Adaptive Sound Collection with Variable Filter Update Speed
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Solution Overview
Problem
Existing sound collecting devices struggle to improve voice signal quality in noisy environments, as they often fail to effectively differentiate between voice signals generated by microphones and vibration sensors, leading to inclusion of environmental noise.
Innovation Solution
A sound collecting device equipped with a microphone, vibration sensor, adaptive filter, and controller that adjusts filter coefficients based on voice presence to minimize residual signals, updating coefficients faster during voice sections and slower or not at all during non-voice sections to maintain sound quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the adaptive filter continuously updates the coefficient to minimize the residual signal, then the voice signal quality improves, but environmental noise is included in the voice signal
Solution Approach 1:
The patent applies dynamics by making the filter coefficient update speed variable rather than constant. The adaptive controller adjusts the update speed based on whether voice is detected: updating quickly during voice sections to improve quality, and updating slowly or pausing during non-voice sections to avoid capturing environmental noise. This dynamic adjustment resolves the contradiction between improving voice quality and avoiding noise inclusion.
Solution Approach 2:
The patent changes the parameter of filter coefficient update speed based on voice presence detection. By detecting whether voice is present and adjusting the update speed parameter accordingly, the system optimizes the balance between voice signal quality improvement and environmental noise rejection. This parameter change allows the system to adapt to different acoustic conditions.
2Speed
If the filter coefficient is updated quickly to improve voice signal quality, then the response to voice changes is faster, but the system may capture environmental noise
Solution Approach 1:
The system dynamically adjusts the coefficient update speed based on voice presence. During voice sections, the update speed is increased to quickly adapt to changing voice characteristics. During non-voice sections, the update speed is reduced or paused to prevent capturing environmental noise. This dynamic speed adjustment resolves the contradiction between fast response and noise rejection.
Solution Approach 2:
The patent uses feedback from voice presence detection to control the filter coefficient update process. The adaptive controller continuously monitors whether voice is present and uses this feedback to adjust the update speed accordingly. This feedback mechanism ensures that fast updates occur only when beneficial (during voice sections) and slow updates or pauses occur when noise rejection is prioritized (during non-voice sections).
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
The device enhances voice signal quality by adaptively controlling filter coefficients, reducing environmental noise interference and maintaining sound quality without frequent updates, thus improving the output in noisy conditions.
Implementation Method 1
a microphone configured to generate a first voice signal based on air vibration
Implementation Method 2
a vibration sensor configured to generate a vibration signal based on vibration transmitted to a human body by speech
Data Source
AI summary
A microphone generates a voice signal based on air vibration. A vibration sensor generates a vibration signal based on vibration transmitted to a human body. An adaptive filter multiplies the vibration signal by a coefficient to generate a converted voice signal. A subtractor generates a residual signal that is a difference between the voice signal and the converted voice signal. The adaptive controller controls the adaptive filter to update the coefficient so that the residual signal becomes small at a first speed when it is determined to be a voice section, and controls the adaptive filter to update the coefficient so that the residual signal becomes small at a second speed slower than the first speed when it is determined to be a non-audio section, or supplies the adaptive filter control signal to the adaptive filter to control not to update the coefficient.