JP2010016483

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DESCRIPTION JP2010016483
[PROBLEMS] To realize correction of music data according to an individual's hearing
characteristic by a simple process. A measuring unit measures a frequency characteristic of a
user's hearing formed at a plurality of frequency points. The level shift unit 18 shifts the
frequency characteristic value of the hearing ability by a fixed amount in a predetermined band
so that the measured frequency characteristic value of the hearing ability approaches the ideal
frequency characteristic value at at least one frequency point in the ideal frequency
characteristic. Do. The derivation unit 20 derives, at each frequency point, the difference value
between the frequency characteristic value of the level shifted auditory sense and the ideal
frequency characteristic value, and then weights the difference value at each frequency point by
the weighting factor for each frequency point. Derive the correction factor for each frequency
point. The filter unit 22 corrects the audio signal based on the correction coefficient and the level
shift amount when level shifting the frequency characteristic value of the hearing. [Selected
figure] Figure 1
Audio signal correction device
[0001]
The present invention relates to audio signal correction technology, and more particularly to an
audio signal correction device that corrects an audio signal in accordance with the user's hearing
ability.
[0002]
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1
Conventionally, in stereo or surround devices, sound field corrections such as gain, frequency
characteristics, etc. are made uniform or at the viewer's preference.
In addition, it takes time and effort to execute the correction, and the procedure is complicated
(see, for example, Patent Document 1). Unexamined-Japanese-Patent No. 2002-281599
[0003]
In recent years, portable digital audio players (hereinafter referred to as reproduction
devices ) have become widespread, and reproduction devices reproduce data compressed by
MP3 or the like. In such a reproduction apparatus, it may be difficult to hear the reproduced
music data due to the background noise of the room or the surrounding environment. Also, the
way of hearing varies depending on individual differences such as the age of the user. Therefore,
also in the playback apparatus, a function for correcting audio data is required. On the other
hand, in the playback apparatus, since the number of buttons and the like is small, improvement
in operability for the user is required. In addition, in consideration of the processing capability of
the playback apparatus, simplification of processing when performing correction is required.
[0004]
The present invention has been made in view of such a situation, and an object thereof is to
provide a technique for realizing correction of music data according to an individual's hearing
ability by a simple process.
[0005]
In order to solve the above problems, an audio signal correction apparatus according to an
aspect of the present invention includes a measurement unit that measures frequency
characteristics of the user's hearing formed at a plurality of frequency points over a
predetermined band, and a measurement Hearing power so that the measured frequency
characteristic value of the hearing ability approaches the ideal frequency characteristic value at
at least one frequency point in the ideal frequency characteristic preset as the characteristic of
the ideal hearing ability with respect to the frequency characteristic of the hearing ability After
deriving the difference value between the frequency characteristic value of the hearing ability
level-shifted in the level shift unit and the level shift unit that shifts the frequency characteristic
value by a fixed amount in a predetermined band at each frequency point, By weighting the
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difference value at each frequency point by the weighting factor for each frequency point A
derivation unit for deriving a correction coefficient for each frequency point, a correction
coefficient for each frequency point derived at the derivation unit, and a level shift amount at the
time of level shifting the frequency characteristic value of the hearing at the level shift unit. And
a correction unit that corrects the audio signal.
The measurement unit measures the frequency characteristic of the hearing in the sound
pressure region whose level is larger than the ideal frequency characteristic value, and the
weighting factor for each frequency point in the derivation unit is specified to increase as the
frequency increases. .
[0006]
According to this aspect, in the case of deriving the amplification factor based on the difference
between the ideal level and the measured hearing level, the hearing level is measured in a region
that is worse than the ideal level, so that the measured hearing level is attenuated. Motion can be
omitted, and correction of music data according to the individual's hearing characteristics can be
realized by a simple operation.
[0007]
Another aspect of the present invention is also an audio signal correction device.
This device has a measuring unit for measuring the frequency characteristic of the user's hearing
formed at a plurality of frequency points over a predetermined band, and an auditory
characteristic ideal for the frequency characteristic of the hearing measured at the measuring
unit. Level shift by shifting the frequency characteristic value of the hearing ability by a
predetermined amount in a predetermined band so that the measured frequency characteristic
value of the hearing ability approaches the ideal frequency characteristic value at at least one
frequency point in the set ideal frequency characteristics The difference value between the
frequency characteristic value of the hearing aid whose level has been shifted in the level shift
unit and the ideal frequency characteristic value is derived at each frequency point, and the
difference value at each frequency point is weighted by the weighting factor for each frequency
point To derive a correction coefficient for each frequency point by A correction coefficient for
each frequency point derived in the derivation unit, based on the level shift amount when shifting
a level of the frequency characteristic values of the hearing in the level shift unit, and a
correcting unit for correcting the audio signal. The derivation unit stores a plurality of types of
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weighting coefficients, and the correction unit selects one of the plurality of types of weighting
coefficients based on the type of the audio signal to be corrected.
[0008]
According to this aspect, a plurality of types of weighting factors to be used when generating the
correction factor are stored, and one weighting factor is selected according to the type of audio
signal to be corrected, so that it is suitable for the type of audio signal A correction factor can be
generated.
[0009]
Another aspect of the present invention is also an audio signal correction device.
This device has a measuring unit for measuring the frequency characteristic of the user's hearing
formed at a plurality of frequency points over a predetermined band, and an auditory
characteristic ideal for the frequency characteristic of the hearing measured at the measuring
unit. Level shift by shifting the frequency characteristic value of the hearing ability by a
predetermined amount in a predetermined band so that the measured frequency characteristic
value of the hearing ability approaches the ideal frequency characteristic value at at least one
frequency point in the set ideal frequency characteristics The difference value between the
frequency characteristic value of the hearing aid whose level has been shifted in the level shift
unit and the ideal frequency characteristic value is derived at each frequency point, and the
difference value at each frequency point is weighted by the weighting factor for each frequency
point To derive a correction coefficient for each frequency point by A correction coefficient for
each frequency point derived in the derivation unit, based on the level shift amount when shifting
a level of the frequency characteristic values of the hearing in the level shift unit, and a
correcting unit for correcting the audio signal. The deriving unit derives a weighting factor for
each frequency point based on the audio signal to be corrected in the correcting unit.
[0010]
According to this aspect, the weighting factor is generated based on the audio signal to be
corrected, and the correction factor is derived based on the generated weighting factor, so that
the correction factor suitable for the audio signal can be generated.
[0011]
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Note that arbitrary combinations of the above-described components, and conversions of the
expression of the present invention among methods, apparatuses, systems, recording media,
computer programs and the like are also effective as aspects of the present invention.
[0012]
According to the present invention, it is possible to realize correction of music data according to
an individual's hearing ability by a simple process.
[0013]
Example 1 Before specifically describing the present invention, an outline will first be described.
The first embodiment of the present invention relates to a reproducing apparatus for
reproducing music data as the above-mentioned portable player.
Here, the playback device does not play back the stored music data as it is, but plays back after
correcting it according to the user's preference.
It is desirable that the operation for correcting the music data be simple in consideration of the
environment where the operability is limited, such as a portable player, and the processing
capability. In order to cope with this, the reproducing apparatus according to the first
embodiment executes the following process. The playback device corrects the music data with a
filter such as an equalizer, but inspects the user's hearing characteristics prior to the correction,
and determines the filter coefficients according to the inspection result (hereinafter referred to as
inspection process ).
[0014]
In such an inspection process, the reproduction apparatus reproduces tone signals corresponding
to each of a plurality of frequency values (hereinafter referred to as "frequency points") in order.
At this time, the playback device plays each tone signal so that the volume increases with the
passage of time. The user depresses a button provided on the playback apparatus at the timing at
which the reproduced tone signal is heard. By repeating such processing for a plurality of tone
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signals, the reproduction device acquires frequency characteristics of hearing levels over a
plurality of frequency points (hereinafter referred to as hearing characteristics data ). In
addition, the reproduction device stores in advance the frequency characteristics (hereinafter
referred to as ideal characteristic data ) of the ideal hearing level (hereinafter referred to as
ideal level ) as the characteristics of ideal hearing with respect to the hearing characteristic
data.
[0015]
The playback apparatus generally shifts the level of the hearing characteristic data in the
attenuation direction so that the hearing characteristic data and the ideal characteristic data
approach at at least one frequency point (the value at that time is referred to as "level shift
amount". ). Furthermore, the reproduction apparatus determines a difference value at each
frequency point for the level-shifted hearing characteristic data and the ideal characteristic data.
Also, the playback apparatus stores weighting factors for each frequency point based on the
frequency characteristics of music data, and derives a correction value for each frequency point
using the weighting factors and the difference value. Finally, the reproduction apparatus sets the
correction value to the filter and sets the level shift amount to the amplifier.
[0016]
Here, the examination is performed so that the hearing characteristic data is acquired in a sound
pressure area having a level higher than that of the ideal characteristic data. Specifically, even if
the user can hear when the tone signal is at the lowest volume, the hearing level is higher than
the ideal level. As a result, the level shift amount becomes a positive value, that is, a value that
attenuates at the time of level shift, becomes a value that is amplified when setting to the
amplifier, and other combinations are excluded. It becomes easy. Also, for the user, the operation
is simplified because the user only depresses the button at the timing when the tone signal is
heard.
[0017]
FIG. 1 shows the configuration of a playback apparatus 100 according to a first embodiment of
the present invention. The reproduction apparatus 100 includes a reception unit 10, a control
unit 12, a storage unit 14, an inspection unit 32, a filter unit 22, a reproduction unit 24, a SW
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unit 26, a DAC unit 28, an output unit 30, and a display unit 34. The inspection unit 32 includes
a measurement unit 16, a level shift unit 18, and a derivation unit 20, and the storage unit 14
includes inspection data 50, music data 52, ideal characteristic data 54, and a weighting factor
56.
[0018]
The receiving unit 10 receives an instruction from the user, and outputs the received instruction
to the control unit 12. For example, the receiving unit 10 is configured to include a button, and
receives various instructions from the user by detecting that the button is pressed by the user.
The various instructions are, for example, (1) an instruction to start the examination process, (2)
a notification that the tone signal has been heard in the examination process, and (3) an
instruction to select music data to be reproduced and reproduce the selected music data. is there.
The control unit 12 controls the overall operation of the playback device 100. When the control
unit 12 receives an instruction from the reception unit 10, the control unit 12 instructs the
operation of the SW unit 26, the measurement unit 16, and the reproduction unit 24 according
to the content of the instruction. The contents of the specific instructions will be described in the
respective components. In addition, the control unit 12 controls the display on the display unit
34 according to the content of the received instruction. Hereinafter, after the operation of the
inspection process is described, the operation of the process of reproducing music data
(hereinafter, referred to as reproduction process ) will be described.
[0019]
The measurement unit 16 inputs an instruction to start the inspection process from the control
unit 12. When the measurement unit 16 receives an instruction to start the inspection process,
the measurement unit 16 starts the inspection process. That is, the measurement unit 16
measures the frequency characteristic of the user's hearing level formed at a plurality of
frequency points and the above-mentioned hearing characteristic data. The storage unit 14
stores a plurality of types of digitized data. Specifically, test data 50, music data 52, ideal
characteristic data 54, and weighting factors 56 are stored. The description of these data will be
described along with the process in which the data is used. The inspection data 50 is formed by a
plurality of tone signals, and each tone signal corresponds to each of a plurality of frequency
points. Here, eight tone signals corresponding to each of eight frequency points correspond to
inspection data 50.
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[0020]
The measurement unit 16 acquires the inspection data 50 from the storage unit 14. The
measuring unit 16 selects one of the plurality of tone signals, for example, the tone signal of the
lowest frequency. The measurement unit 16 reproduces the selected tone signal. At that time,
playback is performed so that the volume gradually increases. The measuring unit 16 outputs the
reproduced tone signal to the SW unit 26. The SW unit 26 connects the measuring unit 16 and
the DAC unit 28 when an instruction of the inspection process is input from the control unit 12.
That is, the SW unit 26 outputs the tone signal input from the measurement unit 16 to the DAC
unit 28. The DAC unit 28 receives a digital signal, converts the digital signal into an analog
signal, and outputs the analog signal to the output unit 30. In the inspection process, the DAC
unit 28 inputs a tone signal as a digital signal, and outputs a tone signal as an analog signal
(hereinafter also referred to as a tone signal ) to the output unit 30.
[0021]
The output unit 30 is formed of a headphone and a speaker, and receives and outputs an analog
signal from the DAC unit 28. In the inspection process, the output unit 30 outputs a tone signal.
The display unit 34 is formed by a display or the like and displays various types of information.
The display unit 34 inputs data on the display content from the control unit 12. Here, the display
contents in the inspection process will be described. FIG. 2 shows a screen displayed on the
display unit 34. A playback level bar 120 is displayed in the center of the screen. The left side of
the reproduction level bar 120 corresponds to a state in which the volume of the tone signal
output from the output unit 30 is small, and the right side of the reproduction level bar 120
corresponds to a state in which the volume of the tone signal output from the output unit 30 is
large. Do.
[0022]
The current level pointer 122 corresponds to the current volume. As described above, since the
volume of the tone signal output from the output unit 30 gradually increases, the current level
pointer 122 is displayed as moving from the left side to the right side of the reproduction level
bar 120. The decision button 124 and the cancel button 126 are buttons for instructing
"decision" and "cancel". Specifically, when the user listening to the tone signal output from the
output unit 30 hears the tone signal, the user aligns the cursor with the determination button
124 and depresses the button of the receiving unit 10. As a result, the control unit 12 recognizes
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that the user can hear the tone signal. Return to FIG. The control unit 12 notifies the measuring
unit 16 of the recognized timing (hereinafter referred to as recognition timing ).
[0023]
The measurement unit 16 receives the recognition timing from the control unit 12. The
measuring unit 16 also stores the relationship between the volume and the timing when
reproducing the tone signal, and specifies the volume corresponding to the recognition timing
based on the recognition timing from the control unit 12. The specified volume corresponds to
the hearing level for one tone signal. This corresponds to the hearing level for one frequency
point. When the hearing level is acquired, the measuring unit 16 changes the frequency point
and executes the same processing. Finally, the measurement unit 16 acquires hearing
characteristic data.
[0024]
FIG. 3 shows the measurement result in the measurement unit 16. The horizontal axis
corresponds to the frequency, and the vertical axis corresponds to the volume level output from
the output unit 30. Each frequency point is shown as "f1" to "f8". Also, the hearing levels for each
frequency point are shown as "A1" to "A8". The hearing characteristic data corresponds to a
combination of A1 to A8 but may be a line connecting A1 to A8 . The audible
area 200 is a part where the volume level is larger than the hearing characteristic data, and the
inaudible area 202 is a part where the volume level is smaller than the hearing characteristic
data. In the audible area 200, the user can hear the tone signal, and in the inaudible area 202,
the user can not hear the tone signal. Return to FIG.
[0025]
The ideal characteristic data 54 stored in the storage unit 14 is as shown in FIG. 4 corresponding
to FIG. 3. FIG. 4 shows the ideal characteristic data 54 stored in the storage unit 14. The
horizontal and vertical axes of FIG. 4 are shown in the same manner as FIG. The ideal levels for
each frequency point are shown as "B1" to "B8". The ideal characteristic data 54 corresponds to a
combination of B1 to B8 , but may be a line connecting B1 to B8 . The ideal
characteristic data 54 can be said to be a minimum audible curve based on a frequency
characteristic which is preset as an ideal minimum audio frequency characteristic in hearing.
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[0026]
The level shift unit 18 receives the hearing characteristic data from the measurement unit 16
and also receives the ideal characteristic data 54 from the storage unit 14. The level shift unit 18
identifies at least one frequency point, for example, the frequency point with the smallest
difference between the hearing level and the ideal level, by comparing the hearing characteristic
data with the ideal characteristic data 54. The level shift unit 18 shifts the level of the hearing
characteristic data in the attenuation direction in the entire band so that the hearing level
matches the ideal level at the specified frequency point. The shift amount at this time
corresponds to the level shift amount , and the above processing corresponds to attenuating
the hearing characteristic data by the level shift amount .
[0027]
5A to 5B show an outline of processing in the level shift unit 18. FIG. 5A is a state before level
shift in the level shift unit 18, and corresponds to a state in which FIG. 3 and FIG. 4 are
superimposed. FIG. 5 (b) corresponds to a state in which the hearing characteristic data is
amplified. Also, hearing levels A1 to A8 are shown as A1 ′ to A8 ′ . Return to
FIG. Here, the volume level in the ideal characteristic data 54 of FIG. 4 is smaller than the volume
level in the hearing characteristic data of FIG. 3. That is, attenuation is performed by the level
shift amount in the level shift unit 18, and amplification is not performed. This corresponds to
the fact that the hearing characteristic data is measured in the region where the volume level is
larger than the ideal characteristic data 54 in the measuring unit 16. Specifically, even if the user
depresses the button when the volume level from the output unit 30 is the smallest and the
control unit 12 recognizes the audible timing, the hearing level is higher than the ideal level in
FIG. 5A. The tone signal is reproduced so that it is also high. The level-shifted hearing
characteristic data is also referred to as "hearing characteristic data" below.
[0028]
The derivation unit 20 derives the difference value between the hearing characteristic data and
the ideal characteristic data 54 at each frequency point. That is, the difference value between the
hearing level "Ai '(i = 1 to 8)" and the ideal level "Bi (i = 1 to 8)" at each frequency point is
calculated. The weighting factors 56 of the storage unit 14 are determined to correspond to each
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of the frequency points. Hereinafter, a plurality of weighting factors 56 over a plurality of
frequency points and one weighting factor 56 will be referred to as weighting factors 56
without distinction. The derivation unit 20 receives the weighting factor 56 from the storage unit
14. The derivation unit 20 derives a correction value by multiplying the difference value by the
weighting factor 56 while associating frequency points. This corresponds to deriving a correction
value for each frequency point by weighting the difference value at each frequency point with
the weighting factor 56 for each frequency point. Hereinafter, a plurality of correction values
over a plurality of frequency points and one correction value are referred to as correction
values without distinction.
[0029]
FIG. 6 shows an outline of processing in the derivation unit 20. FIG. 6 is shown similarly to FIG.
The difference values "D1" to "D8" are derived at each frequency point. Also shown is music
waveform 204. The music waveform 204 is a frequency characteristic for predetermined music
data. Generally, the frequency characteristics of music data differ depending on the type of music
data, so the music waveform 204 corresponds to the frequency characteristics obtained by
averaging the frequency characteristics of a plurality of types of music data. Also, the reciprocal
of the value corresponding to each frequency point of the music waveform 204 corresponds to
the above-mentioned weighting factor 56. When the weighting factor 56 is indicated as "E1" to
"E8", values corresponding to each frequency point of the music waveform 204 are indicated as
"1 / E1" to "1 / E8". Thus, the weighting factor 56 is defined to increase as the frequency
increases. Return to FIG.
[0030]
Next, the regeneration process will be described. The control unit 12 causes the display unit 34
to display the list of music data 52 stored in the storage unit 14. Further, the control unit 12
inputs an instruction for selecting the music data 52 and an instruction for reproducing the
music data 52 (hereinafter collectively referred to as reproduction instruction ) via the
reception unit 10. The reproduction unit 24 acquires the music data 52 from the storage unit 14
and reproduces it in response to the reproduction instruction. The music data 52 is digitized
music data, and a known technique may be used to reproduce the music data 52, so the
description thereof is omitted here. In addition, although a plurality of music data 52 may be
stored in the storage unit 14, one music data 52 is shown here to clarify the drawing. Also,
hereinafter, the reproduced music data 52 is also referred to as "music data 52".
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[0031]
The filter unit 22 receives the level shift amount from the level shift unit 18, and receives the
correction value from the derivation unit 20. The filter unit 22 includes, for example, a plurality
of Infinite Impulse Response (IIR) filters corresponding to each frequency point, and sets a
correction value as a coefficient of each IIR filter. Furthermore, the filter unit 22 includes an
amplifier at the subsequent stage of the IIR filter, and sets the level shift amount as the
amplification factor of the amplifier. A FIR (Finite Impulse Response) filter may be provided
instead of the IIR filter, and at that time, the response characteristic to the correction value is set
as a tap coefficient. The filter unit 22 inputs the music data 52 and corrects the music data 52 by
the IIR filter and the amplifier. In particular, the amplifier performs amplification by the amount
of level shift by the amount of attenuation of the hearing characteristic data in the level shift unit
18. Hereinafter, the corrected music data 52 is also referred to as "music data 52". The filter unit
22 outputs the music data 52 to the SW unit 26.
[0032]
The SW unit 26 connects the filter unit 22 and the DAC unit 28 when an instruction for the
reproduction process is input from the control unit 12. That is, the SW unit 26 outputs the music
data 52 input from the filter unit 22 to the DAC unit 28. In the reproduction process, the DAC
unit 28 inputs music data 52 as a digital signal, and outputs music data 52 (hereinafter also
referred to as "music data 52") as an analog signal to the output unit 30. The output unit 30
outputs music data.
[0033]
In terms of hardware, this configuration can be realized with the CPU, memory, or other LSI of
any computer, and with software, it can be realized by a program loaded into the memory, etc.
Are drawing functional blocks. Therefore, it is understood by those skilled in the art that these
functional blocks can be realized in various forms by hardware only, software only, or a
combination thereof.
[0034]
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The operation of the playback apparatus 100 having the above configuration will be described.
FIG. 7 is a flowchart showing the procedure of correction processing in the playback device 100.
The level shift unit 18 substitutes 1 into the variable "i" (S10). Here, i corresponds to a frequency
point. If i is smaller than 9 (Y of S12), the level shift unit 18 derives the difference C [i] by
subtracting the ideal level [i] from the hearing level A [i] (S14). Also, the level shift unit 18 adds 1
to i (S16), and returns to step 12. On the other hand, if i is not smaller than 9 (N in S12), the level
shift unit 18 substitutes 1 for i again (S18), and substitutes C [i], that is, C [1] for Cmin (S20) ).
[0035]
If i is smaller than 8 (Y in S22) and C [i + 1] is not larger than Cmin (N in S24), the level shift unit
18 substitutes C [i + 1] for Cmin (S26). If C [i + 1] is larger than Cmin (Y in S24), step 26 is
skipped. Further, the level shift unit 18 adds 1 to i (S28), and returns to step S22. On the other
hand, if i is not smaller than 8 (N in S22), the level shift unit 18 stores Cmin (S30). Here, Cmin
corresponds to the level shift amount described above.
[0036]
The derivation unit 20 substitutes 1 into i (S32). If i is smaller than 9 (Y of S34), the derivation
unit 20 derives the above-mentioned difference value D [i] by subtracting Cmin from C [i] (S36).
Further, the derivation unit 20 adds 1 to i (S38), and returns to step S34. If i is not smaller than 9
(N in S34), the derivation unit 20 substitutes 1 for i again (S40). If i is smaller than 9 (Y in S42),
the derivation unit 20 derives the correction value EQ [i] by multiplying D [i] by the weighting
coefficient E [i] (S44). Further, the derivation unit 20 adds 1 to i (S46), and returns to step 42. If i
is not smaller than 9 (N in S42), the derivation unit 20 stores the correction value EQ [i] (S48).
[0037]
According to the embodiment of the present invention, when the user hears a tone signal, an
operation of pressing the button is requested, so that the user processing can be simplified.
Further, even with simple processing, hearing characteristic data can be acquired. Further, when
the level shift amount is derived based on the difference between the ideal characteristic data
and the hearing characteristic data, the hearing characteristic data is attenuated since the
hearing characteristic data is measured in a region where the volume level is larger than the ideal
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characteristic data. It is possible to derive only such level shift amount. In addition, since only the
level shift amount that attenuates the hearing characteristic data is derived, the derivation of the
level shift amount that attenuates the signal can be avoided. Further, since a level shift amount
which attenuates the hearing characteristic data is derived, it is possible to set a level shift
amount which is to be amplified in the amplifier. Further, since the level shift amount to be
amplified is set to the amplifier, the deterioration of the sound quality can be suppressed. In
addition, since only the level shift amount which is attenuated and finally amplified is derived at
first, there is no need to consider the opposite case, and the processing can be simplified.
[0038]
Second Embodiment In the second embodiment of the present invention, as in the first
embodiment, the correction value and the level shift amount are derived by examining the user's
hearing, and the music data is corrected based on them. It relates to the device. In the first
embodiment, one type of weighting factor is used to derive the correction value. On the other
hand, the playback device according to the second embodiment stores a plurality of types of
weighting coefficients. For example, multiple types of weighting factors correspond to multiple
types of music genres. When the reproduction device receives the reproduction instruction of the
music data, the reproduction device specifies the genre of the music data from the information
attached to the music data, and specifies the weight coefficient according to the specified genre.
Also, the reproduction device derives the correction value using the specified weighting factor,
and uses the correction value when reproducing the music data.
[0039]
FIG. 8 shows the configuration of a playback apparatus 100 according to a second embodiment
of the present invention. The reproduction apparatus 100 of FIG. 8 is of the same type as the
reproduction apparatus 100 of FIG. 1, but the inspection unit 32 includes a measurement unit
16, a level shift unit 18, a derivation unit 20, and a selection unit 36. , Inspection data 50, music
data 52, ideal characteristic data 54, a first weighting factor 56a, a second weighting factor 56b,
and an Nth weighting factor 56n. In the following, differences from the first embodiment will be
mainly described.
[0040]
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The measuring unit 16 and the level shift unit 18 derive the level shift amount in the inspection
process as in the first embodiment. Further, the deriving unit 20 derives a difference value in the
inspection process as in the first embodiment. However, the derivation unit 20 does not derive a
correction value in the inspection process. In the reproduction process, the control unit 12 inputs
a reproduction instruction as described above. The control unit 12 outputs a reproduction
instruction to the selection unit 36. When receiving the reproduction instruction, the selection
unit 36 specifies the music data 52 to be reproduced. Here, the music data 52 stored in the
storage unit 14 includes accompanying information. The accompanying information includes
information related to the music data 52. The information on the music data 52 is, for example,
information on the data format of the music data 52, the reproduction time, and the type. Here,
the information on the type is information on the genre of the music data 52.
[0041]
The selection unit 36 identifies the genre of the music data 52 while confirming the
accompanying information included in the identified music data 52. On the other hand, the
storage unit 14 stores a first weighting factor 56 a to an N-th weighting factor 56 n as a plurality
of weighting factors 56. Each of the plurality of weighting factors 56 is generated in advance to
correspond to music data 52 of different genres. The selection unit 36 selects the weighting
factor 56 according to the specified genre. That is, the selection unit 36 selects one of the
plurality of types of weighting factors 56 based on the type of music data 52 to be reproduced.
The selection unit 36 outputs the selected weighting factor 56 to the derivation unit 20. The
derivation unit 20 derives the correction value as in the first embodiment, using the weighting
factor 56 selected by the selection unit 36. In addition, since the subsequent processing is the
same as that of the first embodiment, the description is omitted here.
[0042]
The operation of the playback apparatus 100 having the above configuration will be described.
FIG. 9 is a flowchart showing the selection procedure in the selection unit 36. The selection unit
36 receives an instruction to select the music data 52 to be reproduced (S60). If there is
information on the type of music data 52 (Y at S62), the selection unit 36 selects a weighting
factor 56 according to the type (S64). On the other hand, if there is no information on the type of
the music data 52 (N at S62), the selection unit 36 selects a predetermined weighting factor 56
(S66).
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[0043]
According to the embodiment of the present invention, since a plurality of types of weighting
factors are stored and one weighting factor is selected according to the genre of music data to be
reproduced, weighting factors suitable for the genre of music data can be used. . In addition,
since weighting factors suitable for the genre of music data are used, correction values suitable
for the genre of music data can be generated. In addition, since the correction value suitable for
the genre of music data is used, correction suitable for music data can be performed. In addition,
since selection of weighting factors is automatically performed, it is possible to suppress
processing complexity.
[0044]
Third Embodiment Similar to the first embodiment, the third embodiment of the present
invention is a reproduction in which the correction value and the level shift amount are derived
by examining the user's hearing and the music data is corrected based on them. It relates to the
device. The reproduction apparatus according to the first embodiment or the second embodiment
stores a weighting factor. On the other hand, the reproducing apparatus according to the third
embodiment generates a weighting factor based on music data to be reproduced without storing
the weighting factor. Also, the reproduction apparatus derives a correction value using the
generated weighting factor, and uses the correction value when reproducing the music data.
[0045]
FIG. 10 shows the configuration of a playback apparatus 100 according to a third embodiment of
the present invention. The reproduction apparatus 100 of FIG. 10 is of the same type as the
reproduction apparatus 100 of FIG. 1, but the inspection unit 32 includes a measurement unit
16, a level shift unit 18, a derivation unit 20, and a generation unit 38. , Test data 50, first music
data 52a, second music data 52b, Nth music data 52n, and ideal characteristic data 54.
[0046]
The measuring unit 16 and the level shift unit 18 derive the level shift amount in the inspection
process as in the first embodiment. Further, the deriving unit 20 derives a difference value in the
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inspection process as in the first embodiment. However, the deriving unit 20 does not derive a
correction value in the inspection process, as in the second embodiment. In the reproduction
process, the control unit 12 inputs a reproduction instruction as described above. The control
unit 12 outputs the reproduction instruction to the generation unit 38. When receiving the
reproduction instruction, the generation unit 38 specifies the music data 52 to be reproduced.
Here, the first music data 52 a to the N-th music data 52 n are stored in the storage unit 14 as
the music data 52.
[0047]
The generation unit 38 extracts the identified music data 52 from the storage unit 14. The
generation unit 38 derives the above-described music waveform 204 by performing Fourier
transform on the extracted music data 52. Furthermore, the generation unit 38 extracts the value
corresponding to the desired frequency point from the music waveform 204, and derives the
weighting factor 56 by calculating the reciprocal of the extracted value. The generation unit 38
outputs the generated weighting factor 56 to the derivation unit 20. The derivation unit 20
derives the correction value as in the first embodiment, using the weighting factor 56 generated
by the generation unit 38. In addition, since the subsequent processing is the same as that of the
first embodiment, the description is omitted here.
[0048]
The operation of the playback apparatus 100 having the above configuration will be described.
FIG. 11 is a flowchart showing the procedure of reproduction processing in the reproduction
device 100. If the generation unit 38 does not receive the reproduction instruction (N in S80),
the generation unit 38 stands by. On the other hand, when receiving the reproduction instruction
(Y in S80), the generation unit 38 generates the weighting factor 56 (S82). The derivation unit
20 derives the correction value (S84).
[0049]
According to the embodiment of the present invention, since the weighting factor is generated
based on the audio signal to be reproduced, the weighting factor suitable for music data can be
used. In addition, since weighting factors suitable for music data are used, correction values
suitable for music data can be generated. In addition, since a correction value suitable for music
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data is used, correction suitable for music data can be performed. In addition, since the
generation of the weighting factor is automatically performed, the processing complexity can be
suppressed.
[0050]
The present invention has been described above based on the embodiments. It is understood by
those skilled in the art that this embodiment is an exemplification, and that various modifications
can be made to the combination of each component and each processing process, and such a
modification is also within the scope of the present invention. .
[0051]
In the first to third embodiments of the present invention, the hearing characteristic data is
measured in the area where the volume level is larger than that of the ideal characteristic data
54 in the measuring unit 16. However, for example, the volume level of the tone signal in the
measurement unit 16 may be set to any value, and a volume level that is lower than the ideal
characteristic data 54 may be used. At that time, the level shift unit 18 and the derivation unit 20
exclude the hearing level whose volume level is smaller than the ideal level from the correction
target. According to this modification, no correction for attenuating the music data 52 is made,
and the deterioration of the sound quality can be suppressed while improving the freedom of
setting the volume level of the tone signal.
[0052]
In the first to third embodiments of the present invention, the measuring unit 16 causes the
display unit 34 to display a screen as shown in FIG. 2 in the inspection process. However, not
limited to this, for example, the display unit 34 may display another screen in the inspection
process. FIG. 12 shows a screen displayed in a modification of the present invention. As shown,
the first reproduction level bar 130a to the eighth reproduction level bar 130h collectively
referred to as the reproduction level bar 130 are displayed. Each reproduction level bar 130
corresponds to a tone signal corresponding to each of the eight frequency points described
above. In the inspection process, the measurement unit 16 outputs a first tone signal
corresponding to the lowest frequency point. The user adjusts the volume level of the first tone
signal by raising and lowering the first current level pointer 132 on the first reproduction level
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bar 130a. The user depresses the next button 134 when the tone signal is at the loudest sound
level. Next, the measurement unit 16 outputs a second tone signal whose frequency point is
higher than that of the first tone signal. The user performs the same process as described above
by moving the second current level pointer 132b on the second reproduction level bar 130b up
and down. By repeating such processing, the measurement unit 16 acquires hearing
characteristic data corresponding to eight frequency points. According to this embodiment, since
the user adjusts the volume level by himself, it is possible to inspect in more detail the volume
level at which the tone signal can be smallest.
[0053]
It is a figure which shows the structure of the reproducing ¦ regenerating apparatus based on
Example 1 of this invention. It is a figure which shows the screen displayed on the display part of
FIG. It is a figure which shows the measurement result in the measurement part of FIG. It is a
figure which shows the ideal characteristic data memorize ¦ stored in the memory ¦ storage part
of FIG. FIGS. 5 (a) and 5 (b) are diagrams showing an outline of processing in the amplification
unit of FIG. It is a figure which shows the processing outline in the derivation ¦ leading-out part
of FIG. It is a flowchart which shows the procedure of the correction process in the reproducing ¦
regenerating apparatus of FIG. It is a figure which shows the structure of the reproducing ¦
regenerating apparatus based on Example 2 of this invention. It is a flowchart which shows the
selection procedure in the selection part of FIG. It is a figure which shows the structure of the
reproducing ¦ regenerating apparatus based on Example 3 of this invention. It is a flowchart
which shows the procedure of the reproduction ¦ regeneration processing in the reproducing ¦
regenerating apparatus of FIG. It is a figure which shows the screen displayed in the modification
of this invention.
Explanation of sign
[0054]
Reference Signs List 10 reception unit, 12 control unit, 14 storage unit, 16 measurement unit, 18
level shift unit, 20 derivation unit, 22 filter unit, 24 reproduction unit, 26 SW unit, 28 DAC unit,
30 output unit, 32 inspection unit, 34 Display unit, 50 test data, 52 music data, 54 ideal
characteristic data, 56 weighting factors, 100 playback devices.
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