Microphone Gain Adjustment Using Distance Sensing
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Solution Overview
Problem
Existing audio signal level regulators fail to maintain a constant audio level regardless of the distance to a talker and do not effectively reflect changes in the talker's volume.
Innovation Solution
A gain adjustment device comprising a level adjuster, a sensor, and a setter that measures physical quantities varying with distance, such as time difference or signal level ratios, to adjust the audio signal gain accordingly, ensuring a constant level and reflecting volume changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional automatic level regulator is used to monitor and attenuate high-level signals, then the signal level can be controlled, but the audio level cannot be maintained constant regardless of distance to talker and changes in talker volume are not effectively reflected
Solution Approach 1:
The patent employs feedback mechanisms where the sensor detects physical quantities (such as distance or acoustic characteristics) and feeds this information back to the level adjuster, which then dynamically adjusts the gain to maintain constant audio level. This closed-loop feedback system enables the device to adapt to changing talker distances and volumes while maintaining reliable audio output.
Solution Approach 2:
The patent changes the operating parameters of the audio system by dynamically adjusting the gain based on sensor measurements. The level adjuster modifies audio signal parameters (amplitude/gain) in response to detected physical quantity changes, enabling the system to maintain constant audio level across varying talker distances and volumes.
2Measurement precision
If gain is adjusted based on signal level monitoring alone, then high-level signals can be attenuated, but the system cannot distinguish between distance changes and volume changes
Solution Approach 1:
The patent introduces a sensor as an intermediary device that measures physical quantities (such as distance or acoustic field characteristics) to provide additional information about the acoustic environment. This intermediary measurement enables the system to distinguish between distance changes and volume changes, preventing information loss while maintaining precise signal level detection.
Data Source
AI summary
A gain adjustment method includes using a sensor to measure a physical quantity that varies according to a distance, and adjusting a level of an audio signal obtained by a microphone according to a measurement result of the sensor.