JP2005092021A - Method and device for speaking speed conversion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform speaking speed conversion processing which is free of time deviation in speech stereo signal input. <P>SOLUTION: Provided are an adder which adds inputted speech stereo signals of channels L and R together, a speaking speed conversion processing part which inputs the speech signal made monaural by the adder and performs specified speaking speed conversion, and a distributor which distributes the signal outputted after the speaking speed conversion process by the speaking speed conversion processing part to the speech channels L and R respectively, so that the distributed speech L and R signals are reproduced by a speaker. Speed conversion which is free of time deviation in speech stereo signal input is realized without adding algorithm of mutual time management processing of the inputted speech stereo signals and extra memory. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to speaking speed conversion for controlling speaking speed.

  With the recent increase in broadcasting stations and the opening of digital satellite broadcasting, various types of programs can now be broadcast, which is entertaining viewers. However, some of these programs have spoken announcers and talents that may not be audible to the elderly. As a technique for solving this problem, there has been proposed a digital speech speed conversion device that slows only the speed without changing the pitch due to the advancement of digital technology (see, for example, Patent Document 1).

  Hereinafter, an example of the first prior art in the digital speech rate conversion apparatus will be described with reference to FIG. In FIG. 4, reference numeral 10 is an A / D converter that converts an input voice signal from an analog voice signal to a digital voice signal, 11 is a speech speed conversion unit that converts the digital voice signal, and 12 is speech speed converted. A D / A converter 13 for converting a digital audio signal back to an analog audio signal is a memory configured as a ring memory that temporarily stores an input digitally converted audio digital signal.

  The operation of the speech speed converting apparatus configured as described above will be described. The input audio signal is converted from an analog signal to a digital signal by the A / D converter 10 and input to the speech speed conversion unit 11 for converting the speech speed, and is simultaneously stored in the memory 13 configured as a ring memory. The speech speed conversion unit 11 performs processing such as extraction of a silent section of the input voice digital signal, extraction of a vowel of a pronunciation for speech speed conversion, and the conversation example “that is mine” shown in FIG. As shown in (b), if you simply increase the speaking speed in twice the time, you can add vowels and say, “Sore is so awesome!” Perform a lengthening process. The audio digital signal whose time has been extended is returned from the digital audio signal to the analog audio signal by the D / A converter 12, and a series of speech speed conversion processing is completed. On the other hand, when the speech speed is converted and the time is extended, the memory 13 having a finite memory capacity may overflow so that the read address overtakes the write address. It is the conventional method to try to determine the speech rate conversion rate of the speech rate conversion process while inquiring the remaining amount of the memory 13, and conversely, there is no need to store in the silent period, and at the rising edge of the next speech signal, The head of speech speed conversion is adjusted and the overflow is reduced.

  However, in the conventional configuration, if the sound is a monaural signal, it is easier to hear by converting the speech speed. However, the sound of a recent television broadcast is usually a stereo signal, and when converting the audio stereo signal to the speech speed, it is conventional. Assuming that the two-channel parallel configuration shown in FIG. 6 is assumed as the stereo structure, there is a problem of synchronization shift. That is, considering the speech speed conversion when the speech stereo signal shown in FIG. 5 (c) is input to the speech speed conversion device of FIG. 6, the R channel sound is timed after the L channel sound is finished at time t1. When speaking is started at t2, when the speech speed is converted, as shown in FIG. 5 (d), the R channel speech that has been waiting in the silent section is converted to speech speed at time t2 even though the L channel speech is delayed until time t3. , And there is a problem of synchronization error such that time overlap occurs between time t2 and time t3.

  As a technique for solving this problem, an audio stereo signal is added, a silence interval is detected from the added audio signal, and silence intervals of the L channel audio and the R channel audio are deleted, respectively, and the L channel and the R channel are synchronized. A speech speed conversion device has been proposed (see, for example, Patent Document 2).

  Hereinafter, an example of the second prior art in the speech speed conversion device will be described with reference to FIG. In FIG. 7, reference numeral 20 is a hard disk drive as a recording medium for video and audio signals, 21 is a frame memory for storing video and audio data read from the hard disk drive 20, and 22 is a video and audio signal separated. 23, a signal adding unit for adding the separated audio stereo signals, 24 for a pitch period calculating unit for detecting the pitch period for speech speed conversion, and 25 for having an added audio signal for one frame. A section determining unit that determines whether the section is a sound section or a silent section, 26 is a silent section deleting unit that deletes both the L channel sound and the R channel sound of the section determined by the section determining unit 25 as a silent section, and 27 is a pitch cycle unit A time axis compression / decompression unit that performs time axis compression / decompression processing, 28 is a voice memory that stores time-axis compressed / expanded voice data, and 29 is a voice memo 28, the storage rate calculation for performing speech speed conversion control, the speech speed control unit, 30 is an L / R separation unit that separates the speech LR data that is sequentially read from the speech memory 28, and 31 is the LR separation. A D / A converter that converts an L channel audio signal from digital to analog among the audio signals, and 32 is a D / A converter that converts an R channel audio signal from digital to analog among the LR separated audio signals. It is.

The operation of the second conventional speech speed converting apparatus configured as described above will be described. A video signal and an audio signal transmitted by digital television broadcasting or the like are demodulated and recorded in the hard disk drive 20. The recorded video signal and audio signal are read into the frame memory 21 in units of frames and separated into a video signal and an audio signal by the signal distribution unit 22. The separated audio LR signals are sequentially added by the signal adder 23, and an added signal is output when the audio signals for one frame of both channels are added. The section determination unit 25 detects the signal level of the signal for one frame that is added and output, determines whether it is a voiced section or a silent section, controls the silent section deletion unit 26, and if it is a silent section, Both L-channel audio and R-channel audio for one frame are deleted. In this way, synchronization in frame units is maintained. However, the L channel sound and the R channel sound are independent of each other. Next, the pitch period is calculated by the pitch period calculation unit 24, and the time axis compression / expansion is performed using the same pitch period, thereby maintaining the synchronization of the audio L channel and R channel after the time axis compression / expansion. Time compression / decompression processing is possible. The audio data subjected to time-axis compression / expansion is recorded in the audio memory 28, sequentially read out, and an L / R separation unit 30 for separating the audio LR data, and a D / A converter for converting the L channel audio signal from digital to analog. 31. The audio signal of the R channel is reproduced with two analog channels through a D / A converter 32 for converting the digital signal into an analog signal. Further, the storage rate calculation / speech rate control unit 29 that calculates the data storage rate of the voice memory 28 and performs speech speed conversion control does not delete the silent section if the storage rate is low, or conversely, if the storage rate is high, the compression is performed. This is a method for converting the speech speed at the time of fast listening.
JP-A-7-192392 JP 2002-297200 A

  However, when converting the speech speed of the audio stereo signal, if the two channels are simply processed in parallel as in the first prior art configuration, the L channel audio and the R channel audio cannot be synchronized in time, and an overlap period is generated. In order to prevent this overlap, it is necessary to add an algorithm for mutual time management processing of the L channel and the R channel and to add an LR independent audio memory as in the configuration of the second prior art. become.

  In order to solve the above-mentioned problem, the speech speed conversion method of the present invention is characterized in that the input voice stereo signals of a plurality of channels, for example, L channel and R channel, are added and the speech speed is converted with a monaural signal. Is.

  Further, as a speech speed conversion device, an adder for adding the input L-channel and R-channel audio stereo signals, and a speech speed conversion for performing a predetermined speech speed conversion by inputting the audio signal that has become a monaural signal by the adder. A processing unit and a distributor that distributes the output signal of the speech speed conversion processing unit to the L channel and the R channel, respectively, and outputs the result as a speech LR signal. The speech LR signal that has been subjected to speech speed conversion and distribution is output by a speaker or an earphone. It is configured to reproduce.

  By providing the above configuration, the present invention can prevent the overlap of the L channel sound and the R channel sound that are generated when time synchronization is not achieved in the case of the speech speed conversion processing of the sound stereo signal, and the L channel, The speech speed can be converted with a simple circuit configuration without adding an R channel mutual time management processing algorithm and accompanying memory.

(Embodiment 1)
The first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a block diagram showing the configuration of the speech rate conversion apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 is an adder for adding input L channel and R channel audio stereo signals, and 2 is an audio signal that has been converted to a monaural signal by the adder 1, and performs predetermined speech speed conversion. The speech speed conversion processing unit 3 is a distributor that performs speech speed conversion processing by the speech speed conversion processing unit 2 and distributes the output signals to the L channel and the R channel, respectively, and outputs them as audio LR signals. The audio LR signal distributed in (1) is reproduced by speakers of the L channel and the R channel. Note that the audio LR signal is obtained by distributing a monaural signal subjected to speech speed conversion as a signal having the same information in the L channel and the R channel.

  The operation and details of each part of the speech speed converting apparatus configured as described above will be described. For example, in audio reproduction by a television receiver, audio signals detected as L-channel and R-channel audio stereo signals are added by an adder 1 and converted to a monaural signal. For example, if the adder 1 handles digital signals, the adder 1 can be easily configured with an adder and a latch that takes timing of both channels. If an analog signal is handled, the adder 1 can be easily configured using a resistor network or the like. The configuration is not limited as long as audio information of a plurality of channels is added and converted into a monaural signal.

  Next, the monaural signal output from the adder 1 is input, and the speech speed conversion processing unit 2 performs a predetermined speech speed conversion process. Details of the speech speed conversion process will be described below with reference to FIG.

  As shown in Fig. 2 (a), if there are conversations on the L channel and the R channel, that is "I am" and "No, it is", the output of the adder 1 is converted to a monaural signal. As shown in FIG. 2 (b), it is converted to a monaural signal that retains the temporal correspondence in the conversation between the L channel and the R channel, such as "That's mine.

  As an example of the speech speed conversion processing in the speech speed conversion processing unit 2, first, processing such as extraction of a silent section of an input monaural signal, extraction of a vowel of pronunciation for speech speed conversion, and the like is performed. For example, assuming that the conversion rate is converted to a speech speed of twice the time, processing is performed to add a vowel to the conversation section excluding the silent section and extend it to twice the time. The processing result is shown in FIG.

  As shown in the processing result of FIG. 2C, the end time of the conversation portion of the L channel is from t1 to t3, and the time is extended. The start time of the conversation part of the R channel is also shifted from t2 to t3. As a result, it can be seen that the conversation portion of the R channel does not overlap with the conversation portion of the L channel, and acceleration conversion is performed while maintaining temporal correspondence in the conversation.

  Next, the signal output from the speech speed conversion unit 1 is distributed as an audio LR signal to the L channel and the R channel by the distributor 3. The distributor 3 may be configured to flow the same audio information to both channels if it handles digital signals, and may be configured to flow the same signal to both channels by resistance division or the like if it handles analog signals. The configuration is not limited as long as the function is satisfied.

  Further, the speech LR signal which has been converted after the speech speed is supplied to a circuit for reproducing a speaker, for example, an amplifier circuit, and is reproduced by a speaker built in the television receiver so that the television can be viewed.

  As described above, according to the speech speed converting apparatus of the present invention, the speech stereo signal of L channel and R channel can be simply added and the speech without a time shift when the audio stereo signal is input. High-speed conversion can be realized and TV viewing that is easy to hear is possible.

  In addition, when speech speed conversion is performed with a stereo signal as in the configuration of the prior art, it is necessary to perform mutual time management processing of the L channel and the R channel, and an extra memory is expected. The speech speed conversion processing system has a disadvantage that the sound localization information is lost by reproducing the audio LR signal which is a monaural signal distributed as in the present invention. With the simple configuration, it is possible to realize easy-to-listen speech speed conversion that keeps the time correspondence in the conversation between both channels with a simple configuration. For example, it is difficult to hear early conversations such as elderly people The benefit is great for viewers.

  In particular, in the LR independent speech speed conversion process, the R channel speech speed conversion is performed after detecting that the L channel speech speed conversion has been completed. Therefore, extra synchronization processing time is added, and there is a time lag between the end of the L channel conversation and the start of the R channel conversation. Misalignment with the image due to speech speed conversion will increase.

  However, according to the speech speed converting apparatus of the present invention, the silence processing between the two channels by the speech speed conversion is performed at the same time. For example, as shown in FIG. T3 at the start of the conversation, and there is no time lag. Therefore, the deviation from the image due to the speech speed conversion can be minimized. That is, the speech speed conversion apparatus of the present invention has a special effect in the speech speed conversion of AV equipment with images such as television receivers, VTRs, and DVDs.

  In the present embodiment, the case where the conversion ratio of the speech speed conversion is double has been described. However, the conversion ratio is not limited to this value, and may be set as necessary. In that case, only the timing corresponding to the time t3 shown in FIG.

  Also, the case of two audio stereo signals has been described as an example, but 5.1 audio such as MPEG-2 AAC, Dolby Digital, and multi-channel audio signals are also added to all audio channels as monaural signals. Needless to say, if the speech speed is converted, the speech speed can be converted with a simple circuit configuration and without time lag.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the speech rate conversion apparatus according to the second embodiment of the present invention. In addition, the same code | symbol shall be attached | subjected with respect to the component same as 1st Embodiment, and the part which overlaps description shall be abbreviate | omitted suitably.

  In FIG. 3, reference numeral 1 is an adder for adding the input L-channel and R-channel audio stereo signals, and 2 is the input of the audio signal that has been converted to a monaural signal by the adder 1, and performing predetermined speech speed conversion. The speech speed conversion processing unit 3 is a distributor that performs speech speed conversion processing by the speech speed conversion processing unit 2 and distributes the output signals to the L channel and the R channel, respectively, and outputs them as audio LR signals. The audio LR signal distributed in the above is used as the L channel and R channel earphone outputs, and the speaker is configured to reproduce the input normal L channel and R channel audio stereo signals.

  The operation of the speech speed converting apparatus configured as described above will be described. In the audio reproduction of the television receiver, the audio signal detected as the L-channel and R-channel audio stereo signals is reproduced as it is by a speaker built in the television receiver. On the other hand, this audio stereo signal is added by the adder 1 and converted into a monaural signal, further subjected to predetermined speech speed conversion by the speech speed conversion processing unit 2, and distributed to the audio LR channel by the distributor 3, respectively. The converted and distributed audio LR signal is reproduced at the earphone terminal added to the television receiver. Note that the speech speed conversion operation and the detailed description of each component are the same as those described in the first embodiment, and are omitted here.

  With the above configuration, normal L-channel and R-channel audio stereo signals are played back with a speaker built in the television receiver, so that a viewer who can understand at normal speaking speed listens to the speaker with normal playback speed. Elderly people who cannot keep up with the speed can listen to the sound signal converted from the earphone through the earphone terminal, so that they can watch the TV on the same TV receiver and enjoy the family together. For elderly people, it becomes a monaural signal and the localization information of the sound is impaired, but the merit of ease of hearing by speech speed conversion is greater.

  Also, by outputting a speech rate conversion signal from the earphone terminal, this signal is used for input, and in combination with a sound skip function such as infrared rays, a more comfortable TV viewing environment for the elderly can be established.

  Further, it is desirable that the earphone terminal output is provided with a volume adjusting unit so that the volume can be adjusted independently from the speaker reproduction side. Furthermore, it is possible to provide a pitch adjusting unit that keeps a predetermined speech speed and varies the pitch. In general, elderly people are not only difficult to follow fast speaking speeds, but also have low listening sensitivity and a narrow range of sounds that can be listened to. TV can be viewed with a setting that is easy to hear without affecting the user.

  According to the speech speed conversion method and the speech speed conversion apparatus according to the present invention, speech speed conversion without time deviation can be realized with a simple circuit configuration, and in particular, when an image is projected, the difference between the image and the voice is minimized. Since it can be made small, it is effective for speech speed conversion with images, and is particularly useful for speech speed conversion not only for television but also for AV equipment such as VTR and DVD.

The block block diagram of the speech-speed converter in the 1st Embodiment of this invention Explanation of timing of speech speed conversion of the present invention Block diagram of the speech rate conversion apparatus in the second embodiment of the present invention Block configuration diagram of a speech speed conversion device according to a conventional embodiment Timing diagram of conventional speech speed conversion 1 is a block diagram of a conventional first speech speed conversion apparatus that does not use the present invention. The block block diagram of the 2nd conventional speech rate converter which does not use this invention

Explanation of symbols

1 adder 2 speech speed conversion processing unit 3 distributor

Claims (3)

A speech speed conversion method comprising: adding a plurality of input channel audio signals to convert them to a monaural signal; and converting the monaural signal to a speech speed. An adder for adding the input L-channel and R-channel audio stereo signals; a speech rate conversion processing unit for inputting a speech signal that has been converted to a monaural signal by the adder and performing a predetermined speech rate conversion; and the speech rate A speech rate conversion apparatus comprising a distributor for distributing an output signal of a conversion processing unit to an L channel and an R channel and outputting the signal as an audio LR signal, and reproducing the audio LR signal with a speaker. An adder for adding the input L-channel and R-channel audio stereo signals; a speech rate conversion processing unit for inputting a speech signal that has been converted to a monaural signal by the adder and performing a predetermined speech rate conversion; and the speech rate A distributor that distributes the output signal of the conversion processing unit to the L channel and the R channel and outputs the signal as an audio LR signal, reproduces the audio stereo signal at a speaker, and reproduces the audio LR signal at an earphone terminal; A speech speed conversion device characterized by that.

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