360-Degree Microphone Array Cavity for Vertical Noise Suppression
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Solution Overview
Problem
Existing microphone devices for conference rooms face challenges in achieving uniform sensitivity in all 360-degree horizontal directions while suppressing noise from vertical directions, such as ceiling fans and ventilation, and require advanced audio processing to enhance speech clarity.
Innovation Solution
A microphone device with a housing comprising two opposing external surface parts forming a 360-degree sound reception cavity, featuring a microphone array with microphones distributed at least 25% from the center axis, and varying spacing to enhance sensitivity in horizontal directions and attenuate vertical noise, allowing for post-processing to achieve directionality and amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single microphone is arranged on the cylinder axis with a tall cylindrical body, then the microphone device can achieve uniform sensitivity in all 360-degree horizontal directions, but the device complexity increases and the microphone array cannot provide advanced audio processing capabilities
Solution Approach 1:
The housing is divided into first and second external surface parts that are separated by a spacing distance, creating a sound reception cavity. This segmentation allows the microphone array to be positioned within the cavity while maintaining 360-degree horizontal sensitivity through the geometric arrangement of the housing parts.
Solution Approach 2:
The microphones are arranged in three-dimensional space within the sound reception cavity rather than being confined to a single plane. The microphones are distributed on a circle with the centre axis as centre, positioned at least 25% of the distance from the outer circumference towards the centre axis, enabling both 360-degree horizontal coverage and vertical noise suppression.
2Area of stationary object
If the microphones are arranged close to the outer circumference of the housing, then the sound reception area is maximized, but the sensitivity to vertical noise from ceiling fans and ventilation increases
Solution Approach 1:
The housing is designed with different properties at different locations: the first and second external surface parts are separated by a spacing distance that creates a sound reception cavity, while the microphones are positioned at specific radial distances from the centre axis. This local differentiation allows the housing to provide 360-degree horizontal reception while the microphone positioning attenuates vertical noise.
Solution Approach 2:
The sound reception cavity acts as an intermediary structure between the external environment and the microphone array. The cavity, formed by the spacing between housing parts, allows horizontal sound waves to reach the microphones while blocking vertical noise sources from the ceiling.
3Measurement precision
If a high cylinder is used with a single microphone, then the microphone device can achieve uniform sensitivity, but the device cannot provide advanced audio processing for enhancing speech from specific persons
Solution Approach 1:
The housing is segmented into multiple parts with a spacing distance creating a cavity, which allows for a microphone array configuration. This segmentation enables both uniform sensitivity through the geometric arrangement and advanced audio processing through the multiple microphone elements that can be processed to achieve directionality in all 360 degrees.
Solution Approach 2:
The patent combines multiple microphones into a single integrated array within the sound reception cavity, merging their signals to achieve both uniform sensitivity and advanced audio processing capabilities. The microphone array can be processed to dynamically achieve directionality while maintaining 360-degree horizontal coverage.
4Volume of moving object
If the spacing distance between housing parts is reduced, then the device size is minimized, but the attenuation of vertical noise is reduced
Solution Approach 1:
The spacing distance between the first and second external surface parts is optimized to provide the necessary sound reception cavity volume for vertical noise attenuation while keeping the overall device size acceptable. The spacing is sufficient to create the cavity needed for noise suppression but does not excessively increase the device dimensions.
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 provides improved sound reception and amplification in horizontal directions, suppressing vertical noise, and enables effective audio processing for enhanced speech clarity and reduced noise interference.
Implementation Method 1
an open sound reception cavity extends 360 degrees around the vertical centre axis from an outer circumference towards the centre axis
Implementation Method 2
a microphone array comprising at least two microphones arranged in the cavity
Data Source
AI summary
A microphone device having a housing comprising a first external surface part and a second external surface part opposing said first external surface part so that an open sound reception cavity extends 360 degrees around a vertical centre axis from an outer circumference towards the centre axis. A microphone array comprising at least two microphones are arranged in the cavity with the microphones distributed on a circle with the centre axis as centre. The microphones are arranged at least 25% of the distance between the outer circumference and the vertical centre axis from the outer circumference.