Wireless Audio Playback Coordination for Clock Drift Correction

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Solution Overview

Problem

Achieving high audio quality in an environment is challenging due to improper placement of acoustic sources and listener positioning, which can degrade acoustic quality and user satisfaction.

Innovation Solution

An audio/video (A/V) hub coordinates playback times of electronic devices using wireless communication to synchronize audio content, correcting for clock drift and adapting to acoustic characteristics and listener location.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If wireless communication is used to coordinate playback times, then ease of operation is improved, but measurement precision of time synchronization deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system continuously monitors the actual playback time at each electronic device and compares it with the expected playback time. Time offset values are calculated based on these comparisons and fed back to the A/V hub, which then adjusts the playback timing information sent to each device. This closed-loop feedback mechanism enables the system to compensate for wireless communication uncertainties and maintain precise time synchronization without requiring complex manual configuration.

Inventive Principle:
Principle #23Feedback

2Reliability

If clock drift correction is implemented, then reliability of audio synchronization is improved, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each electronic device autonomously determines its own time offset value by comparing its local clock with the synchronized time provided by the A/V hub. The devices self-correct their playback timing without requiring manual intervention or complex external synchronization equipment. The A/V hub simply distributes timing information and receives feedback, allowing each device to independently manage its own clock drift correction.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If acoustic characteristics and listener location are considered, then acoustic quality is improved, but measurement precision requirements increase

Engineering Contradiction:
Improveacoustic qualityVSAvoidmeasurement precision
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The system adjusts the playback timing information by modifying temporal parameters based on acoustic characteristics and listener location. The A/V hub calculates optimal playback times that account for acoustic delays, room acoustics, and listener position, then encodes these adjusted timing parameters in the playback information sent to electronic devices. This allows the system to optimize audio quality without requiring complex measurement infrastructure at each device.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4250747B1Wireless coordination of audio sources
Publication Date: 2026.04.08 B & W GRP LTD
  • EP4250747B1 patent drawingFigure 1
  • EP4250747B1 patent drawingFigure 2
  • EP4250747B1 patent drawingFigure 3

AI summary

An audio/video (A/V) hub that coordinates playback of audio content is described. In particular, the A/V hub may calculate current time offsets between clocks in electronic devices and a clock in the A/V hub based on differences between transmit times of frames from the electronic devices and receive times when the frames were received. For example, the current time offsets may be calculated using wireless ranging by ignoring distances between the A/V hub and the electronic devices. Then, the A/V hub may transmit, to the electronic devices, one or more frames that include audio content and playback timing information, which may specify playback times when the electronic devices are to playback the audio content based on the current time offsets. Furthermore, the playback times of the electronic devices may have a temporal relationship so that the playback of the audio content by the electronic devices is coordinated.