Multi-Microphone Gain Control for Stable Volume Switching
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Solution Overview
Problem
Conventional sound pickup systems experience volume differences when switching between microphones due to differing gain settings, leading to sudden volume changes and potential difficulty in hearing speakers with lower gain microphones.
Innovation Solution
A sound pickup device with multiple microphones and processors implementing first and second gain controlling tasks, where each microphone has a gain controller (AGC) that adjusts gain based on input levels and shares a consistent gain setting value across all microphones, ensuring consistent volume output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If each microphone has independent gain control (AGC), then each microphone can adjust gain based on its input levels, but volume differences occur when switching between microphones
Solution Approach 1:
The patent implements a universal gain setting mechanism where a single gain value determined by the second AGC is applied to all microphones through the first AGCs. This ensures that all microphones operate with consistent gain settings, eliminating volume differences during switching while maintaining the adaptability of individual AGC control.
2Measurement precision
If selection switches to a microphone with large gain, then the microphone can capture sound better, but volume becomes large suddenly
Solution Approach 1:
The patent employs a feedback mechanism where the second AGC continuously monitors the overall sound level and adjusts the gain setting that is applied to all microphones. This feedback loop ensures that when switching between microphones, the gain remains consistent with the current sound environment, preventing sudden volume changes while maintaining optimal sound capture.
3Object-affected harmful factors
If gain is decreased for unexpected noise, then noise level is reduced, but sound at the beginning of talk becomes difficult to be heard
Solution Approach 1:
The patent implements dynamic gain control where the second AGC continuously adjusts the gain setting based on real-time sound level monitoring. This dynamic adjustment allows the system to maintain appropriate gain levels for speech detection at the beginning of talks while reducing gain during periods of unexpected noise, ensuring both speech detectability and noise reduction are achieved through adaptive control.
Data Source
AI summary
A sound pickup device includes a plurality of microphones, and at least one processor configured to implement stored instructions and execute a plurality of tasks, including: a first gain controlling task controlling a gain of each of the plurality of microphones, an adding task adding a sound signal to be output from the first gain controlling task with a predetermined gain, a second gain controlling task controlling a gain of the sound signal to be output from the adding task; and a gain setting task setting each gain of the first gain controlling task based on gain setting in the second gain controlling task.