Wireless Earbud Latency Compensation via Feedback Synchronization

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Solution Overview

Problem

Wireless headsets with truly wireless communication between two earpieces introduce latency, causing a noticeable lag between audio and video playback, which needs to be compensated for to ensure synchronized media experience.

Innovation Solution

The system detects and compensates for latency by having a primary audio device transmit audio data to a second audio device, calculating an audio delay time based on acknowledgment signals, and synchronizing video playback on an electronic device with the audio delay time to align audio and video playback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If truly wireless communication is implemented between two earpieces, then wireless freedom and device independence are improved, but audio latency increases causing lag between audio and video playback

Engineering Contradiction:
Improvewireless freedomVSAvoidaudio latency
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by having the electronic device send video timing information to the first audio device before audio playback, and by pre-calculating the audio delay time based on acknowledgment signals. This allows the system to proactively compensate for the inherent wireless latency between earpieces by adjusting video playback timing in advance, thereby resolving the contradiction between wireless freedom and audio latency.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If audio data is transmitted wirelessly between primary and second audio devices, then device independence is improved, but synchronization accuracy deteriorates due to variable transmission delays

Engineering Contradiction:
Improvedevice independenceVSAvoidaudio-video synchronization accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system implements feedback by having the second audio device send an acknowledgment signal back to the primary audio device after receiving audio data. The primary audio device uses this feedback to calculate the actual audio delay time experienced in the wireless transmission. This closed-loop feedback mechanism allows the system to dynamically measure and compensate for variable transmission delays, thereby maintaining synchronization accuracy despite device independence.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The electronic device performs preliminary action by sending video timing information to the first audio device before playback, enabling the system to pre-adjust video timing based on expected audio delivery characteristics. This proactive timing adjustment works in conjunction with the feedback mechanism to maintain synchronization accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3759896B1Dynamic lip-sync compensation for truly wireless bluetooth devices
Publication Date: 2022.11.23 SONY GROUP CORP
  • EP3759896B1 patent drawingFigure 1
  • EP3759896B1 patent drawingFigure 2
  • EP3759896B1 patent drawingFigure 3

AI summary

Audio systems in which a primary audio device (28) communicates wirelessly with a second audio device (36) include a latency caused by the communication between the two audio devices. For example, a truly wireless audio device can comprise a first earpiece and a second earpiece. The electronic device (10) that is playing a media file transmits audio data to the first earpiece. The first earpiece then transmits a portion of the audio data to the second earpiece. This communication between the first and second earpiece causes a latency that the system can account for in order to synchronize a video playback with the corresponding audio playback on the wireless headset.