TW201928654A - Audio signal playing device and audio signal processing method - Google Patents

Abstract

An audio signal playing device includes a sensor and a processor. The sensor is configured to detect an angle between an audio signal playing plane and a reference plane. The processor is coupled to the sensor and configured to receive a set of input audio signals and information regarding the angle, and process the input audio signals according to the information regarding the angle to generate a set of output audio signals.

Description

Audio signal playing device and corresponding audio signal processing method

The present invention relates to an audio signal playback apparatus and a corresponding audio signal processing method for correcting a shift in sound source position perceived by a listener due to an angular change between a listener and an earphone or an audio playback device.

The sound is emitted from various points in the three-dimensional space, so that a person who hears the sound can use various auditory cues to determine which spatial point the sound originated from. For example, the human brain processes sound localization prompts quickly and efficiently, such as interaural delay (ie, the time delay between sounds impinging on each tympanic membrane), the sound pressure level difference between the listener's ears, and the impact. The sounds of the left and right ears are phase shifted in the sense, etc., to accurately identify the origin of the sound. Based on this feature, many audio playback devices or systems can use a special audio processing method and/or corresponding circuit to play multi-channel messages through a two-channel system, as long as the listener's ears are exactly right two. The surround speaker, or the listener sitting at the intersection of the two-channel speaker's axis, or listening to it with headphones, can feel the surround effect. In this way, a multi-channel virtual environment can be created through the two-channel sound output, so that the multi-channel surround effect is presented through two channels.

However, in actual use, the listener’s ear and earphones or sound The angle between the dialing devices may still be offset, causing the sound source that the listener feels to be positioned incorrectly, or the sound being heard may be distorted.

For example, in order to fit the user's auricle when wearing headphones on the market, for the different needs of each person, the slight flexibility in the angle can be adjusted, but the sound source signal is not matched with the user. The angle of the wear varies, so the audio signal that the user feels will vary depending on the angle at which the headphones are worn.

In order to solve the above problems, the present invention provides an audio signal playing device and a corresponding audio signal processing method, which can overcome the sound source positioning error that the listener feels due to the angle change between the listener and the earphone or the audio playback device. Or the problem that the heard sound will be distorted.

The invention discloses an audio signal playing device, which comprises an inductor and a processor. The sensor is configured to detect an angle between at least one sound plane of the audio signal playing device and a reference plane. The processor is coupled to the sensor for receiving a set of input audio signals, and receiving the information of the included angles, and processing the input audio signals according to the angle information to generate a set of output audio signals.

The invention discloses a method for processing an audio signal, comprising: receiving a set of input audio signals; detecting an angle between at least one sound plane of a sound signal playing device and a reference plane; and processing the input audio signal according to the information of the angle, A set of output audio signals is generated to compensate for a change in position of at least one of the equivalent sound sources simulated by the input audio signal due to the included angle.

100‧‧‧Audio signal playback device

110‧‧‧Optical signal input circuit

120‧‧‧ processor

130‧‧‧Audio signal output circuit

140‧‧‧ sensor

Lt, Rt, Lout, Rout, X _C , X _L , X _R , X _RL , X _RR Y _{C L} , Y _CR , Y _L , Y _R , Y _RL , Y _RR ‧‧‧ audio signals

Angle between school sound sources such as θ _L , θ _R , θ _RL , θ _RR ‧‧‧

△θ _L , Δθ _R ‧‧‧ angle change

1 is a block diagram showing an example of an audio signal playback apparatus according to an embodiment of the present invention.

Figure 2 is a schematic view showing an angle according to an embodiment of the present invention.

Figure 3 is a flow chart showing a method of processing an audio signal according to an embodiment of the present invention.

Figure 4 is a graph showing the relationship between the included angle and the included angle of a multi-channel audio signal according to an embodiment of the present invention.

In order to make the objects, features and advantages of the present invention more comprehensible, the specific embodiments of the invention are set forth in the accompanying drawings. The intention is to illustrate the spirit of the invention and not to limit the scope of the invention, it being understood that the following embodiments can be implemented by software, hardware, firmware, or any combination of the above.

1 is a block diagram showing an example of an audio signal playback apparatus according to an embodiment of the present invention. The audio signal playback device 100 can include an audio signal input circuit 110, a processor 120, an audio signal output circuit 130, and an inductor 140. According to an embodiment of the invention, the audio signal playback device 100 can be a headset device, an audio signal player, or a virtual reality wear device. For example, a left-channel earphone and a right-channel earphone of a headphone device or a virtual reality earphone device can be configured with an audio signal broadcast as shown in FIG. The device 100 is placed.

The audio signal input circuit 110 is configured to receive a set of input audio signals (Rt, Lt) transmitted by a transmitting end (not shown). The sensor 140 is configured to detect an angle between at least one sound plane of the audio signal playing device 100 and a reference plane. For example, as shown in FIG. 2, in the embodiment where the audio signal playing device 100 is disposed in a left channel earphone or a right channel earphone, the reference plane may be defined according to the user's pinna. One of the planes or a plane of the user's auricle, or a horizontal plane or a vertical plane, and the outer casing of the audio signal playback device 100 defines a plane of sound (ie, a plane in which the audio signal is played). Therefore, the angle θ can represent an angle between one of the sound planes of one of the audio signal playing devices and one of the receiving planes of the listener. In Fig. 2, the two axes represent the reference plane and the sound plane to show the angle θ between the two planes, wherein the axis representing the sound plane may be any one of the sound planes passing through the earphone, or according to the audio One of the shell shapes of the signal playback device 100 defines one of the X-axis, the Y-axis, or the Z-axis.

According to an embodiment of the present invention, the sensor 140 may be a direction sensor, an electronic compass sensor (E-compass) or an acceleration sensor (G-sensor), wherein the unit of the sensor 140 output data may be angle. More specifically, the sensor 140 can continuously detect an angle θ between one of the sound planes of the audio signal playing device 100 and one of the listening planes of the listener, or the sensor 140 can continuously detect at least one of the audio signal playing devices 100. The axis (e.g., the sound plane of the audio signal playback device 100 or one of the axes of the sound plane of the audio signal playback device 100) is at an angle to one of the reference planes.

The processor 120 is coupled to the sensor 140, and receives the input audio signal (Rt, Lt), and receives the information of the angle θ, and according to the information of the angle θ The input audio signal (Rt, Lt) is processed to generate a set of output audio signals (Rout, Lout). According to an embodiment of the invention, the input audio signal (Rt, Lt) may be a set of two-channel audio signals, wherein Rt may represent a right channel audio signal and Lt may represent a left channel audio signal. According to an embodiment of the invention, the output audio signal (Rout, Lout) may also be a set of two-channel audio signals, wherein Rout may represent a right channel audio signal, and Lout may represent a left channel audio signal.

According to an embodiment of the present invention, before outputting the audio signal, the processor 120 may process the input audio signal (Rt, Lt) according to the information of the angle θ to generate an output audio signal (Rout, Lout) for compensating or correcting the cause. The angle θ causes a change or offset in position of one of the at least one equivalent sound source simulated by the input audio signal. In addition, since the transmitting end can continuously provide the input audio signal (Rt, Lt), and the listener may rotate the head during the listening process or adjust the wearing manner, angle, etc. of the audio signal playing device 100, the sensor 140 or the processor 120 The change or offset of the included angle θ can be continuously detected, and the processor 120 continuously processes the subsequently received input audio signal (Rt, Lt) according to the change or offset of the included angle θ to compensate or correct the subsequent angle θ. The change or offset causes a change or offset in position of at least one equivalent sound source that the input audio signal simulates. The following paragraphs will further illustrate the signal processing performed by processor 120.

It should be noted that the processor 120 can also directly receive the input audio signal (Rt, Lt) or directly output the audio signal (Rout, Lout). Therefore, in some embodiments of the present invention, the audio signal playing device 100 does not need to include the specific audio signal input circuit 110 and/or the audio signal output circuit 130. In addition, according to other embodiments of the present invention, the processor 120 may also be configured only on one of the two-channel headphones, and the sensor 140 may be wired or wirelessly The information of the detected angle θ or the change of the angle θ is transmitted to the processor 120.

Figure 3 is a flow chart showing a method of processing an audio signal according to an embodiment of the present invention. First, a set of input audio signals ( R _t , L _t ) is received (step S302), wherein the input audio signal may include a left channel audio signal L _t and a right channel audio signal R _t . Then, the sensor detects the change angle Δθ _{L between} one of the left sound channels and one of the listener's receiving planes, and detects one of the right sound planes and the listener. The amount of change Δθ _R of the angle or angle of one of the planes is received (step S304). Next, the input left and right channel audio signals are converted into a plurality of multi-channel audio signals (step S306). For example, the processor 120 can convert the input left and right channel audio signals into five-channel audio signals, including the center signal X _C , the left signal X _L , the right signal X _R , the left rear signal X _{RL ,} and the right rear side. Signal X _RR .

Next, the processor 120 calculates a complex weight gain based on the information of the angle (step S308). Next, the processor 120 synthesizes a new multi-channel audio signal according to the obtained weight gain and the multi-channel audio signal (step S308). For example, the synthesized multi-channel audio signal may include center signals Y _CL and Y _CR , left signal Y _L , right signal Y _R , left rear signal Y _{RL ,} and right rear signal Y _RR . Finally, the processor 120 converts the synthesized multi-channel audio signal into a set of output audio signals ( R _out , L _out ) (step S310).

It is worth noting that the conversion method of converting two-channel audio signals into multi-channel (for example, 5-channel, 7-channel, etc.) audio signals and converting from multi-channel audio signals to two-channel can be Many different embodiments are well known in the art and, therefore, are not described in detail herein.

Figure 4 is a graph showing the relationship between the included angle and the included angle of a multi-channel audio signal according to an embodiment of the present invention. In this embodiment, the processor 120 can convert the input left and right channel audio signals ( R _t , L _t ) into a three-channel audio signal of the stereo space, including the center signal X _C at 0° and the center signal X. the _C angle is θ X _L, the angle between the left signal _L and the center signal _C X-X _RL of the left rear is a right side signal X _R θ _R signal, the angle between the center _C of the X-signal is θ _RL, and the center signal X _C is the angle θ _RR of the right rear signal X _RR. In Fig. 4, the position of one of the equivalent sound sources simulated by each audio signal is directly indicated by the corresponding audio signals X _C , X _L , X _R , X _RL and X _RR . For example, since the input left and right channel audio signals ( R _t , L _t ) can be converted into five-channel audio signals, based on this conversion, the input left and right channel audio signals ( R _t , L _t ) can be simulated Five equivalent sound sources, wherein the positions of the equivalent sound sources are represented by corresponding audio signals X _C , X _L , X _R , X _RL and X _RR in the figure to represent the sounds perceived by the listener The sound of the track is incident on the listener from the corresponding equivalent sound source position by the azimuth angles 0°, θ _L , θ _R , θ _RL , θ _RR indicated in the figure.

It is assumed that the amount of change between the angle of one of the left channel of the audio signal playback device 100 and the receiving plane of one of the left ear of the listener is Δθ _L , and the sound plane of one of the right channels of the audio signal playback device 100 The change in the angle of the receiving plane of one of the right ears of the listener is Δθ _R , and the change of the angle causes a change in the position of the equivalent sound source simulated by the input audio signal ( R _t , L _t ), wherein The positions of the changed equivalent sound sources are represented by corresponding audio signals Y _CL , Y _CR , Y _L , Y _R , Y _{RL ,} and Y _RR , respectively, in the figure. Since the equivalent sound source simulated by the input audio signal ( R _t , L _t ) changes position due to the angle change, the sound source perceived by the listener is incorrectly positioned, or the sound heard is distorted. Therefore, to correct for this offset, the processor 120 calculates a complex weight gain based on the angle information and synthesizes a new multi-channel audio signal from the multi-channel audio signal based on the resulting weight gain.

According to an embodiment of the invention, the processor 120 determines the amount of change Δθ _R /Δθ _L between the angle of the speaker plane and the receiving plane of the listener, and the equivalent sound source according to the sensor 140. The ratio of the angles is used to calculate the offset weight corresponding to each multi-channel audio signal, and the weight gain is calculated according to the offset weight, wherein the angles θ _L , θ _R , θ _RL , θ _RR between the equivalent sound sources are processed. The device 120 is known.

According to an embodiment of the present invention, the processor 120 can calculate the offset weights of the right signal, the left signal, the right rear signal, and the left rear signal according to the following formulas (1) to (4), respectively. :

And according to the following (5) to (12), according to the offset weight, the weight gain g corresponding to each multi-channel audio signal is calculated:

Then, the processor 120 can synthesize a new multi-channel audio signal according to the following formulas (13)-(18), wherein the Y _CR is a center signal at 0° synthesized by using the original center signal and the right signal, Y _CL In order to utilize another center signal at 0° synthesized by using the original center signal and the left signal, Y _L is the left side signal of the synthesis, Y _R is the right side signal of the synthesis, Y _RL is the left rear side signal of the synthesis, and Y _RR is Synthetic right rear side signal:

Finally, the processor 120 converts the synthesized multi-channel audio signal into a set of output audio signals ( R _out , L _out ) according to the following formulas (19) to (20): R _out = k ₀ . Y _CR + k ₁ . Y _R + k ₂ . Y _RR type (19)

L _out = k ₀ . Y _CL + k ₁ . Y _L + k ₂ . Y _RL type (20)

Where the coefficients k ₀ =0.707, k ₁ =1, k ₂ =0.707. The resulting output audio signal ( R _out , L _out ) can effectively compensate or correct the positional change or offset of one of the at least one equivalent sound source simulated by the input audio signal due to the angle change or offset.

It should be noted that the above formulas (1) to (20) are only one of many possible embodiments for implementing the present invention, and therefore, the present invention is not limited to the above calculation manner. For example, in the embodiment of the general earphone, since the variation of the angle between the sound plane of the left ear and the right ear and the receiving plane of the listener is independent, in the above calculation manner, the audio signals of the left and right ears are It is calculated independently. However, in the embodiment of the virtual reality wearing device, the amount of change in the angle between the sound plane of the left ear and the right ear and the receiving plane of the listener is related, and therefore must be different from the above (1) to (20). ) way of calculation.

As described above, the audio signal playing device and the corresponding audio signal processing method provided by the present invention can effectively overcome the angle change between the receiving plane of the listener and the sound plane of the earphone or the audio playback device, so that the listener feels The sound source is positioned incorrectly, or the sound heard is distorted to achieve a more realistic stereo sound design.

The above-described embodiments of the present invention can be performed in a variety of ways, such as using hardware, software, or a combination thereof. Those skilled in the art will appreciate that any component or combination of components that perform the functions described above can be considered as one or more processors that control the functions described above. The one or more processors can be executed in a variety of manners, such as by specifying hardware, or general purpose hardware programmed using microcode or software.

Although the present invention has been disclosed above in the preferred embodiment, it is not The scope of the present invention is defined by the scope of the appended claims, which is defined by the scope of the appended claims. quasi.

Claims (10)

An audio signal playing device includes: an inductor for detecting an angle between at least one sound plane of the audio signal playing device and a reference plane; and a processor coupled to the sensor for receiving A set of input audio signals, and receiving the information of the included angle, and processing the set of input audio signals according to the angle information to generate a set of output audio signals. The audio signal playing device of claim 1, wherein the set of input audio signals is a set of two-channel audio signals. The audio signal playing device of claim 1, wherein the set of output audio signals is a set of two-channel audio signals. The audio signal playing device of claim 1, wherein the processor continuously processes the set of input audio signals according to the information of the angle to compensate for at least the simulation of the set of input audio signals caused by the change of the angle A position change of one of the equivalent sound sources. The audio signal playing device of claim 1, wherein the processor further converts the set of input audio signals into a plurality of multi-channel audio signals, and calculates a complex weight gain according to the information of the angle, and according to the plurality of The channel audio signals and the weight gains produce the set of output audio signals. An audio signal processing method includes: receiving a set of input audio signals; detecting an angle between at least one sound plane of a sound signal playing device and a reference plane; and processing the set of input audio signals according to the information of the angles, Generate a set of losses And outputting an audio signal for compensating for a change in position of at least one equivalent sound source simulated by the set of input audio signals due to the included angle. The method of claim 6, further comprising: continuously detecting the change of the included angle; and processing the set of input audio signals according to the change of the included angle to compensate for the input audio signal caused by the change of the included angle The position of the at least one equivalent sound source that is simulated changes. The method of claim 6, wherein the step of processing the set of input audio signals according to the change of the included angle comprises: converting the set of input audio signals into a plurality of multi-channel audio signals; calculating according to the information of the included angle Complex weight gain; and generating the set of output audio signals based on the multi-channel audio signals and the weight gains. The method of claim 6, wherein the set of input audio signals is a set of two-channel audio signals. The method of claim 6, wherein the set of output audio signals is a set of two-channel audio signals.