JP2010191302A - Voice-outputting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voice-outputting device that includes a means for reducing inconvenience as much as possible, wherein the inconvenience in which "a voice outputted will be unnatural" occurs when the upper localization of the voice and the clarity in the voice are improved by using a conventional technology. <P>SOLUTION: The voice-outputting device amplifies signal intensity by a uniform increase rate with regard to frequency components lower in intensity than a predetermined threshold when subjecting voice signals to be outputted to a process for emphasizing formant greater than a second formant, thereby making, as much as possible, an intensity balance of the voice signal in respective frequency components after performing the emphasis process equal to the intensity balance of the voice signal in respective frequency component before performing the emphasis process. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an audio output device installed in a television or a theater rack.

  The audio output together with the video displayed on the display of the television is output via speakers provided on both sides or the lower side of the television, or is output via speakers of a theater rack used together with the television.

  Generally, a theater rack is installed under the television. In such a case, the sound output from the speaker of the theater rack is heard from the lower side than the image displayed on the television screen, which gives the viewer a sense of discomfort. A similar problem may occur in a television provided with a speaker on the lower side of the screen.

  In addition, a speaker provided in a television is often installed with a relatively small speaker because of its configuration. However, when outputting sound through a small speaker, if the sound is output at a low volume, the clarity is deteriorated. Problems can arise.

  Here, as a technique capable of solving the problem that “sound can be heard from below the video projected on the television screen”, there is a technique disclosed in Patent Document 1. Specifically, using the well-known fact that “sound near 8 kHz feels as if it is heard from above”, the component near 8 kHz in the output sound is emphasized, so that the sound is localized upward. is there.

  In addition, as a technology that can solve the problem of “intelligibility of the output speech is poor”, the output is performed using the well-known fact that “intelligibility higher than the second formant improves speech intelligibility”. A technique is known that enhances the intelligibility of speech by performing formant peak enhancement processing on the speech.

5-43700

  However, when the conventional technology as described above is used, the output audio signal is deformed from the original one, which may result in unnatural audio. For example, a high-wavelength component is emphasized, resulting in a voice that is difficult for humans to hear. In other words, using the conventional technology, the process of emphasizing the component near 8 kHz of the audio signal to be output is performed, or the formants higher than the second formant (second formant, third formant, fourth formant ...) are emphasized. Even if the processing to perform the above is performed, other problems such as an unnatural voice that is difficult for the viewer to hear can be caused even if the sound can be localized and improved in clarity. Conventionally, there has been no technology that can solve the above-mentioned two problems at the same time.

  Therefore, in the present invention, it is possible to have an inconvenience that “the output sound becomes unnatural sound” that may occur when the conventional technology is used to realize the upward localization of the sound and the improvement of the intelligibility of the sound. It is an object of the present invention to provide an audio output device including means for reducing as much as possible. It is another object of the present invention to provide an audio output device that can solve the above-mentioned two problems at the same time.

  As a means for solving the above-mentioned problem, in the present invention, when performing a process of emphasizing a formant greater than or equal to the second formant for an audio signal to be output, the frequency component having an intensity lower than a predetermined threshold is uniformly raised, An audio output device that amplifies signal strength is provided.

  In this way, it is possible to make the intensity balance of the audio signal of each frequency component after the enhancement process as close as possible to the intensity balance of the audio signal of each frequency component before the enhancement process. In addition, by using a predetermined threshold value that is specified so as to specify a formant equal to or higher than the second formant, components in the vicinity of 7 to 8 kHz are inevitably specified, and these components are also subjected to enhancement processing. To achieve the upper localization of the voice.

  Furthermore, it amplifies each frequency component of the audio signal according to the attributes (news, drama, etc.) of the content (TV broadcast program, etc.) output from the TV and the viewing mode (night mode, cinema mode, etc.) selected by the user. Provide an audio output device having a function for performing processing such as compression. In this way, the frequency component that emphasizes the signal strength is reduced as much as possible, and the audio signal of each frequency component before the enhancement process and the audio signal of each frequency component after the enhancement process are made as equal as possible. Has realized that.

  With the audio output device of the present invention, it is possible to reduce the inconvenience that the output audio becomes unnatural audio as much as possible, and to realize the upward localization of the audio and the improvement of the intelligibility of the audio. In addition, by one process of amplifying the signal strength with respect to a frequency component having a signal strength lower than a predetermined threshold, it is possible to simultaneously solve the sound localization and the improvement of the speech clarity.

Schematic for explaining formants Functional block diagram of the audio output device of Embodiment 1 Example of hardware diagram of audio output device of embodiment 1 The flowchart which shows an example of the flow of a process of the audio | voice output apparatus of Embodiment 1. FIG. Functional block diagram of the audio output device of the second embodiment

Examples of the present invention will be described below. The relationship between the embodiments and the claims is as follows. The first embodiment mainly relates to claims 1, 4, 5 and the like, and the second embodiment mainly relates to claims 2, 3, etc. In addition, this invention is not limited to these Examples at all, and can be implemented in various modes without departing from the gist thereof.
<< Embodiment 1 >>
<Outline of Embodiment 1>

  When the audio output device according to the present embodiment acquires an audio signal, the audio output device performs a process of amplifying the signal intensity on a frequency component having a signal intensity lower than a predetermined threshold. Further, bass correction processing is performed as necessary. Then, the processed audio signal is output through a speaker or the like.

For example, assume that an audio signal as shown in FIG. 1 is acquired. In the figure, an audio signal at a certain moment is shown with “output amplitude (dB: decibel)” on the vertical axis and “frequency (Hz: hertz)” on the horizontal axis. When the audio signal as shown in the figure is acquired, the audio output device according to the present embodiment specifies a frequency component having a signal intensity lower than a predetermined threshold, and the audio signal having the specified frequency component has the same width ( Example: Amplification is performed at 3 dB). Further, in order to perform bass correction, a part of the low frequency component audio signal is amplified or a part of the high frequency component audio signal is compressed as necessary. Thereafter, the processed audio signal is output through a speaker or the like.
<Functional configuration of Embodiment 1>

  An example of functional blocks of the audio output device of the present embodiment is shown in FIG. As shown in FIG. 2, the “audio output device” (0200) of the present embodiment includes an “audio signal acquisition unit” (0201), a “threshold holding unit” (0202), and an “amplification unit” (0203). , “Audio output unit” (0205). In addition, you may have a "reduction part" (0204).

  Here, the functional blocks of the present device (sound output device) can be realized as hardware, software, or both hardware and software. Specifically, if a computer is used, a CPU, a RAM, a bus, or a secondary storage device (a storage medium such as a hard disk, a non-volatile memory, a CD-ROM or a DVD-ROM, and a read drive for the medium) ), Hardware components such as printing devices, display devices, and other external peripheral devices, I / O ports for the external peripheral devices, driver programs for controlling these hardware, other application programs, and information input User interface.

  In addition, these hardware and software process the program developed on the RAM with the CPU, and process, store, and output data stored on the memory and hard disk, data input via the interface, etc. It is used for processing or controlling each hardware component. In addition, the present invention can be realized not only as an apparatus but also as a method. A part of the invention can be configured as software. Furthermore, a software product used for causing a computer to execute such software, and a storage medium in which the product is fixed to a storage medium are naturally included in the technical scope of the present invention (the same applies throughout this specification). Is).

  Hereinafter, “audio signal acquisition unit” (0201), “threshold holding unit” (0202), “amplification unit” (0203), and “reduction unit” (0204) of the “audio output device” (0200) of this embodiment. The functional configuration of the “voice output unit” (0205) will be described in detail.

  The “audio output device” (0200) is configured to output audio by performing AD / DA conversion, decoding processing, amplification processing, and the like as necessary when an audio signal is acquired. Note that the above-described processing is not necessarily indispensable for the audio output device (0200) of the present embodiment, and differs depending on the type of audio signal to be acquired (digital signal, analog signal, etc.). The audio output device (0200) of this embodiment can be used for any device that outputs audio, such as a television, a theater rack, a personal computer, and a radio.

  The “audio signal acquisition unit” (0201) is configured to acquire an audio signal. As the means, a means for acquiring a digital audio signal provided with an optical input, an HDMI input, etc., or acquiring a digital audio signal or an analog audio signal from a broadcast wave acquired via a TV tuner, etc. can be considered. Note that the above is merely an example, and an audio signal may be acquired by other means.

  The “threshold holding unit” (0202) is configured to hold a threshold used to specify a formant equal to or higher than the second formant of the human voice in the audio signal. A “formant” is a unique frequency spectrum possessed by a human voice and varies depending on gender, age, and the like. However, in general, the frequency spectrum of a human voice has a plurality of peaks, and the signal intensity of these peaks tends to become weaker as the frequency becomes higher. And from the low frequency peak to the high frequency peak, they are called “first formant”, “second formant”,. The “formant above the second formant” is a formant other than the first formant, and specifically, the second formant, the third formant, the fourth formant, and so on.

  Here, the “threshold value” held by the threshold value holding unit (0202) is used to specify a frequency component having a signal strength lower than the threshold value in the audio signal acquired by the audio signal acquisition unit (0201). That is, the value of “threshold value” is indicated by signal strength (sound signal amplitude: dB). Although the threshold value is an arbitrary design item, when a frequency component having a signal strength lower than the threshold value in the acquired audio signal is specified, the formant frequency equal to or higher than the second formant is included in the specified frequency component. To be included. For example, in the case of television broadcast content received via a television tuner, “−16 to −20 dB” may be determined. In the case of content acquired from a recording medium such as a DVD or Blu-ray, “−20 to −25 dB” may be determined. In addition, the acquired audio signal may be used, and the threshold value may be calculated by calculation processing each time and temporarily stored.

  Note that the threshold holding unit (0202) does not have to be limited to one threshold, and a plurality of thresholds may be held for each content format. In such a case, each threshold value may be stored in association with each format, and a threshold value to be compared with the acquired audio signal may be selected according to the format of the acquired content.

  The “amplifying unit” (0203) is configured to amplify the signal strength with respect to a frequency component having a signal strength lower than the threshold value. That is, the amplifying unit (0203) compares the audio signal acquired by the audio signal acquiring unit (0201) with the threshold value held by the threshold value holding unit (0202), and calculates a frequency component having a signal intensity lower than the threshold value. Identify. Then, a process for amplifying the signal intensity is performed on the identified frequency component. By this processing, the formant frequency component equal to or higher than the second formant is amplified. Note that the amplification unit (0203) is realized by a DSP (Digital Signal Processor) or the like. Further, the amplifying width (raised width) is an arbitrary design item determined in advance, and may be determined to be 3 dB, 5 dB, or the like, for example.

  Here, it is known that when a formant speech signal equal to or higher than the second formant is emphasized, the clarity of speech is improved. That is, by the amplification processing of the amplification unit (0203), it is realized to improve the clarity of the sound output from the sound output device (0200).

  In general, the frequency of the second formant appears in the vicinity of 800 to 2500 Hz (depending on gender, age, physique, etc.). Therefore, when an amplification process is performed on a frequency component having a signal intensity lower than a predetermined threshold, a frequency component of 7 to 8 kHz is inevitably amplified.

  Here, it is known that the sound of the frequency component near 7 to 8 kHz is localized upward. That is, by the amplification process of the amplification unit (0203), the frequency component in the vicinity of 7 to 8 kHz is emphasized, and the upper localization of the sound output from the sound output device (0200) is also realized.

  It is desirable that the amplification process of the amplification unit (0203) amplifies all the specified frequency components uniformly with the same increase width. By doing so, the intensity balance of the audio signal of each frequency component after amplification processing is made equal to the intensity balance of the audio signal of each frequency component before amplification processing in all the specified frequency components. Is possible. That is, the amplification process can reduce the output sound from becoming unnatural.

  The “reducing unit” (0204) is configured to reduce (compress) the audio signal intensity of the high frequency component. By the processing of the reduction unit (0204), it is possible to eliminate “sound unnaturalness due to amplification of a high-frequency component audio signal by the amplification processing of the amplification unit (0203)”. Specifically, which frequency component is reduced is an arbitrary design matter. Further, the compression width (lowering width) is also an arbitrary design matter. For example, when the amplification unit (0203) uniformly amplifies all the frequency components specified by using the threshold value by 3 dB, the constant high frequency component in the frequency component may be compressed by 1 dB. Good. The reduction unit (0204) is realized by a DSP or the like having a function of PEQ (Paramic Equalizer).

  In addition, by amplifying the sound signal intensity of the low frequency component, the unnaturalness of the sound due to the amplification of the sound signal of the high frequency component by the amplification process in the amplification unit (0203) may be eliminated. . Here, the low frequency component may be a part or all of the frequency components in the frequency component having a signal strength equal to or higher than the threshold held by the threshold holding unit (0202).

  The “audio signal output unit” (0205) is configured to output an amplified audio signal. The audio signal output unit (0205) is realized by a speaker or the like.

In the above description, the acquired audio signal is an audio signal of a human voice. However, the same processing is performed when acquiring an audio signal such as an instrument sound or an animal voice. It is possible to achieve the same effect.
<Hardware Configuration of Embodiment 1>

  FIG. 3 is a diagram illustrating an example of a configuration when the above-described functional configuration of the audio output device of the present embodiment is realized as hardware.

  Hereinafter, an example of means for realizing the present embodiment will be described with reference to the hardware diagram of FIG.

  The control unit (0301) controls the input selector switch (0303) to acquire an analog audio signal or a digital audio signal. The analog audio signal is converted into a digital audio signal by an ADC (Analog Digital Converter: 0302) and sent to the DSP (0304).

  Further, the control unit (0301) controls the DSP (0304) so as to amplify the signal intensity at a predetermined amplification level with respect to a frequency component having a signal intensity lower than a predetermined threshold. The DSP (0304) amplifies the acquired digital audio signal according to the control of the control unit (0301).

  Further, the control unit (0301) controls the DSP (0305) so as to compress the signal strength at a predetermined compression level for the audio signal having a predetermined high frequency component. In addition, the DSP (0305) is controlled so as to amplify the signal intensity at a predetermined amplification level for the audio signal having a predetermined low frequency component. The DSP (0305) amplifies and / or compresses the acquired digital audio signal according to the control of the control unit (0301).

Thereafter, the amplified and / or compressed digital audio signal is converted into an analog audio signal by a DAC (Digital Analog Converter: 0306), amplified by an AMP (amplifier: 0307), and sent to a speaker (0308). Then, the speaker (0308) outputs a sound that realizes the upward localization and the improvement of the clarity without becoming unnatural sound at the same time.
<Processing flow of Embodiment 1>

  An example of the processing flow of the audio output device of this embodiment is shown in the flowchart of FIG.

  First, when the audio output device acquires an audio signal (S0401), the frequency component having a signal intensity lower than the threshold is specified using a threshold value held in advance, and the signal intensity is amplified with respect to the specified frequency component. (S0402).

Thereafter, the signal strength of the high frequency component is reduced (compressed) (S0403), and the sound is output using the sound signal that has been subjected to the processing such as amplification (S0404). Note that step S0403 may not be executed.
<Effect of Embodiment 1>

With the audio output device according to the present embodiment, it is possible to output a sound in which upward localization / intelligibility is improved and at the same time without becoming unnatural sound.
<< Embodiment 2 >>
<Outline of Embodiment 2>

The audio output device according to the present embodiment has an amplification mode (night mode, cinema mode, drama mode) in which processing details (how to amplify, etc.) of amplification processing for an audio signal to be performed to realize upward localization and the like are patterned. , News mode, etc.). Then, one amplification mode is selected according to the user selection and / or the attribute of the content to be output (news, drama, etc.), and the amplification process for the audio signal is executed according to the processing content defined in the selected amplification mode.
<Functional configuration of Embodiment 2>

  An example of functional blocks of the audio output device of this embodiment is shown in FIG. As shown in FIG. 5, the “audio output device” (0500) of the present embodiment includes an “audio signal acquisition unit” (0501), a “threshold value holding unit” (0502), and an “amplification unit” (0503). , “Audio output unit” (0505), “amplification mode holding unit” (0506), “amplification mode selection unit” (0507), and “amplification control unit” (0508). Furthermore, “selection means” of “reduction unit” (0504) and / or “attribute information acquisition unit” (0509) and “amplification mode selection unit” (0507) may be included.

  Hereinafter, the functional configuration of the “voice output device” (0500) of the present embodiment will be described in detail. Note that portions described in the first embodiment are omitted.

  The “amplification mode holding unit” (0506) is configured to hold a plurality of patterned amplification modes. “Patterning” defines the contents of amplification processing, such as which frequency band components are subjected to amplification processing and / or in what range the amplification processing is performed. The content of the patterned amplification process is not particularly limited, but may be as follows.

  For example, it is considered that news viewers do not have a particular problem even if the position where the sound is output is below the television screen. However, it is thought that the voice clarity is desired. Therefore, as the “news mode”, only the frequency component (about 5 kHz or less) of the voice band is compared with the threshold value, and the frequency component (frequency component having a signal strength lower than the threshold value) specified by the comparison is determined. Only a pattern determined to perform amplification processing (eg, 4 dB amplification) may be held.

  In addition, it is considered that viewers such as dramas and movies feel unnatural if the position where the sound is output is below the TV screen. In addition, it is considered that the intelligibility of voice is desired to be clear. Therefore, in “cinema / drama mode”, all frequency components are compared with a threshold value, and the frequency component (frequency component having a signal intensity lower than the threshold value) specified by the comparison is amplified (eg, A pattern determined to perform (4 dB amplification) may be held.

  In addition, viewers of sports broadcasts such as martial arts and baseball feel unnatural that the position where the sound is output is below the TV screen, but it is considered that there is no problem even if the sound clarity is slightly reduced. Therefore, as a “sport mode”, all frequency components are compared with a threshold value, and a relatively weak amplification process (for example, a frequency component with a signal intensity lower than the threshold value) specified in the comparison (example) : 2dB amplification) and further amplification processing (eg, further 2dB amplification) on the frequency component (about 7-8kHz) that causes the sound to be localized upward, and specified to eliminate the unnaturalness of the sound A pattern that is determined to perform amplification processing on the low frequency component may be held.

  In addition, it is considered that there are many cases in which viewers at night view with lower sound than in the daytime. Therefore, a pattern determined to perform relatively strong amplification processing (eg, 6 dB amplification) may be held as the “night mode”.

  The above is merely an example, and an amplification mode in which other patterns are determined may be held.

  The “amplification mode selection unit” (0507) is configured to select an amplification mode. That is, one amplification mode is selected from a plurality of amplification modes held by the amplification mode holding unit (0506).

  Here, the selection process by the amplification mode selection unit (0507) is performed in one amplification mode according to a selection operation from a viewer using an interface displayed on a display such as a remote control device or a television / PC. A selection process may be performed. Alternatively, a “selection unit” described below may be provided, and selection processing of one amplification mode may be performed by the selection unit.

  The “amplification control unit” (0508) is configured to control the amplification degree of the amplification unit (0503) according to the pattern of the selected amplification mode. That is, the amplifying unit (0503) controlled by the amplifying control unit (0508) operates on the audio signal acquired by the audio signal acquiring unit (0501) according to the amplification mode pattern selected by the amplification mode selecting unit (0507). Thus, amplification processing is performed. By this processing, it is possible to perform amplification processing according to the user's wishes or according to the content attributes.

  The “attribute information acquisition unit” (0509) is configured to acquire attribute information of content including an audio signal from an EPG or the like. Specifically, attribute information related to the audio signal (content) acquired by the audio signal acquisition unit (0501) is acquired. As attribute information to be acquired, information (news, drama, sports, etc.) indicating the genre of content can be considered. The attribute information is an example, and other information may be acquired. The acquired attribute information is used by the selection unit of the amplification mode selection unit (0507) described below to select one amplification mode. The attribute information can be acquired using, for example, EPG. For example, when the CH and the broadcast time of the audio signal (content) acquired by the audio signal acquisition unit are identified, attribute information (genre etc.) is acquired from the EPG using the identified information.

The “selection means” of the “amplification mode selection unit” (0507) is configured to select an amplification mode according to the acquired attribute information. That is, the selecting means selects one amplification mode from among a plurality of amplification modes held by the amplification mode holding unit (0506) using the attribute information acquired by the attribute information acquisition unit (0509). For example, when information indicating the genre of “news” is acquired as attribute information, “news mode” is selected as one amplification mode. The selection process may be realized by holding a table in which the content genre is associated with the amplification mode held by the amplification mode holding unit (0506) in advance and using the table.
<Hardware Configuration of Embodiment 2>

The configuration when the above-described functional configuration of the audio output device of the present embodiment is realized as hardware can be realized according to the audio output device of the first embodiment. Therefore, detailed description here is omitted.
<Processing flow of Embodiment 2>

The processing flow of the audio output method of the audio output device of the present embodiment can be realized according to the audio output method of the audio output device of the first embodiment. Therefore, detailed description here is omitted.
<Effect of Embodiment 2>

  With the audio output device according to the present embodiment, it is possible to adjust the amplification processing for realizing upward localization, improvement of intelligibility, and the like according to the content to be output and user selection.

  As a result, it is possible to adjust the sound suitable for the content attribute and the content viewing situation (ambient environment, time zone, etc.).

  0200: Audio output device, 0201: Threshold holding unit, 0203: Amplification unit, 0204: Reduction unit, 0205: Audio output unit

Claims (5)

An audio signal acquisition unit for acquiring an audio signal;
A threshold value holding unit for holding a threshold value used for identifying a formant equal to or higher than the second formant of the human voice in the audio signal;
An amplifying unit for amplifying the signal strength with respect to a frequency component having a signal strength lower than the threshold;
An audio signal output unit for outputting the amplified audio signal;
An audio output device. An amplification mode holding unit for holding a plurality of patterned amplification modes;
An amplification mode selector for selecting an amplification mode;
An amplification control unit that controls the amplification degree of the amplification unit according to the pattern of the selected amplification mode;
The audio output device according to claim 1, comprising: Having an attribute information acquisition unit for acquiring attribute information of content including an audio signal;
The amplification mode selector
The audio output device according to claim 2, further comprising a selection unit that selects an amplification mode according to the acquired attribute information.   The audio output device according to any one of claims 1 to 3, further comprising a reduction unit that reduces the signal intensity of the high-frequency component.   The voice output device according to any one of claims 1 to 4, wherein a second formant of the sound of a musical instrument is employed instead of the second formant of a human voice.

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