Microphone System Mitigating Mechanical Shock Noise

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Solution Overview

Problem

Condenser microphones experience degradation in output signal due to mechanical shocks, causing vibrations that affect the microphone's performance.

Innovation Solution

A microphone system comprising a primary microphone and a correction microphone, both receiving identical mechanical signals, with combining logic that uses the correction microphone's output to remove noise components from the primary microphone's signal, enhancing the quality of the audio output by mitigating the effects of mechanical shocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single microphone is used to capture audio signals, then the device complexity is low, but the signal quality deteriorates under mechanical shock due to diaphragm vibration

Engineering Contradiction:
Improvesignal qualityVSAvoidmicrophone system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system divides the audio capture function into two separate microphone apparatuses: a first microphone for capturing audio signals and a second microphone for capturing mechanical shock signals. This segmentation allows each microphone to be optimized for its specific function, with the second microphone exclusively tracking mechanical vibrations that affect the first microphone's diaphragm.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces combining logic as an intermediary component that processes signals from both microphones. This logic analyzes the mechanical shock signals from the second microphone and uses them to compensate for vibration-induced noise in the first microphone's output, effectively mediating between the raw audio signal and the final processed output.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the diaphragm is exposed to acoustic waves for signal capture, then audio signal detection is effective, but mechanical shocks cause unwanted vibrations that degrade output

Engineering Contradiction:
Improveaudio signal detectionVSAvoidmechanical shock impact
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system implements feedback by using the second microphone to continuously monitor mechanical shock signals and feeding this information back through the combining logic to the first microphone's output. The combining logic uses this feedback to dynamically adjust and compensate for vibration-induced noise, creating a closed-loop system that actively counteracts mechanical shock effects.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent converts the harmful mechanical vibrations into a useful signal by using the second microphone to capture the same mechanical shocks that affect the first microphone. These captured vibration signals are then processed and used to cancel out the unwanted noise in the audio output, transforming the harmful vibration into a corrective element.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If both microphones are exposed to identical mechanical signals, then noise cancellation is effective, but the system complexity increases with additional components

Engineering Contradiction:
Improvenoise removal effectivenessVSAvoidmicrophone apparatus quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of audio capture and mechanical shock monitoring into a single integrated system. Both microphone apparatuses are positioned to experience identical mechanical signals, and their outputs are combined through the combining logic to produce a single corrected audio signal, effectively merging two functions into one cohesive system.

Inventive Principle:
Principle #5Merging (Combining)

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 system significantly improves the signal-to-noise ratio by effectively removing noise components, resulting in a cleaner audio signal with reduced interference from mechanical shocks.

Implementation Method 1

a correction microphone coupled to the same base to both receive the same noise signals... The second microphone apparatus may have a microphone and a low pass filter

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

Condenser microphones typically have a diaphragm that forms a capacitor with an underlying backplate. Receipt of an audible signal causes the diaphragm to vibrate to form a variable capacitance signal representing the audible signal.

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 3

the second microphone apparatus has a microphone and a low pass filter

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Data Source

PatentEP1917836B1Noise mitigating microphone system and method
Publication Date: 2012.07.25 ANALOG DEVICES INC
  • EP1917836B1 patent drawingFigure 1
  • EP1917836B1 patent drawingFigure 2
  • EP1917836B1 patent drawingFigure 3A~3B

AI summary

A microphone system has a base coupled with first and second microphone apparatuses. The first microphone apparatus is capable of producing a first output signal having a noise component, while the second microphone apparatus is capable of producing a second output signal. The system also has combining logic operatively coupled with the first microphone apparatus and the second microphone apparatus. The combining logic uses the second output signal to remove at least a portion of the noise component from the first output signal.