TWI757763B - Electronic apparatus and sound field balancing method thereof for dual-channel - Google Patents

Abstract

An electronic apparatus and a sound field balancing method thereof for dual-channel are provided. In the method, a first delay time between two speakers in the space is determined, a second delay time of two speakers inside the system is determined, and overall delay time is determined according to the first and second delay times. The first delay is related to the locations of the two speakers at the electronic apparatus. The second delay time is related to phase shifts of multiple frequency bands based on the reception of the outputs of the two speakers. The overall delay is used to correct the delay time of the output of the two speakers. Accordingly, the sound pressure of dual-channel can be balanced.

Description

Electronic device and method for balancing two-channel sound field

The present invention relates to a sound field control technology, and in particular, to an electronic device and a method for balancing the two-channel sound field.

For electronic devices with two channels (for example, notebook computers, All-in-One (AIO) computers, or smart phones, etc.), although the sound outlets of the speakers are on the symmetrical sides of the body, the Due to the difference between the speaker unit and the internal design of the mechanism, the frequency responses of the left and right channel signals are inconsistent. Although the two-channel equalization (EQ) gain can be adjusted individually so that the signal strengths received by the microphones are very close, the sound field that the user actually feels in front of the electronic device is still offset. In addition, if only the phase offset of each frequency band is adjusted, the absolute value difference of the sound pressure difference of each frequency band will increase instead, which is not conducive to subsequent sound effect processing (eg, Dolby or DTS).

In view of this, the present invention provides an electronic device and a method for balancing the two-channel sound field, which can obtain an appropriate overall delay time based on the delay time of the space and the internal system, so that the sound pressure of the two-channel signal can be more balanced. status.

The two-channel sound field balancing method according to the embodiment of the present invention is applicable to an electronic device including two speakers. The two-channel sound field balance method includes (but is not limited to) the following steps: determining the first delay time of the spatial difference between the two speakers, determining the second delay time of the two speakers in the electronic device, and determining the first delay time and The second delay time determines the overall delay time. The first delay time is related to the positions of the two speakers respectively in the electronic device. The second delay time is related to the phase shift of the plurality of frequency bands obtained by collecting the two speakers. The overall delay time is used to correct the difference between the delay time of the sound played by the two speakers.

The electronic device of the embodiment of the present invention includes (but is not limited to) two speakers and a processor. The processor is coupled to the two speakers, and loads and executes several modules. These modules include a spatial delay estimation module, an internal delay estimation module, and an overall delay estimation module. The spatial delay estimation module determines the first delay time of the spatial difference between the two speakers, the internal delay estimation module determines the second delay time of the two speakers within the electronic device, and the overall delay estimation module is based on the first delay The time and the second delay time determine the overall delay time. The first delay time is related to the positions of the two speakers respectively in the electronic device. The second delay time is related to the phase shift of the plurality of frequency bands obtained by collecting the two speakers. The overall delay time is used to correct the difference between the delay time of the sound played by the two speakers.

Based on the above, the electronic device and the two-channel sound field level of the embodiment of the present invention The balance method integrates the position of the two speakers and the delay time caused by the transmission of the sound in the system, as the overall delay time difference between the sound of the two speakers in the electronic device. In this way, the embodiment of the present invention can reduce the influence of subsequent sound effect processing, reduce the comprehensive sound pressure gap, maintain the average result of the absolute value of the binaural sound pressure gap between each frequency band/frequency, and further reduce the standard deviation.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

100: Electronics

110, 120: Speaker

130: Storage

131: Spatial Delay Estimation Module

133: Internal delay estimation module

135: Overall delay estimation module

140: Radio

150: Processor

S210~S250, S410~S450, S510~S570: Steps

x , y , z : axes

( x _L , y _L , z _L ), ( x _R , y _R , z _R ), ( x _C , y _C , z _C ), ( x _m , y _m , z _m ): coordinates

PU: Reference position

PR: Radio position

PSR, PSL: Location

n _φ ( f ): initial phase delay

:初始延遲時間

: initial delay time

:第二延遲時間

: Second delay time

FIG. 1 is a block diagram of an electronic device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a method for balancing a two-channel sound field according to an embodiment of the present invention.

FIG. 3 is an example illustrating the positional relationship.

FIG. 4 is a flow chart of determining the internal correlation delay time of the system according to an embodiment of the present invention.

FIG. 5 is a flowchart of determining the minimum value of the ratio according to an embodiment of the present invention.

FIG. 1 is a block diagram of an electronic device 100 according to an embodiment of the present invention. Referring to FIG. 1 , the electronic device 100 may be a notebook computer, an AIO computer, a mobile phone, a tablet computer, a smart speaker, or a smart TV. The electronic device includes, but is not limited to, speakers 110 , 120 , storage 130 , radio 140 and processor 150 .

Speakers 110, 120 may be speakers or loudspeakers. In one embodiment, The speakers 110, 120 correspond to the left and right channels, respectively, to form a two-channel speaker.

The storage 130 may be any type of fixed or removable random access memory (RAM), read only memory (ROM), flash memory, conventional hard disks (Hard Disk Drive, HDD), Solid-State Drive (Solid-State Drive, SSD) or similar components. In one embodiment, the storage 130 is used to record code, software modules (eg, the spatial delay estimation module 131, the internal delay estimation module 133, the overall delay estimation module 135, etc.), audio signals, The weight value, delay time, distance, position offset, phase offset and other data or files will be described in detail in subsequent embodiments.

The microphone 140 may be a microphone of a dynamic type, a condenser type, or an electret condenser (Electret Condenser). A combination of electronic components, analog-to-digital converters, filters, and audio processors that convert them into sound signals.

The processor 150 is coupled to the speakers 110, 120, the storage 130 and the radio 140. The processor 150 may be a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessors ( Microprocessor), digital signal processor (Digital Signal Processor, DSP), programmable controller, application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC) or other similar components or a combination of the above components. In one embodiment, the processor 150 is used to execute all or part of the operations of the electronic device 100 , and can load and execute various software modules, files and data recorded in the storage 130 .

Hereinafter, the method according to the embodiment of the present invention will be described in conjunction with various devices, components and modules in the electronic device 100 . Each process of the method can be adjusted according to the implementation situation, and is not limited to this.

FIG. 2 is a flowchart of a method for balancing a two-channel sound field according to an embodiment of the present invention. Referring to FIG. 2 , the spatial delay estimation module 131 determines the first delay time of the spatial difference between the two speakers 110 , 120 (step S210 ). Specifically, the first delay time is related to the delay time caused by the positions of the speakers 110 and 120 respectively in the electronic device 100 . If the positions of the two-channel speakers 110 and 120 are not completely symmetrical to the body of the electronic device 100 , the unbalanced sound field can be corrected by time delay.

In one embodiment, the spatial delay estimation module 131 determines the position offset of the two speakers 110 , 120 from the reference position. The reference position is related to the listening position of the user, and it is assumed that the user's head corresponds to the center of the body of the electronic device 100 .

FIG. 3 is an example illustrating the positional relationship. Please refer to FIG. 3 , assuming that the space where the electronic device 100 is located forms a coordinate system with three orthogonal axes x , y , and z , the coordinates of the position PSL of the speaker 110 are ( x _L , y _L , z _L ), the position PSR of the speaker 120 The coordinates of ( x _R , y _R , z _R ), and the coordinates of the estimated reference position PU where the user’s head is located are ( x _C , y _C , z _C ) (that is, the user’s listening position, or the center point).

，以此類推其他軸y、z及揚聲器120，以得出揚聲器110在y軸上與參考位置PU的相對距離為

、揚聲器110在z軸上與參考位置PU的相對距離為

、揚聲器120在x軸上與參考位置PU的相對距離為

、揚聲器120在y軸上與參考位置PU的相對距離為

及揚聲器120在z軸上與參考位置PU的相對距離為

。接著，空間延遲估測模組131將兩揚聲器110,120在三軸x、y、z上與參考位置PU的相對距離的差異加總，並據以決定雙聲道揚聲器110,120所處位置的位置偏移D _C ，其數學式表示如下：

In one embodiment, the spatial delay estimation module 131 respectively determines the relative distances between the speakers 110 and 120 on the three axes x , y and z of the spatially corresponding coordinate system and the reference position PU, and according to the three axes of the speakers 110 and 120 The sum of the distance differences between the relative distances at x , y , z from the reference position PU determines the position offset. Taking the x -axis as an example, the relative distance between the speaker 110 and the reference position PU is

, and so on for other axes y , z and the speaker 120, to obtain the relative distance between the speaker 110 and the reference position PU on the y -axis as

, the relative distance between the speaker 110 and the reference position PU on the z -axis is

, the relative distance between the speaker 120 and the reference position PU on the x -axis is

, the relative distance between the speaker 120 and the reference position PU on the y -axis is

And the relative distance between the speaker 120 and the reference position PU on the z -axis is

. Next, the spatial delay estimation module 131 sums up the differences in the relative distances between the two speakers 110 , 120 on the three axes x , y , and z and the reference position PU, and determines the position offset of the positions of the two-channel speakers 110 , 120 accordingly. D _C , its mathematical expression is as follows:

，其中

為第一時間延遲(即，揚聲器110,120在空間中的所處位置所造成的時間延遲)(單位為取樣點數)，F _S 為取樣頻率，且C _S 為聲音速度。若第一時間延遲的數值為-X，則代表揚聲器110延遲X個取樣點；若第一時間延遲的數值為+X，則代表揚聲器120延遲X個取樣點。 In addition, the spatial delay estimation module 131 can determine the offset of the time sampling point according to the position offset DC , that is, the first time delay, and its mathematical _formula is expressed as follows:

,in

is the first time delay (ie, the time delay caused by the positions of the speakers 110, 120 in space) (unit is the number of sampling points), F _S is the sampling frequency, and C _S is the speed of sound. If the value of the first time delay is -X, it means that the speaker 110 is delayed by X sampling points; if the value of the first time delay is +X, it means that the speaker 120 is delayed by X sampling points.

Returning to FIG. 2 , the internal delay estimation module 133 determines the second delay time difference between the two speakers 110 , 120 inside the electronic device 100 (step S230 ). Specifically, before the sound signal is played by the speakers 110 and 120 , it may be transmitted or received by the mechanism of the electronic device 100 through one or more circuits (eg, DSP, or codec, etc.). The design (collectively referred to as the non-spatial appearance factor) affects the delay time between the signals played by the two speakers 110 , 120 . In the embodiment of the present invention, the second delay time is related to the phase shifts of multiple frequency bands obtained by collecting sound from the two speakers 110 and 120 through the microphone 140 .

In order to obtain the influence caused by the system, the internal delay estimation module 133 needs to know the time offset caused by the relative positions of the speakers 110 , 120 and the receiver 140 first. In one embodiment, the internal delay estimation module 133 determines a third delay time between the two speakers 110 , 120 spatially corresponding to the difference between the receiver 140 . Similar to the embodiment of the first delay time, but this embodiment changes the reference position (corresponding to the listening position of the user) to the position of the microphone 140 .

，其中

、

、

分別是揚聲器110在x、y、z軸上與收音位置PR的相對距離，且

、

、

分別是揚聲器120在x、y、z軸上與收音位置PR的相對距離。即，位置偏移D _m 是，兩揚聲器110,120在三軸x、y、z上與收音位置PR的相對距離之間的距離差之總和。此外，時間偏移

(即，第三延遲時間)的數學表示式為：

Taking FIG. 3 as an example, the coordinates of the sound-receiving position PR of the microphone 140 are ( x _m , y _m , z _m ), then the mathematics of the positional offset D _m caused by the two-channel speakers 110 , 120 and the microphone 140 in space The expression is:

,in

,

,

are the relative distances between the speaker 110 and the sound collection position PR on the x , y, and z axes, respectively, and

,

,

are the relative distances between the speaker 120 and the sound collection position PR on the x , y, and z axes, respectively. That is, the position shift D _m is the sum of the distance differences between the relative distances of the two speakers 110 , 120 and the sound collection position PR on the three axes x , y , and z . In addition, time offset

(ie, the third delay time) is mathematically expressed as:

The internal delay estimation module 133 can correct the delay time of the two channels according to the third delay time, and perform subsequent phase offset adjustment operations. Figure 4 is based on this A flow chart of determining the internal correlation delay time of the system according to an embodiment of the invention. Referring to FIG. 4 , the internal delay estimation module 133 determines the initial phase offset of each frequency band (step S410 ). In one embodiment, the internal delay estimation module 133 plays the two test signals through the two speakers 110 and 120 according to the third delay time. The test signal adopts the pink noise of the general measurement sound field (but may also be white noise or other sound signals), and the two test signals are respectively subject to the specified forward direction and surround sound.

(n)和

(n)。若僅透過揚聲器110播放左聲道訊號，則收音器140所接收到的各頻率的音壓振幅為

(f)，其中f為頻率並代表某一頻帶的中心頻率。而若僅透過揚聲器120播放右聲道訊號，則收音器140所接收到的各頻率的音壓振幅為

(f)。 The two-channel signals x _L ( n ), x _R ( n ) played through the speakers 110 and 120 respectively are the same (ie, x _L ( n ) = x _R ( n )), and the two-channel signals x _L ( n ), After x _R ( n ) is corrected by the EQ gain, the left and right channel test signals become

( n ) and

( n ). If only the left channel signal is played through the speaker 110, the sound pressure amplitude of each frequency received by the radio 140 is

( f ), where f is the frequency and represents the center frequency of a certain frequency band. And if only the right channel signal is played through the speaker 120, the sound pressure amplitude of each frequency received by the radio 140 is

( f ).

)為負值，則正向方向的測試訊號

(n)(對應到左聲道)，

(n)(對應到右聲道)為

及x _R (n)。若第三延遲時間為正值，則正向方向的測試訊號

(n),

(n)為x _L (n)及

。此外，環繞音效的測試訊號

(n)(對應到左聲道)，

(n)(對應到右聲道)為

(n)及-

(n)。另一方面，假設揚聲器110,120播放正向方向的測試訊號，則收音器140所接收到的各頻率音壓振幅為P ^C (f)。假設揚聲器110,120播放環繞音效的測試訊號，則收音器140所接收到的各頻率音壓振幅為P ^S (f)。 The internal delay estimation module 133 can modify the test signal according to the third delay signal. Assuming a third delay time (ie, time offset

) is a negative value, the test signal in the positive direction

( n ) (corresponding to the left channel),

( n ) (corresponding to the right channel) is

and xR ₍ n ). If the third delay time is positive, the test signal in the forward direction

( n ),

( n ) is x _L ( n ) and

. In addition, the test signal for surround sound

( n ) (corresponding to the left channel),

( n ) (corresponding to the right channel) is

( n ) and -

( n ). On the other hand, if the speakers 110 and 120 play the test signal in the forward direction, the sound pressure amplitude of each frequency received by the receiver 140 is P ^C ( f ). Assuming that the speakers 110 and 120 play the test signal of surround sound, the sound pressure amplitude of each frequency received by the receiver 140 is P ^S ( f ).

(f)+

(f)。因此，正向方向對應的音壓振幅P ^C (f)的最大值為

(f)+

(f)並越接近理想狀態。而相位偏移φ(f)越小，則音壓振幅P ^C (f)會越大。因此，正向方向的相位偏移φ ^C (f)的數學表示式為：

，即正向方向的相位偏移為直角三角形的鄰邊與斜邊之間的夾角，且假設音壓振福最大值作為此夾角的斜邊，某一頻率的音壓振福作為此夾角的鄰邊。 The internal delay estimation module 133 picks up the two test signals (ie, the corrected test signals) played according to the third delay time to determine the initial phase offset of those frequency bands. Specifically, assuming a completely ideal situation where the phase offset φ( f ) is zero, when the test signal in the forward direction is played, theoretically the two-channel signals will be mutually at the center point (the reference position PU in Figure 3). Superposition, as if the sound pressure amplitudes of the two channels are added together

( f )+

( f ). Therefore, the maximum value of the sound pressure amplitude P ^C ( f ) corresponding to the forward direction is

( f )+

( f ) and the closer it gets to the ideal state. And the smaller the phase offset φ( f ) is, the larger the sound pressure amplitude P ^C ( f ) will be. Therefore, the mathematical expression for the phase shift φ ^C ( f ) in the forward direction is:

, that is, the phase shift in the forward direction is the angle between the adjacent side and the hypotenuse of the right triangle, and the maximum value of the sound pressure vibration is assumed as the hypotenuse of this angle, and the sound pressure vibration at a certain frequency is used as the angle. adjacent.

，即環繞音效的相位偏移為直角三角形的鄰邊與斜邊之間的夾角，且假設音壓振福最大值作為此夾角的斜邊，某一頻率的音壓振福作為此夾角的對邊。 The relationship between the surround sound and the forward direction is just the opposite. When playing the test signal of the surround sound, theoretically, the two-channel signals will cancel each other at the center point, and the sound pressure amplitude will become zero. Therefore, the phase offset φ ^S ( f ) of the surround sound is:

, that is, the phase offset of the surround sound is the angle between the adjacent side and the hypotenuse of the right triangle, and it is assumed that the maximum value of the sound pressure vibration is the hypotenuse of this angle, and the sound pressure vibration of a certain frequency is used as the pair of this angle. side.

若不考慮雙聲道各自播放時的音壓振幅，則各頻帶相位偏移量可表達為

The internal delay module 133 can determine the initial phase delay n _φ ( f ) of each frequency band according to the forward direction and the phase offset corresponding to the surround sound effect, and its mathematical expression is:

If the sound pressure amplitude of the two-channel playback is not considered, the phase offset of each frequency band can be expressed as

。由此可知，相較於個別調整不同頻帶的相位偏移，本發明實施例是對這些頻帶採用加權平均，以縮小綜合音壓差距。 Next, the internal delay estimation module 133 determines the initial delay time according to the weights corresponding to the initial phase offsets of those frequency bands (step S430 ). Specifically, the weights corresponding to the initial phase offsets of those frequency bands are related to human auditory characteristics. Since human hearing has different sensitivities to different frequencies (for example, 2000 Hz to 4000 Hz is the highest, and the rest are attenuated in different proportions), the internal delay estimation module 133 assigns different weights w ( f ) to the phase offsets of each frequency band , and the phase offset corresponding to the frequency band with the higher output power P ( f ) of the electronic device 100 can also obtain a larger proportion. That is, the higher the output power, the higher the weight; the lower the output power, the lower the weight. Accordingly, the mathematical expression of the initial delay time is:

. It can be seen from this that, compared to individually adjusting the phase offsets of different frequency bands, the embodiment of the present invention adopts a weighted average for these frequency bands to narrow the comprehensive sound pressure gap.

Next, the internal delay estimation module 133 can determine the second delay time according to the deviation of the power state. In one embodiment, the internal delay estimation module 133 respectively picks up the two test signals through the microphone 140 and obtains the received power corresponding to the two test signals respectively. In some embodiments, these received powers may be adjusted to each by A-weighting, Perceived Noise Level, or Weighted Equivalent continuous Perceived Noise Level. The frequencies are given corresponding weights.

，其中

為接收功率的比值，

為正向方向對應的接收功率，

為環繞音效對應的接收功率，且

為延遲時間。值得注意的是，比值

越小，其所對應到的延遲時間

越接近雙聲道平衡狀態。由此可知，第二延遲時間與比值最小值相關。 The internal delay estimation module 133 can determine the second delay time according to the ratio of the received power corresponding to the two test signals. In one embodiment, the (power) ratio takes the received power corresponding to the test signal in the forward direction as the denominator and the received power corresponding to the surround sound test signal as the numerator, and its mathematical expression is as follows:

,in

is the ratio of the received power,

is the received power corresponding to the forward direction,

is the received power corresponding to the surround sound, and

for the delay time. It is worth noting that the ratio

The smaller, the corresponding delay time

The closer it is to a two-channel balanced state. From this, it can be seen that the second delay time is related to the minimum value of the ratio.

±1、…、

±N，其中N是預設值(代表量測的範圍)並為正整數。也就是說，透過揚聲器110,120播放的雙聲道訊號可分別經初始延遲時間及相鄰延遲時間修正，且收音器140對不同延遲時間對應的兩測試訊號分別錄製，以取得兩測試訊號在這些延遲時間下的接收功率。 The internal delay estimation module 133 may determine the second delay time according to the ratio of the initial delay time and the received power corresponding to one or more adjacent delay times (step S450 ). Specifically, the internal delay estimation module 133 can take the aforementioned initial delay time as the center, and play two test signals through the two speakers 110 , 120 respectively according to those adjacent delay times. The adjacent delay time is different from the initial delay time. For example, the adjacent delay time is

±1,…,

± N , where N is a preset value (representing the measurement range) and is a positive integer. That is to say, the two-channel signals played through the speakers 110 and 120 can be respectively modified by the initial delay time and the adjacent delay time, and the radio 140 records the two test signals corresponding to different delay times respectively, so as to obtain the two test signals at these delays. received power over time.

。 Next, the internal delay estimation module 133 may determine the minimum value of the ratio according to the ratio of the initial delay time to the received power corresponding to those adjacent delay times. FIG. 5 is a flowchart of determining the minimum value of the ratio according to an embodiment of the present invention. Referring to FIG. 5 , the internal delay estimation module 133 determines the ratio of the initial delay time to the received power corresponding to the adjacent delay time (step S510 ). Taking mathematical calculation as an example, the initial delay time and adjacent delay time will be substituted into the delay time of equation (10) respectively

.

Assuming the preset N value, the internal delay estimation module 133 determines whether the minimum value of the ratio is outside the preset adjacent delay time (step S530 ). The delay time is sequentially increased or decreased with the initial delay time as the center, and the change trend of the corresponding ratio is judged. If the change trend has a bottom value, it means that the minimum value is within the preset range, and the internal delay estimation module 133 determines the second delay time by interpolation (step S550 ).

(是初始延遲時間與那些相鄰延遲時間的其中一者)決定兩第二相鄰延遲時間

±1。這兩第二相鄰延遲時間與該待評估延遲時間的相距時間相同(本實施例是一個取樣點，但也可能是兩個或其他個數的取樣點)，且這兩第二相鄰延遲時間中的一者不同於另一者。 In one embodiment, the internal delay estimation module 133 determines the delay time to be evaluated corresponding to the minimum value among the ratios of the initial delay time and the received power corresponding to those adjacent delay times

(which is one of the initial delay time and those adjacent delay times) determines the two second adjacent delay times

±1. The distance between the two second adjacent delay times and the delay time to be evaluated is the same (this example is one sampling point, but it may also be two or other sampling points), and the two second adjacent delay times are One of the times is different from the other.

、

、

透過內差方式求出比值最小值。接著，內部延遲估測模組133可依據此比值最小值對應的延遲時間決定第二延遲時間

。 The internal delay estimation module 133 may determine the minimum value of the ratio through interpolation between the ratio of the delay time to be estimated and the received power corresponding to the two second adjacent delay times. That is, the ratio of

,

,

Find the minimum value of the ratio by means of inner difference. Then, the internal delay estimation module 133 can determine the second delay time according to the delay time corresponding to the minimum value of the ratio

.

±(N+1)、或

±(N+2)等)對應的接收功率的比值(步驟S570)，直到得出最小值或到達遞迴上限(即，由初始延遲時間的中心往外擴展次數的上限)。最後，同樣透過內插求出合適的延遲時間。 In some extreme cases of offset, the extreme value (minimum value) may exceed a preset range (eg, the aforementioned N value). If the change trend of the ratio does not have a bottom value, it means that the minimum value is not within the preset range, and the internal delay estimation module 133 determines another adjacent delay time (different from the adjacent delay time preset in step S510, for example,

±( N +1), or

±( N +2), etc.) corresponding to the ratio of the received power (step S570) until the minimum value is obtained or the upper limit of recursion (ie, the upper limit of the number of times to expand outward from the center of the initial delay time) is reached. Finally, the appropriate delay time is also obtained through interpolation.

It should be noted that, in other embodiments, the internal delay estimation module 133 can also directly obtain the minimum value of the ratio through other minimization algorithms, and then calculate the second delay time.

。而此整體延遲時間可用於修正兩揚聲器110,120播放聲音所相差的延遲時間。例如，若整體延遲時間n _D 為正值，則對應於揚聲器120的右聲道訊號將需要延遲n _D 。反之(即，負值)，則為對應於揚聲器110的左聲道訊號需要延遲n _D 。藉此，可提供適當的延遲時間來達成音場平衡。 Returning to FIG. 2 , the overall delay estimation module 135 can determine the overall delay time according to the first delay time and the second delay time (step S250 ). Specifically, the embodiment of the present invention comprehensively considers the delay time caused by space and non-space, and the overall delay time of the audio signal output by the integrated electronic device 100 is the sum of the two delay times:

. The overall delay time can be used to correct the delay time difference between the sound played by the two speakers 110 and 120 . For example, if the overall delay time n _D is a positive value, the right channel signal corresponding to the speaker 120 will need to be delayed by n _D . On the contrary (ie, a negative value), the left channel signal corresponding to the speaker 110 needs to be delayed by n _D . In this way, an appropriate delay time can be provided to achieve sound field balance.

本發明實施例的綜合音壓差距縮小在1dB之內，且能維持雙聲道音壓差距絕對值在各頻率間的平均結果，並降低標準差。須說明的是，表(1)中的測試結果僅是用於範例說明，且可能因為實驗因素的改變而不同。 Table (1) is a comparison table of two-channel sound pressure characteristics: Table (1)

The comprehensive sound pressure difference of the embodiment of the present invention is reduced within 1 dB, and the average result of the absolute value of the two-channel sound pressure difference between frequencies can be maintained, and the standard deviation can be reduced. It should be noted that the test results in Table (1) are for illustrative purposes only, and may vary due to changes in experimental factors.

To sum up, in the electronic device and the method for balancing the two-channel sound field in the embodiment of the present invention, in order to obtain a suitable delay time for the whole system and achieve a relatively balanced state of the sound pressure of the two-channel signal, the present invention Embodiments consider two delay times. One is the delay time caused by the position of the binaural speakers, and the other is the time delay caused by the internal system of the electronic device. After the two are integrated, they can be used as the overall delay time.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

S210~S250: Steps

Claims (10)

A two-channel sound field balancing method, suitable for an electronic device including two speakers, the two-channel sound field balancing method comprising: determining a first delay time that the two speakers differ in space, wherein the first delay time The time is related to the positions of the two speakers respectively in the electronic device; determining a second delay time of the difference between the two speakers in the electronic device, wherein the second delay time is related to the frequency bands obtained by the two speakers. phase shift; and determine an overall delay time according to the first delay time and the second delay time, wherein the overall delay time is used to correct the delay time difference between the two speakers playing sound, wherein the electronic device further includes a radio and the step of determining the second delay time of the difference between the two speakers in the electronic device includes: determining a third delay time of the two speakers in the space corresponding to the difference of the receiver, wherein the third delay time relative to the positions of the two speakers relative to the receiver; play two test signals through the two speakers according to the third delay time, wherein the two test signals are respectively subjected to a designated forward direction and a surround sound effect; respectively through the receiver The two test signals are radioed, and the received powers corresponding to the two test signals are obtained respectively; and the second delay time is determined according to the ratio of the received powers corresponding to the two test signals. The two-channel sound field balancing method as claimed in claim 1, wherein the step of determining the first delay time of the spatial difference between the two speakers comprises: determining a position offset between the two speakers and a reference position, wherein The reference position is related to the listening position of the user, and the step of determining the position offset includes: respectively determining the relative distance between each speaker and the reference position on three axes of the spatially corresponding coordinate system; and according to the two speakers The position offset is determined by the sum of the distance differences between the relative distances from the reference position on the three axes; and the first delay time is determined according to the position offset. The two-channel sound field balancing method according to claim 1, wherein the step of playing the two test signals through the two speakers according to the third delay time comprises: determining a an initial delay time, wherein the two test signals played according to the third delay time are collected to determine the initial phase offsets of the frequency bands, and the weights corresponding to the initial phase offsets of the frequency bands are related to human hearing characteristics; and The initial delay time is taken as the center, and the two test signals are played through the two speakers according to at least one adjacent delay time, wherein the at least one adjacent delay time is different from the initial delay time. The two-channel sound field balancing method according to claim 3, wherein the ratio takes the received power corresponding to the test signal in the forward direction as the denominator and the received power corresponding to the surround sound test signal as the numerator, and according to the The step of determining the second delay time by the ratio of the received power corresponding to the two test signals includes: A ratio minimum value is determined according to the ratio of the initial delay time and the received power corresponding to the at least one adjacent delay time; and the second delay time is determined according to the delay time corresponding to the ratio minimum value. The two-channel sound field balance method according to claim 4, wherein the step of determining the minimum value of the ratio comprises: according to the minimum value of the ratio of the initial delay time and the received power corresponding to the at least one adjacent delay time. The to-be-evaluated delay time determines two second adjacent delay times, wherein the two second adjacent delay times and the to-be-evaluated delay time are separated by the same time, and one of the two second adjacent delay times is different from the other and the ratio of the to-be-evaluated delay time and the received power corresponding to the two second adjacent delay times to determine the minimum value of the ratio through interpolation. An electronic device includes: two speakers; a processor, coupled to the two speakers, loads and executes a plurality of modules, the modules include: a spatial delay estimation module for determining the two speakers in a space a first delay time of the difference, wherein the first delay time is related to the positions of the two speakers respectively in the electronic device; an internal delay estimation module to determine a second delay of the difference of the two speakers inside the electronic device time, wherein the second delay time is related to the phase shifts of multiple frequency bands obtained from the two speakers; and an overall delay estimation module, according to the first delay time and the second delay time The delay time determines an overall delay time, wherein the overall delay time is used to correct the delay time difference between the sound played by the two speakers; and a radio, wherein the internal delay estimation module determines that the two speakers correspond in the space to A third delay time that differs between the receivers, according to the third delay time, the two test signals are played through the two speakers, the two test signals are respectively received through the receiver, and the corresponding received powers of the two test signals are obtained respectively, And the second delay time is determined according to the ratio of the received power corresponding to the two test signals, wherein the third delay time is related to the positions of the two speakers relative to the receiver, and the two test signals are respectively subject to a designated forward direction and surround sound. The electronic device of claim 6, wherein the spatial delay estimation module determines the relative distance between each speaker and a reference position on three axes of the spatially corresponding coordinate system, according to the three axes of the two speakers. The sum of the distance differences between the relative distances from the reference position and the reference position determines a position offset, wherein the reference position is related to the listening position of the user, and determines the first delay time according to the position offset. The electronic device of claim 6, wherein the internal delay estimation module determines an initial delay time according to the weights corresponding to the initial phase offsets of the frequency bands, takes the initial delay time as a center, and respectively according to the at least An adjacent delay time is used to play the two test signals through the two speakers, wherein the two test signals played according to the third delay time are collected to determine the initial phase offset of the frequency bands, and the initial phase offset of the frequency bands The weight corresponding to the shift is related to human auditory characteristics, and the at least one adjacent delay time is different from the initial delay time. The electronic device as claimed in claim 8, wherein the ratio takes the received power corresponding to the test signal in the forward direction as the denominator and the received power corresponding to the surround sound test signal as the numerator, and the internal delay estimation module is based on A ratio of the initial delay time to the received power corresponding to the at least one adjacent delay time determines a minimum ratio value, and determines the second delay time according to the delay time corresponding to the minimum ratio value. The electronic device as claimed in claim 9, wherein the internal delay estimation module determines the second delay time according to the to-be-evaluated delay time corresponding to the minimum value of the ratio of the initial delay time and the received power corresponding to the at least one adjacent delay time Two adjacent delay times, and the ratio of the to-be-evaluated delay time and the received power corresponding to the two second adjacent delay times is determined by interpolation to determine the minimum value of the ratio, wherein the two second adjacent delay times and the to-be-evaluated delay time The separation times of the delay times are the same, and one of the two second adjacent delay times is different from the other.

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