Microphone With Movable Sound Delay Filter for Noise Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microphones, particularly directional MEMS microphones, face challenges in noisy environments like vehicle interiors, where they struggle with sensitivity and frequency response, and require high audio performance, reliability, and operability.
Innovation Solution
The method involves manufacturing a microphone with sound delay filters and thermal actuators that can switch between directional and non-directional modes based on noise levels, using carbon nanotubes and metal pads for efficient sound aperture management, allowing the microphone to adapt its sensitivity and frequency response to environmental noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a directional MEMS microphone is used to capture sounds only in desired directions, then noise rejection is improved, but sensitivity and frequency response characteristic deteriorate
Solution Approach 1:
The patent implements a movable sound delay filter that can dynamically change its position between two states: a first position for directional operation and a second position for non-directional operation. This dynamic reconfiguration allows the microphone to adapt its directional characteristics in real-time, switching between noise rejection mode and sensitivity mode based on environmental conditions.
Solution Approach 2:
The patent changes the physical position parameter of the sound delay filter to alter the acoustic path length. By adjusting the position of the sound delay filter relative to the sound sensing module, the system modifies the acoustic parameters (delay time, phase) to achieve different operational modes: directional with noise rejection or non-directional with high sensitivity.
2Object-affected harmful factors
If a directional microphone is used to function against surrounding noise, then noise rejection is improved, but frequency response characteristic deteriorates
Solution Approach 1:
The movable sound delay filter enables dynamic switching between directional and non-directional modes. When high frequency response is needed, the filter moves to the second position to enable non-directional operation, capturing full frequency spectrum without the frequency response degradation inherent in fixed directional microphones.
3Measurement precision
If a non-directional microphone is used, then sensitivity is improved, but noise rejection deteriorates
Solution Approach 1:
The system dynamically switches between operational modes by moving the sound delay filter. When high sensitivity is required, the filter moves to the second position for non-directional operation. When noise rejection becomes priority, the filter moves to the first position for directional operation, thus resolving the contradiction between sensitivity and noise rejection.
4Adaptability or versatility
If a movable sound delay filter is implemented to switch between directional and non-directional modes, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical moving parts with thermal actuators that use thermal expansion/contraction to move the sound delay filter. This substitution reduces mechanical complexity while achieving the same positional switching function, thereby improving adaptability without proportionally increasing device complexity.
Solution Approach 2:
The thermal actuators utilize thermal expansion and contraction of materials to achieve linear motion of the sound delay filter. By heating or cooling the actuator material, the system can move the filter between positions without requiring motors, gears, or other complex mechanical actuation systems.
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
This approach enables the microphone to maintain low power consumption and reduce manufacturing costs while effectively handling variable noise environments by selectively switching between directional and non-directional modes, improving sensitivity and frequency response.
Implementation Method 1
forming thermal actuators disposed at both sides of the first sound delay filter and moving the first sound delay filter in accordance with whether power is supplied
Implementation Method 2
forming thermal actuators disposed at both sides of the first sound delay filter and moving the first sound delay filter in accordance with whether power is supplied
Data Source
AI summary
A method of manufacturing a microphone, a microphone, and a method of controlling the microphone are provided. The method includes forming a sound sensing module on a mainboard having a first sound aperture, to be connected with the first sound aperature and forming a cover having a second sound aperature that corresponds to the first sound aperature, mounted on the mainboard, and housing the sound sensing module. A first and second sound delay filters are formed in a space defined by the cover, to be connected with the second sound hole and thermal actuators are disposed at both sides of the first sound delay filter and move the first sound delay filter based on whether power is supplied. A semiconductor chip is electrically connected with the sound sensing module in the space and selectively operates the thermal actuators in response to signals from the sound sensing module.