JP2006246244A - Mobile terminal, sound image controlling device, and sound image controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce impairment of sound quality and deterioration of a level in a sound to be reproduced when a pan-pot is set. <P>SOLUTION: A CPU 12 is designed to extract sound source data of an incoming call melody from a ROM 11, and to output to a sound source 13 when an incoming call is detected. The sound source 13 is designed to extract melody data and pan-pot information of an L channel and an R channel from sound source data, and to output to a DSP unit 16. The DSP unit 16 is designed to determine whether the set value X of the pan-pot is zero or not based on the pan-pot information. When the set value X is determined as zero, the DSP unit 16 is designed to output each melody data as it is without performing a sound image localization process. And each of speakers 19L, 19R is designed to perform monaural reproduction of the incoming call melody based on a signal from a speaker amp 18. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a portable terminal, a sound image control apparatus, and a sound image control method that perform localization of a sound image when reproducing sound data.

  A predetermined signal process is performed on sound data (for example, music data) output from a sound source, a sound image is localized, and sound is reproduced in stereo using a plurality of adjacent speakers. For example, Patent Document 1 describes a foldable mobile phone including a plurality of speakers that can reproduce a ringtone as a stereo. Further, for example, Patent Document 2 describes a sound image moving apparatus that can localize a sound image with high accuracy and reproducibility between a plurality of speakers and can always control the movement of the sound image at a uniform speed.

JP 2004-96573 A (paragraphs 0029-0038, FIGS. 1-3) JP-A-8-205296 (paragraphs 0017-0028, FIGS. 1-3)

  In a mobile terminal such as a mobile phone described in Patent Document 1, signal processing is performed on audio data with a stereo effect by setting PAMPOT (panpot), and a ringing melody or the like may be reproduced in stereo. In this case, generally, the mobile terminal performs signal processing on all audio data regardless of the setting value indicated in the panpot information from the sound source. Therefore, when the set value of the panpot is 0 (that is, when the sound image is localized so that the sound source position recognized by the user is in front), the portable terminal performs signal processing even though the stereo effect cannot be obtained. Will do. Therefore, waste of processing performed by the mobile terminal is large. In addition, the sound quality and level of the audio data change due to the filter characteristics of the signal processing unit that performs signal processing, resulting in deterioration in sound quality and a decrease in level when the incoming melody is played.

  Further, if the sound image moving device described in Patent Document 2 is used for a portable terminal, it is possible to reproduce sound by uniformly controlling the movement of a sound image between a plurality of speakers with high accuracy. However, in the audio data in which the panpot is set, when the panpot setting value is 0, it is impossible to prevent deterioration in sound quality and level reduction when reproducing the sound.

  Therefore, an object of the present invention is to provide a portable terminal, a sound image control apparatus, and a sound image control method that can prevent deterioration in sound quality and level of reproduced sound when a pan pot is set.

  The mobile terminal according to the present invention is a mobile terminal (for example, a mobile phone) that performs localization of sound images when audio data is reproduced in stereo, and is included in the audio data to be processed (for example, sound source data stored in the ROM 11). Process execution determining means (for example, realized by the DSP unit 16) for determining whether or not to perform sound image localization processing that is signal processing for localizing the sound image based on the set value of the panpot; Determines that the sound image localization processing is to be performed, based on signal processing means (for example, realized by the DSP unit 16) that performs sound image localization processing on the sound data to be processed, and sound data output by the signal processing means. The sound reproduction means for reproducing the sound (for example, realized by speakers 19L and 19R) is provided.

  In the portable terminal, the process execution determining unit determines whether the panpot setting value included in the audio data to be processed is 0, and the signal processing unit is configured to determine whether the process execution determining unit sets the panpot. If it is determined that the value is 0, the audio data to be processed is output as it is without performing the audio localization process, and if the process execution determining means determines that the set value of the panpot is not 0, the audio data to be processed is converted into a sound image. A localization process may be performed and output.

  Further, the mobile terminal is realized by a voice storage means (for example, realized by the ROM 11) for storing the incoming melody voice data including the setting value of the panpot, and an incoming call detection means (for example, the CPU 12) for detecting whether or not there is an incoming call. And a voice extraction means (for example, realized by the CPU 12) for extracting the voice data of the incoming melody from the voice storage means when the incoming call detection means detects the incoming call, and the voice reproduction means is a signal processing means. The ring melody may be reproduced based on the sound data output by the.

  The portable terminal is a portable terminal that performs sound image localization when the ringing melody is played back in stereo, and performs signal processing to localize the sound image based on a panpot setting value included in the sound data of the ringing melody. If the process execution determining unit determines whether to perform sound image localization processing, and the process execution unit determines to perform sound image localization processing, the left channel data and the right channel data included in the audio data to be processed On the other hand, a signal processing means for performing sound image localization processing, and an audio reproduction means for reproducing an incoming melody by two adjacent speakers based on the left channel data and the right channel data output by the signal processing means. It is desirable to have it.

  The sound image control apparatus according to the present invention is a sound image control apparatus that performs sound image localization when sound data is played back in stereo, and is used to localize a sound image based on a setting value of a panpot included in the sound data to be processed. Process execution determining means for determining whether or not to perform sound image localization processing, and signal processing for performing sound image localization processing on sound data to be processed when the process execution means determines to perform sound image localization processing And sound reproducing means for reproducing sound based on the sound data output from the signal processing means.

  In addition, the sound image control device includes a sound storage unit that stores sound data including a panpot setting value, and the process execution determination unit is based on the panpot setting value included in the sound data stored in the sound storage unit. Further, it may be determined whether to perform the sound image localization process.

  Further, in the sound image control device, the process execution determining means determines whether or not the panpot setting value included in the audio data to be processed is 0, and the signal processing means is that the process execution determining means is the panpot. If it is determined that the set value is 0, the audio data to be processed is output as it is without performing the audio localization process, and if the process execution determining means determines that the panpot set value is not 0, the audio data to be processed is output. A sound image localization process may be performed and output.

  Further, in the sound image control device, the sound reproduction means reproduces the sound in monaural based on the sound data output by the signal processing means when the signal processing means outputs the sound data to be processed without performing the sound localization process. When the signal processing means outputs the sound data to be processed after performing sound image localization processing, the sound may be reproduced in stereo based on the sound data output by the signal processing means.

  The audio control method according to the present invention is a sound image control method for localizing a sound image when audio data is played back in stereo, and for localizing the sound image based on a set value of a panpot included in the audio data to be processed. A process execution determination step for determining whether or not to perform sound image localization processing, which is signal processing of signal processing, and signal processing for performing sound image localization processing on audio data to be processed when it is determined that sound image localization processing is to be performed And a sound reproduction step of reproducing sound based on the sound data output from the signal processing circuit.

  The audio control method includes an audio storage step for storing audio data including a panpot setting value, and the sound image localization process is performed based on the panpot setting value included in the stored audio data in the process execution determination step. It may be determined whether or not to perform.

  Further, the audio control method determines whether or not the panpot setting value included in the audio data to be processed is 0 in the process execution determination step, and the panpot setting value is 0 in the signal processing step. If it is determined that the signal processing circuit outputs the sound data to be processed without performing the sound localization process, and if the panpot setting value is not 0, the signal processing circuit converts the sound data to be processed to sound image localization. Processing may be performed and output.

  Also, in the audio control method, in the audio reproduction step, when the signal processing circuit outputs the audio data to be processed without performing the audio localization process, the audio is monaurally reproduced based on the audio data output by the signal processing circuit. When the signal processing circuit outputs the sound data after performing sound image localization processing, the sound may be reproduced in stereo based on the sound data output by the signal processing circuit.

  According to the present invention, it is determined whether or not to perform the sound image localization process based on the panpot setting value included in the audio data. Therefore, when the stereo effect cannot be obtained, by not performing the sound localization, it is possible to reproduce the sound with a good sound quality while ensuring the sound pressure. Therefore, when the pan pot is set, it is possible to prevent deterioration in sound quality and level of sound to be reproduced.

  Further, according to the present invention, it is determined whether or not the set value of the pan pot is zero. If it is determined that the set value of the pan pot is 0, the audio data is output as it is to perform the audio localization process. Therefore, when the setting value of the pan pot where the stereo effect cannot be obtained is 0, by not performing the sound localization, it is possible to reproduce the sound with good sound quality while ensuring the sound pressure.

  According to the present invention, when the mobile terminal detects an incoming call, the mobile terminal determines whether or not to perform the sound localization process based on the panpot setting value included in the sound data of the ringing melody. Therefore, when a pan pot is set, it is possible to prevent deterioration of the sound quality and level of the incoming melody reproduced by the mobile terminal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of a sound image control apparatus according to the present invention. As shown in FIG. 1, the sound image control apparatus includes a ROM 11, a CPU 12, a sound source 13, a DSP unit 16, a D / A converter 17, a speaker amplifier 18, and speakers 19L and 19R. In this embodiment, as an example, a case where a sound image control device is used in a mobile phone will be described. Note that the sound image control device is not limited to a mobile phone, and may be used for other mobile terminals such as a PHS.

  In this embodiment, the sound image control device performs sound image localization processing, which is signal processing for performing sound image localization, when a mobile phone reproduces sound data such as a ringing melody in stereo, and outputs sound. In general, when a human recognizes speech by two ears, the brain processes and analyzes the sound source and the sound source based on the subtle sound pressure difference and phase difference that occur between one ear and the other. Recognize direction. In the present embodiment, “localizing a sound image” means controlling the direction of a sound source position recognized by a human by signal processing audio data to give a sound pressure difference and a phase difference.

  The ROM 11 stores audio data (music data) in advance. In the present embodiment, the ROM 11 stores sound source data of a ringing melody that is output as a ringtone as voice data. The ROM 11 stores sound source data to which panpot information including a set value X of PAMPOT (panpot) is added in advance. In the present embodiment, “pan pot” is a musical sound parameter indicating the localization of a sound source during stereo output. In the present embodiment, the panpot information is information for setting the left and right localization of the sound source by including the panpot setting value X. In the present embodiment, the sound source data stored in the ROM 11 is added with panpot information including values from “+7” to “−7” as the panpot setting value X.

  In the present embodiment, the mobile phone downloads sound source data from a Web site that distributes the incoming melody, for example, in accordance with the user's instruction operation, and stores it in the ROM 11 in advance.

  The CPU 12 has a function of performing various controls of the mobile phone according to the program. For example, the CPU 12 performs various processes such as a mobile phone outgoing call process and an incoming call process. Further, when detecting an incoming call, the CPU 12 has a function of extracting sound source data of the incoming melody from the ROM 11 and outputting it to the sound source 13.

  The sound source 13 has a function of outputting two lines of melody data to the DSP unit 16 based on the sound source data from the CPU 12. In the present embodiment, the sound source 13 extracts melody data of the left channel (hereinafter referred to as “L channel”) and melody data of the right channel (hereinafter referred to as “R channel”) included in the sound source data, and supplies them to the DSP unit 16. Output. The sound source 13 has a function of extracting panpot information from the sound source data input from the CPU 12 and outputting the panpot information to the DSP unit 16.

  The DSP unit (signal processing unit) 16 has a function of performing signal processing on two systems of melody data from the sound source 13. In the present embodiment, the DSP unit 16 performs signal processing (sound image localization processing) for locating a sound image on L channel and R channel melody data. For example, the DSP unit 16 performs sound image localization processing by controlling the level and phase of each melody data.

  In the present embodiment, for example, the DSP unit 16 shifts the amplitude and phase of the L channel melody data by a predetermined amount with respect to the R channel melody data. Then, the DSP unit 16 synthesizes the R channel melody data with the L channel melody data whose amplitude and phase are shifted, and outputs the synthesized data to the D / A converter 17. For example, the DSP unit 16 shifts the amplitude and phase of the R-channel melody data by a predetermined amount with respect to the L-channel melody data. Then, the DSP unit 16 synthesizes the L-channel melody data and the R-channel melody data whose amplitude and phase are shifted, and outputs them to the D / A converter 17.

  Further, the DSP unit 16 has a function of determining whether or not the set value of the pan pot is 0 based on the pan pot information from the sound source 13. The DSP unit 16 has a function of determining whether or not to perform sound image localization processing based on the determination result of the panpot setting value. In the present embodiment, the DSP unit 16 sets the sound image localization processing on or off based on the determination result of the panpot setting value.

  The D / A converter 17 has a function of converting the data processed by the DSP unit 16 into an analog signal. The speaker amplifier 18 has a function of increasing / decreasing the level of the signal from the D / A converter 17. The speakers 19L and 19R have a function of outputting sound based on a signal from the speaker amplifier 18. In the present embodiment, the mobile phone includes two speakers 19L and 19R that are close to each other as shown in FIG. A speaker (hereinafter referred to as an L speaker) 19L outputs sound based on an L channel signal. A speaker (hereinafter referred to as R speaker) 19R outputs sound based on the R channel signal.

  Next, the operation will be described. FIG. 2 is a flowchart showing an example of a process for outputting a sound by locating a sound image of a ringing melody when an incoming call is received in a mobile phone. When the mobile phone receives the incoming signal from the base station, the CPU 12 detects the incoming call (step S11). Then, the CPU 12 extracts the sound source data of the incoming melody from the ROM 11, and outputs the extracted sound source data to the sound source 13 (step S12).

  The sound source 13 extracts L channel melody data and R channel melody data from the sound source data input from the CPU 12. The sound source 13 extracts panpot information included in the sound source data. Then, the sound source 13 outputs L channel and R channel melody data and panpot information to the DSP unit 16.

  The DSP unit 16 determines whether or not the panpot setting value X is 0 based on the panpot information input from the sound source 13 (step S13).

  If it is determined that the set value is not 0, the DSP unit 16 performs predetermined sound image localization processing on the L channel and R channel melody data (step S14). In this case, the DSP unit 16 controls the level and phase of each melody data in accordance with the panpot setting value X indicated in the panpot information.

  For example, when the set value X of the pan pot is a positive value (that is, 0 <X <+7), the DSP unit 16 processes each melody data so that the output level of the L channel is higher than that of the R channel. . Further, for example, when the set value X of the pan pot is a positive maximum value (that is, X = + 7), the DSP unit 16 processes each melody data so as to output only from the L channel. For example, when the panpot setting value X is a negative value (that is, −7 <X <0), the DSP unit 16 sets each melody data so that the output level of the R channel is higher than that of the L channel. Process. For example, when the panpot setting value X is a negative maximum value (that is, X = −7), the DSP unit 16 processes each melody data so as to output only from the R channel.

  When the DSP unit 16 processes each melody data, it outputs each processed melody data to the D / A converter 17. Then, the D / A converter 17 converts each melody data into an analog signal and outputs it to the speaker amplifier 18. The speaker amplifier 18 adjusts the level of each signal input from the D / A converter 17 and outputs it to the speakers 19L and 19R. Then, each of the speakers 19L and 19R rings based on the L channel and R channel signals, and outputs the sound of the incoming melody (step S15).

  If it is determined in step S13 that the set value X is 0, the DSP unit 16 determines that signal processing of each melody data is not performed. The DSP unit 16 outputs the melody data to the D / A converter 17 as it is without performing signal processing. Then, the D / A converter 17 converts each melody data into an analog signal, the speaker amplifier 18 adjusts the level, and the speakers 19L and 19R output sound. That is, the sound image control apparatus reproduces the sound of the incoming melody in monaural based on the same signal from the L channel and the R channel without performing the sound localization process.

  Next, the concept of sound image localization performed according to the process shown in FIG. 2 will be described. FIG. 3 is an explanatory diagram showing the concept of sound image localization based on the set value of the pan pot. In the present embodiment, any value from “−7” to “+7” is set as the set value of the pan pot. When the set value of the pan pot is “+7”, the mobile phone outputs sound from only the L channel based on the melody data. In this case, as shown in FIG. 3A, the DSP unit 16 performs signal processing for localizing the L channel melody data to the left side, so that the mobile phone outputs sound only from the L channel. Therefore, when viewed from the viewer, the sound image is localized on the left side and the incoming melody can be heard as if the virtual sound source is in the 45 ° direction on the left side.

  When the set value of the pan pot is “−7”, the mobile phone outputs sound only from the R channel based on the melody data. In this case, as shown in FIG. 3C, the DSP unit 16 performs signal processing for localizing the R channel melody data to the right side, so that the mobile phone outputs sound only from the R channel. Therefore, when viewed from the viewer, the sound image is localized on the right side and the incoming melody can be heard as if the virtual sound source is in the 45 degree direction on the right side.

  When the set value of the pan pot is 0, the mobile phone outputs audio from the L channel and the R channel based on the same monaural signal, as shown in FIG. Since it is monaural reproduction, when viewed from the viewer, the incoming melody can be heard as if the sound source is in the front direction with respect to the viewer.

  As shown in FIG. 3, by setting a panpot value in advance to the sound source data of the incoming melody, the sound image can be localized to the left or right even when using a close speaker, and the stereo effect can be achieved. Obtainable.

  Next, the operation in which the mobile phone performs signal processing according to the processing shown in FIG. 2 will be specifically described. FIG. 4 is an explanatory diagram showing an operation when sound image localization processing is performed using two adjacent speakers in the mobile phone. As shown in FIG. 4, the DSP unit 16 includes four signal processing circuits 16A, 16B, 16C, and 16D. In FIG. 4, for convenience of explanation, the ROM 11, CPU 12, D / A converter 17, and speaker amplifier 18 are omitted, but the DSP unit 16 actually has the D / A converter 17 and speaker amplifier 18. Are connected to the speakers 19L and 19R.

  In the present embodiment, the signal processing circuit 16A performs signal processing on the R channel melody data input from the sound source 13 and outputs it to the R speaker 19R side. Further, the signal processing circuit 16B performs signal processing on the L channel melody data input from the sound source 13 and outputs it to the R speaker 19R side. Further, the signal processing circuit 16C performs signal processing on the R channel melody data input from the sound source 13 and outputs it to the L speaker 19L side. Further, the signal processing circuit 16D performs signal processing on the L channel melody data input from the sound source 13 and outputs it to the L speaker 19L side.

  First, a case where sound image localization processing is performed on the L channel melody data from the melody sound source 13 using two adjacent speakers 19L and 19R will be described. The signal processing circuit 16D performs signal processing on the L channel melody data from the sound source 13 by controlling the level and phase, and outputs the processed signal to the L speaker 19L side. Then, the L speaker 19L rings and outputs sound based on the processed signal. Similarly, the signal processing circuit 16B performs signal processing on the L channel melody data from the sound source 13 by controlling the level and phase, and outputs the processed signal to the R speaker 19R side. Then, the R speaker 19R rings and outputs a sound based on the processed signal.

  The sound output from the L speaker 19L is transmitted to the viewer's left ear 22 via the path 27. Also, the sound output from the L speaker 19L is transmitted to the viewer's right ear 21 via the path 26. Similarly, the sound output from the R speaker 19 </ b> R is transmitted to the left ear 22 via the path 28 and is transmitted to the right ear 21 via the path 25. Therefore, the viewer listens to the sound transmitted from the L speaker 19L via the path 27 and the sound transmitted from the R speaker 19R via the path 28 with the left ear 22. Similarly, the viewer listens to the sound transmitted from the L speaker 19L via the path 26 and the sound transmitted from the R speaker 19R via the path 25 with the right ear 21.

  For example, when the set value of the pan pot is “+7”, the signal processing circuit 16B and the signal processing circuit 16D are connected to the binaural 21 from the L speaker 19L and the R speaker 19R in order to localize the sound image in the direction of 45 degrees to the left. In consideration of the transmission characteristics of the sound transmitted to 22, signal processing is performed so that a predetermined sound pressure difference and a predetermined time difference occur in both ears 21 and 22. In this case, since the sound from the L speaker 19L and the sound from the R speaker 19R interfere with each other in space and the sound is localized, the signal processing circuit 16B and the signal processing circuit 16D are close to each other in opposite phase. The melody data is signal-processed so as to be in phase and output to the speakers 19L and 19R. Thus, by processing the level and phase so that a sound pressure difference and a time difference are generated in both ears 21 and 22, the viewer feels that the sound can be heard from both ears 21 and 22 from the left direction of 45 degrees. be able to.

  Similarly, when the set value of the pan pot is “−7”, the signal processing circuit 16A and the signal processing circuit 16C are connected to the L speaker 19L and the R speaker 19R in order to localize the sound image in the 45 ° right direction. In consideration of the transmission characteristics of the sound transmitted to both ears 21 and 22, signal processing is performed so that a predetermined sound pressure difference and a predetermined time difference are generated in both ears 21 and 22. The sound image is localized to the right side by causing the sound output from the L speaker 19L and the sound output from the R speaker 19R to interfere with each other in space.

  When the set value of the pan pot is 0, the DSP unit 16 outputs each melody data as it is without performing the sound image localization process. In the present embodiment, the DSP unit 16 sets the sound image localization processing on or off based on the setting value of the pan pot in order to prevent a change in sound quality or sound pressure. In the present embodiment, the DSP unit 16 inputs panpot information from the sound source 13 in addition to the L channel and R channel melody data. The DSP unit 16 performs sound image localization processing based on the melody data and panpot information of each channel.

  For example, the DSP unit 16 determines whether or not the set value of the pan pot included in the pan pot information is zero. If it is determined that the set value is 0, the DSP unit 16 sets the sound image localization processing to OFF, and outputs each melody data to the speakers 19L and 19R as it is without performing signal processing. If it is determined that the set value is not 0, the DSP unit 16 sets the sound image localization processing to ON, performs signal processing on each melody data, and outputs it to the speakers 19L and 19R.

  FIG. 5 is an explanatory diagram illustrating an example in which the DSP unit 16 sets the sound image localization process to ON or OFF. FIG. 5A shows an example of each melody data input from the sound source 13 by the DSP unit 16. FIG. 5B shows an example of panpot setting values included in the panpot information input from the sound source 13 by the DSP unit 16. FIG. 5C shows an example of a setting state in which the sound image localization processing by the DSP unit 16 is turned on or off.

  In the example shown in FIG. 5, for example, in the section t <b> 1, the panpot setting value is 0, so that the DSP unit 16 sets the sound image localization processing to OFF as shown in FIG. 5C. That is, since the effect of sound image localization cannot be obtained, the DSP unit 16 outputs the sound as it is to the speakers 19L and 19R without performing sound image localization processing in order to prevent changes in sound quality and sound pressure of the output sound. Further, for example, in the section t2, since the set value of the pan pot is “+7”, the DSP unit 16 sets the sound image localization process to ON as shown in FIG. 5C. That is, the DSP unit 16 processes each melody data to localize the sound image to the left side. Further, for example, in the section t3, since the panpot setting value is “−7”, the DSP unit 16 sets the sound image localization processing to ON as shown in FIG. 5C. That is, the DSP unit 16 processes each melody data to localize the sound image to the right side.

  Similarly, in the section t4, since the panpot setting value is “+7”, the DSP unit 16 performs signal processing on the melody data to localize the sound image to the left side. In section t5, since the panpot setting value is 0, the DSP unit 16 outputs monaural without performing signal processing. In section t6, since the panpot setting value is “−7”, the DSP unit 16 processes the melody data to localize the sound image to the right side.

  By executing the processing described above, the DSP unit 16 performs signal processing based on the panpot information of the sound source data so that a stereo effect by sound image localization can be obtained when the panpot setting value is not zero. To localize the sound image to the left or right. When the panpot setting value is 0, the sound image is not localized even if signal processing is performed, so the DSP unit 16 outputs each melody data as it is without performing signal processing.

  For example, in general, when a mobile phone localizes an incoming melody or the like and outputs a sound, the mobile phone performs signal processing of each melody data even if the panpot setting value is zero. In this case, the signal processing circuit 16D performs level and phase control on the L channel melody data and outputs the result to the L speaker 19L side. Further, the signal processing circuit 16C performs level and phase control on the R channel melody data and outputs the result to the L speaker 19L side. The L speaker 19L then synthesizes the signal from the signal processing circuit 16D side and the signal from the signal processing circuit 16C side, and sounds and outputs sound based on the synthesized signal.

  Similarly, the signal processing circuit 16A performs level and phase control on the R channel melody data and outputs the result to the R speaker 19R side. Further, the signal processing circuit 16B performs level and phase control on the L channel melody data and outputs the result to the R speaker 19R side. The R speaker 19R synthesizes the signal from the signal processing circuit 16A side and the signal from the signal processing circuit 16B side, and sounds and outputs sound based on the synthesized signal.

  When signal processing is performed and the sound is output when the set value of the panpot is 0, for example, the L speaker 19L converts the L channel signal from the signal processing circuit 16D side and the signal processing circuit 16C into the L channel signal. On the other hand, an R channel signal that has undergone signal processing so as to have an opposite phase is synthesized and sounded and output as a voice. Therefore, since the L channel signal and the R channel signal are the same and have a phase close to the opposite phase, the signal level is lowered by the synthesis. Similarly, the R speaker 19R also synthesizes signals that are close to opposite phases, so that the signal level is lowered. For this reason, if the panpot setting value is 0 and the signal processing is performed even though the sound image localization effect cannot be obtained, the sound quality and volume of the output sound will change.

  In the present embodiment, when the set value of the pan pot is 0 based on the pan pot information included in the sound source data, monaural sound is output from the left and right speakers 19L and 19R without performing signal processing. Therefore, even when the pan pot is 0, the sound quality and volume of the sound output from the speakers 19L and 19R can be ensured.

  As described above, according to the present embodiment, the DSP unit 16 determines whether or not the panpot setting value X included in the panpot information is zero. If the DSP unit 16 determines that the panpot setting value X is 0, the DSP unit 16 outputs the melody data of the L channel and the R channel as it is without performing the sound image localization process. The speakers 19L and 19R ring on the basis of the L channel and R channel signals, respectively, and reproduce the incoming melody in monaural. According to the present embodiment, when the setting value X of the pan pot where the stereo effect cannot be obtained is 0, the sound is not localized, so that the ringing melody can be played with good sound quality while ensuring the sound pressure. Can be played. Therefore, when the pan pot is set, it is possible to prevent deterioration of the sound quality and level of the incoming melody to be reproduced.

  In the present embodiment, the case where the mobile phone reproduces and outputs the incoming melody has been described. However, the sound reproduced by the sound image control device performing the sound image localization process is not limited to the incoming melody. For example, the sound image control device can also be applied to the case where the mobile phone outputs other sounds such as game sound effects from a speaker and reproduces and outputs sound such as game sound effects.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a use of a mobile phone having a plurality of adjacent speakers for stereo reproduction of an incoming melody when a call is received. Further, the present invention can be applied to the use of stereo reproduction of game sound effects in a mobile phone.

It is a block diagram which shows an example of a structure of the sound image control apparatus by this invention. 10 is a flowchart illustrating an example of a process of outputting a sound by localizing a sound image of a ringing melody when an incoming call is received in a mobile phone. It is explanatory drawing which shows the concept of the sound image localization based on the setting value of a panpot. It is explanatory drawing which shows operation | movement in the case of performing a sound image localization process using two adjacent speakers in a mobile telephone. It is explanatory drawing which shows the example in case the DSP part 16 sets ON or OFF of a sound image localization process.

Explanation of symbols

11 ROM
12 CPU
13 Sound source 16 DSP section 16A, 16B, 16C, 16D Signal processing circuit 17 D / A converter 18 Speaker amplifier 19L, 19R Speaker

Claims (12)

A portable terminal that performs localization of sound images when audio data is played back in stereo,
A process execution determining means for determining whether or not to perform sound image localization processing, which is signal processing for localizing a sound image, based on a setting value of a panpot included in audio data to be processed;
When it is determined that the processing execution means performs sound image localization processing, signal processing means for performing the sound image localization processing on the audio data to be processed;
A portable terminal comprising: audio reproduction means for reproducing audio based on the audio data output by the signal processing means. The process execution determining means determines whether the set value of the panpot included in the audio data to be processed is 0,
The signal processing means
When the process execution determining means determines that the panpot setting value is 0, the audio data to be processed is output as it is without performing the audio localization process,
The portable terminal according to claim 1, wherein when the processing execution determining unit determines that the setting value of the pan pot is not 0, the audio data to be processed is output by performing a sound image localization process. Voice storage means for storing the incoming melody voice data including the setting value of the panpot;
An incoming call detection means for detecting whether there is an incoming call;
A voice extraction means for extracting voice data of the incoming melody from the voice storage means when the incoming call detection means detects an incoming call;
The portable terminal according to claim 1 or 2, wherein the voice reproduction means reproduces the incoming melody based on the voice data output by the signal processing means. A mobile device that performs localization of sound images when playing ringtones in stereo,
A process execution determining means for determining whether or not to perform sound image localization processing, which is signal processing for localizing a sound image, based on a setting value of a panpot included in the sound data of the ringing melody;
When it is determined that the processing execution means performs sound image localization processing, signal processing means for performing the sound image localization processing on left channel data and right channel data included in the audio data to be processed,
A portable terminal comprising: voice reproduction means for reproducing a ringing melody by two adjacent speakers based on the left channel data and right channel data output by the signal processing means. A sound image control device that performs localization of sound images when audio data is reproduced in stereo,
A process execution determining means for determining whether or not to perform sound image localization processing, which is signal processing for localizing a sound image, based on a setting value of a panpot included in audio data to be processed;
When it is determined that the processing execution means performs sound image localization processing, signal processing means for performing the sound image localization processing on the audio data to be processed;
An audio image control apparatus comprising: audio reproduction means for reproducing audio based on the audio data output by the signal processing means. Audio storage means for storing audio data including panpot setting values;
The sound image control apparatus according to claim 5, wherein the process execution determination unit determines whether or not to perform the sound image localization process based on a panpot setting value included in the sound data stored in the sound storage unit. The process execution determining means determines whether the set value of the panpot included in the audio data to be processed is 0,
The signal processing means
When the process execution determining means determines that the panpot setting value is 0, the audio data to be processed is output as it is without performing the audio localization process,
7. The sound image control device according to claim 5, wherein, when the processing execution determination unit determines that the setting value of the pan pot is not 0, the sound data to be processed is subjected to sound image localization processing and output. 7. Audio playback means
When the signal processing means outputs the sound data to be processed without performing the sound localization process, the sound is monaurally reproduced based on the sound data output by the signal processing means,
The sound image control device according to claim 7, wherein when the signal processing means performs sound image localization processing on the sound data to be processed and outputs the sound data, the sound is reproduced in stereo based on the sound data output by the signal processing means. A sound image control method for localizing a sound image when audio data is played back in stereo,
A process execution determination step for determining whether or not to perform sound image localization processing, which is signal processing for localizing a sound image, based on a setting value of a panpot included in audio data to be processed;
When it is determined that the sound image localization processing is performed, a signal processing step in which a signal processing circuit performs sound image localization processing on the audio data to be processed;
And a sound reproduction step of reproducing sound based on the sound data output from the signal processing circuit. Including a voice storage step of storing voice data including a set value of the panpot;
The sound image control method according to claim 9, wherein in the process execution determination step, it is determined whether or not to perform sound image localization processing based on a panpot setting value included in the stored audio data. In the process execution determining step, it is determined whether or not the panpot setting value included in the audio data to be processed is 0,
In the signal processing step,
If it is determined that the set value of the pan pot is 0, the signal processing circuit outputs the audio data to be processed as it is without performing the audio localization process,
The sound image control method according to claim 9 or 10, wherein when the set value of the pan pot is determined to be not 0, the signal processing circuit performs sound image localization processing on the sound data to be processed and outputs the sound data. In the audio playback step,
When the signal processing circuit outputs the sound data to be processed without performing the sound localization process, the sound is monaurally reproduced based on the sound data output by the signal processing circuit,
The sound image control method according to claim 11, wherein when the signal processing circuit performs sound image localization processing on the sound data and outputs the sound data, the sound is reproduced in stereo on the basis of the sound data output from the signal processing circuit.

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