Microphone System Shock Noise Cancellation
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Solution Overview
Problem
Condenser microphones experience degradation in output signals due to mechanical shocks, causing noise and vibration in the diaphragm, which affects the quality of the audio signal.
Innovation Solution
A microphone system comprising a primary microphone and a correction microphone, both mechanically coupled to receive identical shock signals, with combining logic that uses the correction microphone's output to remove noise components from the primary microphone's signal, including the use of low pass filters and adaptive filters to mitigate low-frequency audio components and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single microphone is used to capture audio signals, then the device complexity is low, but the signal-to-noise ratio degrades under mechanical shock
Solution Approach 1:
The single microphone is segmented into two functional components: a primary microphone for capturing audio signals and a secondary microphone for capturing shock signals. This segmentation allows the system to separately process audio and noise components, improving the signal-to-noise ratio by enabling noise cancellation through signal subtraction.
Solution Approach 2:
A secondary microphone is introduced as an intermediary device that captures mechanical shock signals. This intermediary provides noise reference data that is processed through combining logic to subtract noise components from the primary microphone output, thereby improving audio quality without directly modifying the primary audio capture path.
2Reliability
If mechanical shock protection is added to the microphone, then the reliability under shock improves, but the device complexity increases
Solution Approach 1:
Instead of adding mechanical shock protection structures to the microphone, the patent substitutes a electronic solution using a secondary microphone and signal processing. The secondary microphone captures mechanical shock signals, and combining logic electronically subtracts the corresponding noise from the primary microphone output, replacing mechanical protection with an electronic compensation approach.
Solution Approach 2:
The secondary microphone acts as an intermediary that measures mechanical shock effects without interfering with the primary audio capture. Its output is processed through combining logic to generate a noise cancellation signal, providing mechanical shock protection through electronic means rather than physical modification of the primary microphone.
3Measurement precision
If noise cancellation processing is implemented, then the audio quality improves, but the processing complexity increases
Solution Approach 1:
The system implements feedback by using the secondary microphone's shock signal output as input to the combining logic, which then generates a noise cancellation signal fed back to subtract from the primary microphone output. This feedback loop continuously compensates for noise based on real-time shock measurements, improving audio quality through adaptive noise cancellation.
Solution Approach 2:
The combining logic extracts the noise component from the primary microphone signal by subtracting the processed secondary microphone signal. This extraction isolates and removes the harmful noise portion while preserving the desired audio content, improving measurement precision through selective signal removal.
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 caused by mechanical shocks, enhancing the quality of the output audio signal.
Implementation Method 1
the second microphone apparatus is capable of producing a second output signal having a mechanical response that is substantially identical to the mechanical response of the first microphone apparatus
Implementation Method 2
the second microphone apparatus has a microphone and a low pass filter
Implementation Method 3
The combining logic uses the second output signal to remove at least a portion of the noise component from the first output signal
Data Source
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 first microphone apparatus may have a first back-side cavity and the second microphone may have a second back-side cavity. The first and second back-side cavities may be fluidly unconnected. 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.