Audio Conferencing System with Separate Microphone Array
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Solution Overview
Problem
Conventional all-in-one displays face challenges in providing high-quality audio conferencing due to the use of single omnidirectional microphones and independent audio subsystems, leading to low signal-to-noise ratios and acoustic echo issues, especially in multi-participant settings.
Innovation Solution
The system includes a separate microphone assembly with multiple microphones and a processor that performs echo cancellation using remote audio as a reference, allowing for selective mixing and routing of audio signals to improve audio quality and reduce echo.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single omnidirectional microphone is used to pick up audio in the local room, then the device complexity is reduced and ease of manufacture is improved, but the signal-to-noise ratio deteriorates due to picking up significant noise from directions other than the talker
Solution Approach 1:
The single omnidirectional microphone is segmented into multiple directional microphones arranged in an array. Each microphone captures audio from a specific direction, allowing the system to selectively combine signals to achieve both simplicity and high signal-to-noise ratio.
Solution Approach 2:
Different microphones in the array are positioned to capture audio from different local directions. The system applies local quality by weighting and combining signals from specific microphones based on the talker's direction, improving signal-to-noise ratio while maintaining ease of manufacture through a modular array design.
2Adaptability or versatility
If an omnidirectional microphone is placed in the middle of a conference table, then the ease of operation is improved and adaptability is enhanced, but acoustic echo increases due to picking up reflected speech energy from various surfaces
Solution Approach 1:
The harmful reflected speech energy is extracted and identified as a separate component from the direct path speech. The echo cancellation system separates the echo signal from the desired speech signal, allowing for selective removal of the harmful reflected energy while preserving the direct speech.
Solution Approach 2:
The system converts the harmful acoustic echo into a beneficial feature by using the omnidirectional nature of the microphone array to capture reflected energy that can be used for echo estimation. This estimated echo is then subtracted from the total signal, transforming the previously harmful reflection into a useful component for improving speech quality.
3Measurement precision
If a microphone array is used in the bezel of the display, then the signal-to-noise ratio is improved for speech from local participants, but the device complexity increases and manufacturing becomes more difficult
Solution Approach 1:
The microphone array in the display bezel serves multiple functions: it provides high signal-to-noise ratio for speech capture, enables acoustic echo cancellation, and supports spatial audio processing. This multi-functionality justifies the increased device complexity by delivering superior performance across multiple audio processing tasks.
Solution Approach 2:
The microphone array functionality is merged with the display bezel structure, combining audio capture capabilities with the visual display framework. This integration reduces overall system complexity by consolidating components and simplifies manufacturing through unified design and assembly processes.
4Adaptability or versatility
If independent audio subsystems are used in the PC and display controller, then the adaptability is improved and ease of operation is enhanced, but acoustic echo cancellation becomes difficult due to independent volume controls
Solution Approach 1:
The system implements feedback by routing the audio output from the display controller back to the audio input of the PC subsystem. This feedback loop enables the echo cancellation algorithm to monitor and compensate for acoustic echo in real-time, maintaining reliable echo cancellation despite independent volume controls in the dual audio subsystem architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the signal-to-noise ratio and reduces echo, resulting in high-quality audio conferencing on commodity PC hardware, comparable to dedicated systems, with improved intelligibility and reduced noise.
Implementation Method 1
a processor that performs echo cancellation using remote audio as a reference
Data Source
AI summary
A conferencing system may comprise an electronic display configured to display remote video generated within a remote conference room, a speaker configured to reproduce remote audio generated within the remote conference room, and a processor configured to receive local audio generated within a local conference room and picked up by a microphone assembly that is part of a separate device from the electronic display. A related method may include displaying remote video on an electronic display of an all-in-one display, reproducing remote audio through at least one speaker of the all-in-one display; and performing echo cancellation of local audio using the remote audio as an echo cancellation reference. Another method may include receiving, at an all-in-one display, a plurality of local audio signals from a plurality of microphone assemblies that are separate from the all-in-one display, and controlling, within the all-in-one display, gating of the plurality of microphone assemblies.