Method and control circuit for synchronizing playback of multiple electronic devices

Abstract

A method and control circuit for synchronizing playing of a plurality of electronic devices, including a master device and a slave device, are provided. The method includes receiving audio data from a remote device by the master device as master-end audio data, and transmitting the master-end audio data to the slave device as slave-end audio data, wherein the slave device generates ultrasonic data in accordance with the slave-end audio data, so that the slave device plays the slave-end audio data and the ultrasonic data; estimating, by a correction circuit, a delay amount of the ultrasonic data received by a microphone of the master device relative to the master-end audio data; and controlling, by a delay circuit, a delay of the master-end audio data in accordance with the delay amount, to generate master-end output audio data for playing by the master device.

Description

Technical Field

[0001] This invention relates to playback synchronization, and more particularly to a method and control circuit for synchronizing playback from multiple electronic devices. Background Technology

[0002] During a conference call, multiple participants may be in the same conference room, each using their own devices (such as laptops) to run the conference call software. When these devices play audio simultaneously without sharing a single speakerphone, interference can occur. For example, when a far-end participant speaks and transmits their voice message to various laptops in the conference room via the conference call software, the timing of their audio playback can differ due to internet connectivity or laptop system limitations. In some cases, the playback time difference between different laptops can be as high as several seconds, causing the audio to stagger and resulting in poor clarity.

[0003] Therefore, a novel method and related control circuit are needed to solve the problem of multiple devices in the same environment simultaneously playing audio content from the same source but at different times. Summary of the Invention

[0004] The purpose of this invention is to provide a method and control circuit for synchronizing playback from multiple electronic devices, so as to solve the problems of related technologies without or with relatively little side effect.

[0005] At least one embodiment of the present invention provides a method for synchronizing playback of multiple electronic devices. The method may include: receiving audio data from a remote device other than the multiple electronic devices using a master device among the multiple electronic devices as master audio data, and transmitting the master audio data to at least one slave device among the multiple electronic devices as slave audio data, wherein the at least one slave device generates ultrasonic data based on the slave audio data, causing a speaker of the at least one slave device to play the slave audio data and the ultrasonic data; receiving the ultrasonic data using a microphone of the master device; estimating the delay of the ultrasonic data received by the microphone of the master device relative to the master audio data using a correction circuit of the master device; and controlling the delay of the master audio data based on the delay using a delay circuit of the master device to generate master output audio data for playback by the speaker of the master device.

[0006] At least one embodiment of the present invention provides a control circuit for synchronizing playback of multiple electronic devices, wherein the multiple electronic devices may include a master device and at least one slave device, and the master device may include the control circuit. The control circuit may include a correction circuit and a delay circuit, wherein the delay circuit is coupled to the correction circuit. Specifically, the correction circuit may be used to utilize audio data received by the network receiver of the master device as master audio data, and to estimate the delay of the ultrasonic data relative to the master audio data based on the master audio data and ultrasonic data received by the microphone of the master device. The at least one slave device may receive the master audio data from the master device as slave audio data, and generate the ultrasonic data based on the slave audio data, so that the speaker of the at least one slave device plays the slave audio data and the ultrasonic data. Additionally, the delay circuit may be used to control the delay of the master audio data based on the delay amount, to generate master output audio data for playback by the speaker of the master device.

[0007] At least one embodiment of the present invention provides a control circuit for synchronizing playback of multiple electronic devices, wherein the multiple electronic devices may include a master device and a slave device, and the slave device may include the control circuit. The control circuit may include an upsampling circuit, wherein the upsampling circuit can be used to upsampling slave-end audio data to generate ultrasonic data. For example, the slave device may receive master-end audio data as slave-end audio data, and the control circuit may transmit the slave-end audio data and the ultrasonic data to the speaker of the slave device for playback. Furthermore, after the microphone of the master device receives the ultrasonic data, the master device may estimate the delay of the ultrasonic data received by the microphone relative to the master-end audio data, and control the delay of the master-end audio data according to the delay amount to generate master-end output audio data for playback by the speaker of the master device.

[0008] The method and control circuit provided in the embodiments of the present invention can estimate the playback delay differences of various electronic devices by transmitting and detecting ultrasonic waves, and then compensate accordingly. Through the above mechanism, the playback of various electronic devices can tend to be synchronized, and the embodiments of the present invention do not significantly increase additional costs. Therefore, the present invention can solve the problems of related technologies without or with minimal side effects.

[0009] The features, operation, and effects of the present invention will be described in detail below with reference to the accompanying drawings, specifically the preferred embodiments. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating multiple electronic devices conducting a teleconference in the same environment according to an embodiment of the present invention.

[0011] Figure 2 This is a schematic diagram of multiple electronic devices conducting a teleconference in the same environment according to another embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram illustrating the synchronization of playback from multiple electronic devices according to an embodiment of the present invention.

[0013] Figure 4 This is a schematic diagram of an electronic device that can selectively function as either a master device or a slave device according to an embodiment of the present invention.

[0014] Figure 5 This is a schematic diagram of the spectrum of audio data according to an embodiment of the present invention.

[0015] Figure 6 This is a schematic diagram of the spectrum of audio data played by a speaker of a first slave device according to an embodiment of the present invention.

[0016] Figure 7 This is a schematic diagram of the spectrum of audio data played by the speaker of a second slave device according to an embodiment of the present invention.

[0017] Figure 8 This is a schematic diagram of the spectrum of audio data played by the speaker of a third slave device according to an embodiment of the present invention.

[0018] Figure 9 This is a workflow of a method for synchronizing playback of multiple electronic devices according to an embodiment of the present invention.

[0019] Figure 10 for Figure 9 Examples of the methods shown.

[0020] Symbol Explanation 10: Remote User Equipment 100, 200, 300, 400: User equipment 110, 210, 410: Audio control chips 111, 411: Frequency upscaling circuit 212, 412: Correction circuit 213, 413: Frequency reduction circuit 214, 414: Delay circuits 120, 220, 420: Network receiver 130, 230, 430: Speakers 240, 440: Microphone 12: Data transmission interface VM0, VM1, VM2, VM3, VM4, VM5: Audio data BB1, BB2, BB3: Audio data UB1, UB2, UB3: Ultrasonic data S910~S940, S110~S170: Steps Detailed Implementation

[0021] Figure 1 This is a schematic diagram illustrating multiple electronic devices, such as user devices 100, 200, and 300, conducting a telephone conference in the same environment according to an embodiment of the present invention. In this embodiment, multiple users can respectively use user devices 100, 200, and 300 to conduct telephone conferences with remote users (e.g., users using remote user device 10) outside the same conference room, wherein remote user device 10 and user devices 100, 200, and 300 can be desktop computers, laptops, smartphones, or any electronic device capable of running telephone conferencing software. Figure 1 As shown, after a remote user's voice message is transmitted to the Internet via remote user device 10, user devices 100, 200, and 300 can use their respective network interfaces (e.g., their respective wired / wireless network interfaces) to retrieve the voice message from remote user device 10 via the Internet, and then play it themselves. For ease of understanding, Figure 1 The different types of dashed lines represent the configurations where user devices 100, 200, and 300 each acquire and play audio data independently. However, since user devices 100, 200, and 300 may be products from different manufacturers, their wired / wireless network interfaces, related processing circuits, and playback devices may have different specifications and performance. Therefore, in the configuration where user devices 100, 200, and 300 acquire and play audio data independently, although they play the same audio content, the playback timing between devices may be inconsistent.

[0022] Figure 2 This is a schematic diagram illustrating user devices 100, 200, and 300 conducting a teleconference in the same environment according to another embodiment of the present invention. In this embodiment, user device 200 can act as a master device, while other devices such as user devices 100 and 300 act as slave devices. Compared to Figure 1In this embodiment, in addition to playing the audio data obtained from the Internet, user device 200 also transmits the audio data to user devices 100 and 300. Although user devices 100 and 300 can still obtain audio data from remote user devices via the Internet, they play the audio data received from user device 200 instead of the audio data obtained from the Internet. This solves the problem caused by differences in network latency, such as wired / wireless network interfaces. Furthermore, to further reduce playback latency differences caused by internal system differences among user devices 100, 200, and 300, each of user devices 100, 200, and 300 may include corresponding control circuitry to synchronize playback.

[0023] Figure 3 This is a schematic diagram illustrating the synchronization of playback on user devices 100 and 200 according to an embodiment of the present invention. In this embodiment, user device 100 can act as a slave device and user device 200 can act as a master device. Figure 3 As shown, user device 100 may include an audio control chip 110, a network receiver 120, and a speaker, while user device 200 may include an audio control chip 210, a network receiver 220, a speaker 230, and a microphone 240. User device 100 and user device 200 can be interconnected via data transmission interface 12. It should be noted that... Figure 3 The data transmission interface 12 shown is for illustrative purposes only and is not intended to limit the invention. For example, the data transmission interface 12 may be a physical cable. Alternatively, the data transmission interface 12 may be implemented via a wired or wireless local area network. The detailed implementation of the data transmission interface 12 can vary as long as the user device 200 can transmit data to the user device 100 via the data transmission interface 12.

[0024] In this embodiment, the network receiver 220 of user device 200 can receive audio data from remote user device 10 via the Internet as master audio data VM0. User device 200 can then transmit the master audio data VM0 to user device 100 via data transmission interface 12 as slave audio data VM1. It should be noted that although the network receiver 120 of user device 100 can also obtain audio data from remote user device 10, the audio control chip 110 can directly discard the audio data obtained from the network receiver 120. In this embodiment, user device 100 can generate ultrasonic data VM2 based on the slave audio data VM1, so that speaker 130 plays the slave audio data VM1 and ultrasonic data VM2. For example, the audio data VM3 played by speaker 130 may include the slave audio data VM1 and ultrasonic data VM2. Specifically, the audio control chip 110 may include an upsampling circuit 111, which can be used to upsample the slave audio data VM1 to generate ultrasonic data VM2. It should be noted that both the master audio data VM0 and the slave audio data VM1 are within the listening frequency range (e.g., the frequency band between 20 Hz and 20,000 Hz), and the ultrasonic data is within the ultrasonic frequency band (e.g., the frequency band above 20,000 Hz).

[0025] After the microphone 240 of the user device 200 receives audio data VM3 (especially ultrasonic data VM2 therein), the user device 200 can estimate the delay of the audio data VM3 (e.g., the ultrasonic data VM2 therein) received by the microphone 240 relative to the master audio data VM0, and control the delay of the master audio data VM0 according to the delay to generate master output audio data VM5 for playback by the speaker 230 of the user device 200. In this embodiment, the audio control chip 210 of the user device 200 may include a correction circuit 212, a down-conversion circuit 213, and a delay circuit 214, wherein the correction circuit 212 is coupled to the down-conversion circuit 213, and the delay circuit 214 is coupled to the correction circuit 212. In this embodiment, the down-conversion circuit 213 can be used to down-convert the ultrasonic data VM2 in the audio data VM3 received by the microphone 240 to generate fundamental frequency data VM4, wherein the fundamental frequency data VM4 is within the listening frequency range. The correction circuit 212 can estimate the delay of the ultrasonic data VM2 (or the slave audio data VM1 in the audio data VM3) relative to the master audio data VM0 based on the master audio data VM0 and the ultrasonic data VM2 in the audio data VM3 received by the microphone 240. In particular, it can compare the baseband data VM4 with the master audio data VM0 to estimate the delay. In addition, the delay circuit 214 can control the delay of the master audio data VM0 based on the delay to generate master output audio data VM5 for playback by the speaker 230. For example, the delay circuit 214 can apply the delay to the master audio data VM0 to generate master output audio data VM5, so that the slave audio data VM1 in the audio data VM3 played by the speaker 130 is synchronized with the master output audio data VM5 played by the speaker 230.

[0026] Figure 3 The embodiment uses user devices 100 and 200 as examples, and the synchronous operation between user devices 100 and 300 can be deduced similarly. Furthermore, Figure 3 In this embodiment, user device 200 is used as the master device and user device 100 (or user device 300) is used as the slave device. Therefore, the audio control chip 210 of user device 200, which acts as the master device, and the audio control chip 110 of user device 100, which acts as the slave device, may have different architectures. However, this is only for illustrative purposes and is not a limitation of the invention. For example, user devices 100, 200, and 300 may have audio control chips with the same architecture, wherein any one of user devices 100, 200, and 300 can act as the master device, and each of the others can act as the slave device.

[0027] Figure 4This is a schematic diagram of a user device 400 that can selectively function as either the master device or the slave device according to an embodiment of the present invention, wherein the user device 400 may be an example of any (e.g., each) of a plurality of electronic devices such as user devices 100, 200, and 300 in the same environment. Figure 4 As shown, the user device 400 may include an audio control chip 410, a network receiver 420, a speaker 430, and a microphone 440, wherein the operation of the network receiver 420, the speaker 430, and the microphone 440 is related to... Figure 3 The network receivers 120 and 220, speakers 130 and 230, and microphone 240 operate similarly in the embodiments, and will not be repeated here for the sake of simplicity. In this embodiment, the audio control chip 410 may include an up-conversion circuit 411, a correction circuit 412, an down-conversion circuit 413, and a delay circuit 414. When the user device 400 acts as the master device, the user device 400 can transmit the audio data (e.g., audio received by the network receiver 420) to the network receiver 420. Figure 3 In this embodiment, the master audio data VM0 is transmitted to one or more user devices acting as the slave device, and the microphone 440 receives the audio data played by the one or more user devices (e.g., audio data VM0) Figure 3 After processing the ultrasonic data VM2 in the audio data VM3 of the embodiment, the audio control chip 410 can use the correction circuit 412, the down-conversion circuit 413, and the delay circuit 414 to perform delay estimation and compensation, so that the audio data played by the speaker 430 can be synchronized with the audio data played by one or more user devices. Details regarding the correction circuit 412, the down-conversion circuit 413, and the delay circuit 414 are as follows... Figure 3 The correction circuit 212, down-conversion circuit 213, and delay circuit 214 in the embodiments are similar and will not be repeated here for the sake of simplicity. When the user device 400 acts as the slave device, the user device 400 can discard the audio data received by the network receiver 420 and receive audio data from the user device acting as the master device (e.g., Figure 3 In the embodiment of VM1), the audio control chip 410 can use the upsampling circuit 411 to perform correlation processing on the audio data from the main device before controlling the speaker 430 to play the processed audio data (e.g., Figure 3 The embodiment uses audio data VM3 to allow the microphone of the main device to receive audio data played by the speaker 430 for delay estimation and compensation. Details of the upsampling circuit 411 are related to... Figure 3 The upsampling circuit 111 in the embodiment is similar, and will not be repeated here for the sake of simplicity.

[0028] exist Figure 3 The embodiment described uses the synchronization of two electronic devices as an example, but the invention is not limited thereto. Figure 2As shown, when user device 200 acts as the master device, the user devices acting as the slave devices may include user device 100 and user device 300. In this case, user device 100 and user device 300 may act as the first slave device and the second slave device, respectively, wherein user device 100 may receive master audio data (e.g., audio data from user device 200) from user device 200. Figure 3 The master audio data VM0 shown is used as the first slave audio data, and the user device 300 can receive the master audio data from the user device 200 as the second slave audio data.

[0029] Figure 5 This is a schematic diagram of the spectrum of audio data according to an embodiment of the present invention, wherein... Figure 5 The audio data shown can be an example of any (e.g., each) of the master audio data of user device 200, the first slave audio data of user device 100, and the second slave audio data of user device 300. Specifically, user device 100 can generate first ultrasonic data, such as..., based on a first portion of the first slave audio data (e.g., audio data BB1 located in a first frequency band). Figure 6 The ultrasonic data UB1 shown is used to cause the speaker of user device 100 to play ultrasonic data UB1 within the ultrasonic frequency band and the first slave audio data within the listening frequency range. Additionally, user device 300 can generate second ultrasonic data based on a second portion of the second slave audio data (such as audio data BB2 located in the second frequency band). Figure 7 The ultrasonic data UB2 shown is used to cause the speaker of user device 300 to play ultrasonic data UB2 within the ultrasonic frequency band and the second slave audio data within the listening frequency range. Specifically, the first frequency band may be different from the second frequency band, wherein user device 100 generates ultrasonic data UB1 by up-converting audio data BB1, and user device 300 generates ultrasonic data UB2 by up-converting audio data BB2. The microphone of user device 200 receives the audio data played by the speaker of user device 100 (such as...) Figure 6 After receiving the ultrasonic data UB1 and the first slave audio data shown, the user device 200 can use its internal correction circuit 212 to estimate the first delay of the ultrasonic data UB1 received by the microphone of the user device 200 (e.g., the fundamental frequency data generated after the ultrasonic data UB1 is down-frequencyd by the down-frequency circuit 213) relative to the audio data BB1 in the master audio data. Additionally, after the microphone of the user device 200 receives the audio data played by the speaker of the user device 300 (e.g., the first slave audio data), the user device 200 can use its internal correction circuit 212 to estimate the first delay of the ultrasonic data UB1 received by the microphone of the user device 200 (e.g., the fundamental frequency data generated after the ultrasonic data UB1 is down-frequencyd by the down-frequency circuit 213) relative to the audio data BB1 in the master audio data. Figure 7After receiving the ultrasonic data UB2 and the second slave audio data, the user device 200 can use its internal correction circuit 212 to estimate a second delay amount of the ultrasonic data UB2 received by the user device 200's microphone (e.g., the fundamental frequency data generated after the ultrasonic data UB2 is down-frequencyd by the down-frequency circuit 213) relative to the audio data BB2 in the master audio data. Therefore, the user device 200 can determine the amount of delay that needs to be applied to the master audio data based on the first delay amount and the second delay amount.

[0030] When the first delay is greater than the second delay, the user device 200 can set the delay amount to be applied to the master audio data to the first delay, so that the audio data played by the speaker of the user device 200 can be synchronized with the audio data played by the speaker of the user device 100. Additionally, the correction circuit 212 of the user device 200 can calculate the delay difference between the first delay and the second delay, and apply the delay difference to the second slave audio data to generate slave output audio data for playback by the speaker of the user device 300. For example, the user device 200 can apply the delay difference to the master audio data to generate delayed audio data, and then transmit this delayed audio data to the user device 300. Alternatively, the user device 200 can transmit the master audio data and a signal carrying the delay difference information together to the user device 300, allowing the user device 300 to apply the delay difference to the second slave audio data to generate delayed audio data for playback by the speaker of the user device 300. In other words, the present invention can identify the slave device with the most severe delay among multiple slave devices, and align the playback time of the audio data of the master device and the remaining slave devices with the slave device with the most severe delay, thereby achieving a synchronization effect.

[0031] Furthermore, if either the first delay or the second delay exceeds a threshold, user device 200 can mute the slave device in user device 100 and user device 300 corresponding to that delay. For example, when the first delay exceeds the threshold but the second delay does not, user device 200 can send a mute request to user device 100 to mute user device 100, wherein user device 200 can set the delay amount to be applied to the master audio data as the second delay amount, so that the audio content played by user device 200 can be synchronized with the audio content played by user device 300. As another example, when both the first delay and the second delay exceed the threshold, user device 200 can send a mute request to each of user devices 100 and 300 to mute both user devices 100 and 300.

[0032] Furthermore, if there are three or more slave devices, the operation can be similarly described. For example, a third slave device can generate third ultrasonic data based on a third portion of the audio data (such as audio data BB3 located in a third frequency band). Figure 8 The ultrasonic data UB3 shown is for playback. Those skilled in the art should be able to understand from the above description how to estimate the delay of the third slave device based on the ultrasonic data UB3; for the sake of simplicity, this will not be repeated here. It should be noted that since the audio data BB1, BB2, and BB3 can be data from different frequency bands (e.g., the first, second, and third frequency bands), the user device acting as the master device can determine which slave device's playback delay the currently estimated delay belongs to based on the frequency band of the currently received ultrasonic data (or its down-frequency result).

[0033] Figure 9 This is a workflow of a method for synchronizing playback on multiple electronic devices according to an embodiment of the present invention, wherein user devices 100, 200, and 300 may be examples of the multiple electronic devices. It should be noted that one or more steps may be performed... Figure 9 The workflow shown has been added, deleted, or modified. Furthermore, these steps do not necessarily need to be followed exactly as long as they do not affect the overall result. Figure 9 Execute in the order shown.

[0034] In step S910, the main device among the plurality of electronic devices (e.g., Figure 2 The user device 200 shown can receive audio data from a remote device other than the plurality of electronic devices as master audio data, and transmit the master audio data to at least one slave device among the plurality of electronic devices (e.g., Figure 2 The user device 100 or 300 shown can be used as slave audio data, wherein the at least one slave device can generate ultrasonic data based on the slave audio data so that the speaker of the at least one slave device can play the slave audio data and the ultrasonic data.

[0035] In step S920, the main device can receive the ultrasonic data using its microphone.

[0036] In step S930, the master device can use its correction circuit to estimate the delay of the ultrasonic data received by the microphone of the master device relative to the master audio data.

[0037] In step S940, the main device can use its delay circuit to control the delay of the main audio data according to the delay amount, so as to generate main output audio data for the main device's speaker to play.

[0038] Figure 10 for Figure 9The examples of the methods shown include one or more steps that can be performed at any time. Figure 10 The workflow shown has been added, deleted, or modified. Furthermore, these steps do not necessarily need to be followed exactly as long as they do not affect the overall result. Figure 10 Execute in the order shown.

[0039] In step S110, the main device (e.g.) Figure 2 The user device 200 shown can transmit audio data (e.g., the aforementioned master audio data) to the slave device (e.g., Figure 2 (either of the user devices 100 and 300 shown).

[0040] In step S120, the slave device can receive the audio data as slave-end audio data.

[0041] In step S130, the slave device can upsample the data of a specific frequency band in the slave audio data into ultrasonic data.

[0042] In step S140, the slave device can play the ultrasonic data and the slave audio data through its speaker.

[0043] In step S150, the master device can receive the ultrasonic data and the slave audio data through its microphone.

[0044] In step S160, the master device can compare the ultrasonic data with its own audio data (e.g., the master audio data mentioned above) to estimate the delay.

[0045] In step S170, the main device can adjust the playback delay of its own audio data according to the delay amount.

[0046] In summary, the method and control circuit provided by the embodiments of the present invention transmit data loaded with ultrasonic waves from the slave devices, allowing the master device to estimate the playback delay of the slave devices after receiving the ultrasonic waves via a microphone. Therefore, after estimating the playback delay of the slave devices, the master device can perform corresponding compensation for itself or each slave device, so that the playback of multiple electronic devices in the same environment can tend to be synchronized. Furthermore, the embodiments of the present invention do not significantly increase additional costs. Therefore, the present invention can solve the problems of related technologies without or with minimal side effects.

[0047] Although preferred and feasible embodiments of the present invention have been disclosed above, these embodiments are not intended to limit the present invention. Those skilled in the art can make changes to the technical features of the present invention based on the explicit or implicit content of the present invention. All such changes fall within the scope of patent protection sought by the present invention. In other words, the scope of patent protection of the present invention shall be determined by the scope defined in the claims of this application.

Claims

1. A method for synchronizing playback from multiple electronic devices, characterized in that, The method includes: The master device among the plurality of electronic devices receives audio data from a remote device other than the plurality of electronic devices as master audio data, and transmits the master audio data to a plurality of slave devices among the plurality of electronic devices as slave audio data. Each of the plurality of slave devices up-frequency a corresponding portion of the slave-end audio data to generate corresponding ultrasonic data, so that the speakers of the plurality of slave devices respectively play the corresponding slave-end audio data and the corresponding ultrasonic data. The main device uses its microphone to receive the ultrasonic data played by the multiple slave devices. The master device's calibration circuit is used to estimate the delay of each ultrasonic data received by the microphone of the master device from each slave device relative to the master device's audio data; and The delay circuit of the master device controls the delay of the master audio data according to the maximum delay among the delay values, so as to generate master output audio data for playback by the speaker of the master device, wherein the playback of the master device is synchronized with the playback of the slave device corresponding to the maximum delay among the plurality of slave devices.

2. The method as described in claim 1, characterized in that, Estimating the delay of the ultrasonic data received by the microphone of the main device relative to the main audio data using the correction circuit of the main device includes: The ultrasonic data received by the microphone of the main device is down-frequencyd using the down-frequency circuit of the main device to generate fundamental frequency data; and The correction circuit is used to compare the baseband data with the master audio data to estimate the delay.

3. The method as described in claim 1, characterized in that, A first slave device among the plurality of slave devices receives master-end audio data from the master device as first slave-end audio data, and a second slave device among the plurality of slave devices receives master-end audio data from the master device as second slave-end audio data. The first slave device generates first ultrasonic data based on a first portion of the first slave-end audio data, causing the first slave device to play the first ultrasonic data and the first slave-end audio data. The second slave device generates second ultrasonic data based on a second portion of the second slave-end audio data, causing the second slave device to play the second ultrasonic data and the second slave-end audio data. The first portion of the first slave-end audio data corresponds to a first portion of the master-end audio data, and the second portion of the second slave-end audio data corresponds to a second portion of the master-end audio data. Estimating the delay of the ultrasonic data received by the microphone of the master device relative to the master-end audio data using the correction circuit includes: The correction circuit is used to estimate the first delay of the first ultrasonic data received by the microphone of the main device relative to the main audio data; The correction circuit is used to estimate the second delay of the second ultrasonic data received by the microphone of the main device relative to the main audio data; and The delay amount is determined based on the first delay amount and the second delay amount.

4. The method as described in claim 3, characterized in that, Determining the delay amount based on the first delay amount and the second delay amount includes: Since the first delay amount is greater than the second delay amount, the delay amount is set to the first delay amount.

5. The method as described in claim 3, characterized in that, The method further includes: Since the first delay is greater than the second delay, the correction circuit calculates the delay difference between the first delay and the second delay, and applies the delay difference to the second slave audio data to generate slave output audio data for playback by the speaker of the second slave device.

6. The method as described in claim 3, characterized in that, The method further includes: If either the first delay amount or the second delay amount exceeds a threshold, the slave device corresponding to either the first slave device or the second slave device is set to mute.

7. The method as described in claim 1, characterized in that, The master audio data and the slave audio data are within the listening frequency range, and the ultrasonic data is within the ultrasonic frequency band.

8. A control circuit for synchronizing playback from multiple electronic devices, characterized in that, The plurality of electronic devices includes a master device and a plurality of slave devices, the master device including the control circuit, the control circuit including: A correction circuit is configured to use audio data received by the network receiver of the master device as master audio data, and to estimate the delay of each ultrasonic data point relative to the master audio data based on the master audio data and multiple ultrasonic data points received by the microphone of the master device, wherein each of the plurality of slave devices receives the master audio data from the master device as slave audio data, and upsamples a corresponding portion of the slave audio data to generate corresponding ultrasonic data, so that the speakers of the plurality of slave devices respectively play the corresponding slave audio data and the corresponding ultrasonic data; and A delay circuit, coupled to the correction circuit, is used to control the delay of the master audio data based on the maximum delay among the delay values, so as to generate master output audio data for playback by the speaker of the master device.

9. A control circuit for synchronizing playback from multiple electronic devices, characterized in that, The plurality of electronic devices includes a master device and a slave device, the slave device including the control circuit, the control circuit including: An upsampling circuit is used to upsampling the slave audio data to generate ultrasonic data, wherein the slave device receives master audio data from the master device as the slave audio data, and the control circuit transmits the slave audio data and the ultrasonic data to the speaker of the slave device for playback. After the microphone of the main device receives the ultrasonic data, the main device estimates the delay of the ultrasonic data received by the microphone relative to the main audio data, and controls the delay of the main audio data according to the delay to generate main output audio data for playback by the speaker of the main device. The master device determines the delay amount based on the maximum delay amount among the delay amounts of the multiple slave devices, so that the playback of the master device is synchronized with the playback of the slave device corresponding to the maximum delay amount.

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