceed a predetermined level can be set to any desired level.

[0015] [DC Conversion Unit 14] The DC conversion unit 14 is connected to the audio voltage divider 11 via the first resistor 13 and converts the AC voltage of the first audio signal applied via the first resistor 13 to a DC voltage. The DC conversion unit 14 according to this embodiment includes a control signal amplifier 141 (first amplifier), a DC / AC conversion amplifier 142 (second amplifier), a rectifier 143, and a smoothing capacitor 144.

[0016] (Control signal amplifier 141) The control signal amplifier 141 has an amplifier input terminal 141a connected to the first resistor 13, and an amplifier output terminal 141b connected to the first input terminal 142a of the DC / AC conversion amplifier 142.

[0017] (DC / AC conversion amplifier 142) The DC / AC conversion amplifier 142 has its second input terminal 142b connected to the first terminal 15a of the switch element 15, and its output terminal 142c connected to the rectifier input terminal 143a (anode) of the rectifier 143.

[0018] (Rectifier 143) The rectifier 143 has its rectifier output terminal 143b (cathode) connected to the control terminal 15c of the switch element 15.

[0019] (Smoothing Capacitor 144) The smoothing capacitor 144 is interposed between the rectifier output terminal 143b of the rectifier 143 and the first terminal 15a of the switching element 15. The smoothing capacitor 144 suppresses the ripple of the current rectified by the rectifier 143 and smooths it out.

[0020] [Switching element 15] The switching element 15 is interposed between the attenuator 16 and the DC conversion unit 14. The switching element 15 becomes conductive (ON) between the first terminal 15a and the second terminal 15b when the DC voltage exceeds a predetermined level. In this embodiment, the switching element 15 is configured to become conductive when a DC voltage of a predetermined level (e.g., 0.6V) or higher is applied to the control terminal 15c. The switching element can be made of a semiconductor element such as a transistor.

[0021] [Attenuator 16] The attenuator 16 is connected to the audio voltage divider 11 and attenuates the second audio signal supplied to the output terminal 12 when the switch element 15 becomes conductive. The attenuator 16 according to this embodiment includes a main audio series resistor 161 (second resistor) and a main audio setting attenuation resistor 162 (third resistor).

[0022] (Main audio series resistor 161) The main audio series resistor 161 has one end connected to the audio voltage divider 11 and the other end connected to the output terminal 12. In this embodiment, the other end of the main audio series resistor 161 is connected to the output terminal 12 via an impedance converter 18.

[0023] (Main audio setting attenuation resistor 162) One end of the main audio setting attenuation resistor 162 is connected to the other end of the main audio series resistor 161, and the other end is connected to the second terminal 15b of the switch element 15. By adjusting the resistance value of the main audio setting attenuation resistor 162, the second audio signal can be attenuated to any desired level.

[0024] [Impedance Converter 18] The impedance converter 18 is interposed between the attenuator 16 and the output terminal 12. This allows the impedance upstream of the impedance converter 18 to be matched with the impedance on the audio corrector 19 side.

[0025] [Sound Corrector 19] The sound corrector 19 is connected to the output terminal 12 and clarifies specific components included in the second sound signal. Various conventionally known techniques (for example, the techniques described in Patent Document 1 (Japanese Patent Application Publication No. 2001-157299), Japanese Patent Application Publication No. 2021-108429, etc.) can be used to clarify the sound using the sound corrector 19. In this embodiment, the sound corrector 19 is connected to the speaker 3. Therefore, the sound based on the clarified second sound signal output by the sound corrector 19 is emitted from the speaker 3.

[0026] [Effects of the Voice Correction Device 1] The voice correction device 1 described above works as follows: when a voice signal having a level above the level required for the DC voltage to be above a predetermined level (operation start level), as defined by the resistance value of the first resistor 13, is input, the switch element 15 becomes conductive. Then, the second voice signal, which is obtained by voltage division from the voice signal, is attenuated by the attenuator 16, and the attenuated second voice signal is output from the output terminal 12. Therefore, with the voice correction device 1, even if the speaker produces excessively loud sounds when speaking, it is possible to prevent malfunctions (such as outputting excessively loud sounds as they are, or outputting sounds without clarification) in devices with a voice clarification function, such as hearing aids worn by the listener (in this embodiment, the voice corrector 19).

[0027] Specifically, in the case of a device in which the sound-collecting microphone 2 is directly connected to the sound corrector 19 (and does not have the function to attenuate excessive sound according to the present invention), as shown in the upper left and lower left graphs of Figure 2, for example, as the level of the input sound signal increases, the level of the output sound signal also increases without limit. In contrast, in the sound correction device 1 according to this embodiment, as shown in the upper right and lower right graphs of Figure 2, for example, even if the level of the input sound signal increases, the level of the second sound signal output for sound signals above the operating start level does not increase above a certain level (control range).

[0028] Such effects contribute, for example, to achieving Goal 3 of the United Nations' Sustainable Development Goals (SDGs), "Ensure healthy lives and promote well-being for all."

[0029] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. For example, in the above embodiment, a voice correction device 1 with a built-in voice corrector 19 was illustrated, but the voice corrector may be configured to be externally attached to the voice correction device. Conversely, in the above embodiment, a voice correction device 1 with an externally attached sound-collecting microphone 2 was illustrated, but the sound-collecting microphone may be configured to be built into the voice correction device.

[0030] [Summary] The audio correction device according to embodiment 1 of the present invention comprises: an audio voltage divider that divides an audio signal representing collected audio into a first audio signal and a second audio signal; an output terminal that outputs the second audio signal; a DC conversion unit connected to the audio voltage divider via a first resistor and converting the AC voltage of the first audio signal applied via the first resistor into a DC voltage; a switch element that becomes conductive when the DC voltage exceeds a predetermined level; and an attenuator connected to the audio voltage divider that attenuates the second audio signal supplied to the output terminal when the switch element becomes conductive.

[0031] The audio correction device according to embodiment 2 of the present invention may be configured such that, in embodiment 1 above, the DC conversion unit comprises a first amplifier, a second amplifier, a rectifier, and a smoothing capacitor, the input terminal of the first amplifier is connected to the first resistor and the output terminal is connected to the input terminal of the second amplifier, the first output terminal of the second amplifier is connected to the input terminal of the rectifier and the second output terminal is connected to the attenuator via the switch element, and the output terminal of the rectifier is connected to the control terminal of the switch element and the second output terminal of the second amplifier via the smoothing capacitor.

[0032] In the third aspect of the present invention, the audio correction device may be configured such that, in the first aspect 1 or 2 described above, the first resistor is configured to allow the resistance value to be set to any arbitrary resistance value.

[0033] The audio correction device according to embodiment 4 of the present invention may be configured such that, in any one of embodiments 1 to 3 above, the attenuator comprises a second resistor and a third resistor, the second resistor having one end connected to an audio voltage divider and the other end connected to the output terminal, and the third resistor having one end connected to the other end of the second resistor and the other end connected to the switch element.

[0034] The audio correction device according to embodiment 5 of the present invention may further include a third amplifier for amplifying the audio signal, and the audio voltage divider may be configured to divide the amplified audio signal into a first audio signal and a second audio signal.

[0035] The audio correction device according to embodiment 6 of the present invention may further include an impedance converter interposed between the second resistor and the output terminal, as described in any one of embodiments 1 to 5 above.

[0036] The audio correction device according to embodiment 7 of the present invention may further include an audio corrector connected to the output terminal and used to clarify specific components contained in the second audio signal, as described in any one of embodiments 1 to 6 above.

[0037] 1. Audio Correction Device 11. Audio Voltage Divider 12. Output Terminal 13. Resistor (First Resistor) 14. DC Conversion Unit 141. Control Signal Amplifier 141a. Amplifier Input Terminal 141b. Amplifier Output Terminal 142. DC / AC Conversion Amplifier 142a. First Input Terminal 142b. Second Input Terminal 142c. Output Terminal 143. Rectifier 143a. Rectifier Input Terminal 143b. Rectifier Output Terminal 144. Smoothing Capacitor 15. Switching Element 15a. First Terminal 15b. Second Terminal 15c. Control Terminal 16. Attenuator 161. Main Audio Series Resistor (Second Resistor) 162. Main Audio Setting Attenuation Resistor (Third Resistor) 17. Audio Amplifier 18. Impedance Converter 19. Audio Corrector 2. Microphone 3. Speaker

Claims

1. A sound correction device comprising: an audio voltage divider that divides an audio signal representing collected sound into a first audio signal and a second audio signal; an output terminal that outputs the second audio signal; a DC converter connected to the audio voltage divider via a first resistor and converting the AC voltage of the first audio signal applied via the first resistor into a DC voltage; a switch element that becomes conductive when the DC voltage exceeds a predetermined level; and an attenuator connected to the audio voltage divider that attenuates the second audio signal supplied to the output terminal when the switch element becomes conductive.

2. The DC conversion unit comprises a first amplifier, a second amplifier, a rectifier, and a smoothing capacitor, wherein the input terminal of the first amplifier is connected to the first resistor and the output terminal is connected to the first input terminal of the second amplifier, the second input terminal of the second amplifier is connected to the attenuator via the switch element and the output terminal is connected to the input terminal of the rectifier, and the output terminal of the rectifier is connected to the control terminal of the switch element and the switch element via the smoothing capacitor, the audio correction device according to claim 1.

3. The audio correction device according to claim 1, wherein the first resistor is configured to allow the resistance value to be set to any arbitrary resistance value.

4. The attenuator comprises a second resistor and a third resistor, wherein one end of the second resistor is connected to an audio voltage divider and the other end is connected to the output terminal, and one end of the third resistor is connected to the other end of the second resistor and the other end is connected to the switch element, the audio correction device according to claim 1.

5. The audio correction device according to claim 1, further comprising a third amplifier for amplifying the audio signal, wherein the audio voltage divider divides the amplified audio signal into a first audio signal and a second audio signal.

6. The audio correction device according to claim 1, further comprising an impedance converter interposed between the attenuator and the output terminal.

7. The audio correction device according to any one of claims 1 to 6, further comprising an audio corrector connected to the output terminal for clarifying specific components included in the second audio signal.

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