Audio Automatic Mixer With Frequency-Weighted Microphone Selection
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Solution Overview
Problem
Conventional automatic mixers in audio capture systems often select microphones based on energy or signal level, leading to suboptimal audio signal generation when talkers are positioned away from the microphone, causing attenuation of voiced consonants due to high-frequency speech energy directivity.
Innovation Solution
An audio automatic mixer that separates high-frequency and low-frequency speech energy, determines energy levels, and selects a preferred audio signal based on weighted energy levels to improve audio signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional automatic mixer selects microphone based on energy or signal level, then the selection process is simple, but audio signal quality deteriorates when talker is positioned away from the selected microphone
Solution Approach 1:
The patent divides the audio frequency spectrum into multiple frequency bands (e.g., low-frequency, mid-frequency, high-frequency) and calculates energy levels separately for each band. This segmentation allows the system to evaluate microphone performance across different frequency ranges, particularly capturing high-frequency speech energy that indicates talker proximity and direction, thereby improving audio signal quality selection
Solution Approach 2:
The patent changes the selection parameter from simple total energy level to frequency-weighted energy level, specifically emphasizing high-frequency components. By weighting high-frequency energy more heavily, the system can identify microphones that are both close to and properly oriented toward the talker, resolving the issue of selecting microphones that capture loud but directionally incorrect speech
2Adaptability or versatility
If microphone is positioned at 90-degree angle to talker, then the physical arrangement is flexible, but voiced consonants are attenuated due to high-frequency speech energy directivity
Solution Approach 1:
The patent applies frequency weighting to the energy calculation, giving higher weight to high-frequency components that carry voiced consonant information. This allows the system to detect and compensate for directional attenuation effects, selecting microphones that maintain better high-frequency response even in flexible physical arrangements
Solution Approach 2:
The system continuously monitors the high-frequency energy levels from each microphone and uses this feedback to dynamically adjust microphone selection. When a microphone positioned at an angle shows reduced high-frequency energy, the feedback mechanism triggers selection of an alternative microphone with better high-frequency capture, maintaining voice clarity throughout the meeting
Data Source
AI summary
A method is provided that is performed at a system including multiple speech collectors to collect speech from a talker to produce corresponding ones of multiple audio signals that each convey speech energy: for each audio signal: separating high-frequency speech energy from low-frequency speech energy; and determining a first energy level of the high-frequency speech energy; and determining a preferred audio signal among the multiple audio signals for subsequent processing at least based on the first energy level of each audio signal.