Circular Microphone Array Layout for 360° Speech Pickup
Find Innovative SolutionsGenerate Solutions
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.
Innovation Solution
A microphone device with a vertical center axis and 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 circumference, and varying spacing to enhance sensitivity in horizontal directions and attenuate vertical noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single microphone is arranged on the cylinder axis, then the device structure is simple, but the possibilities for conference-specific audio processing are limited
Solution Approach 1:
The patent divides the single microphone into multiple microphones arranged in an array around the central axis. This segmentation allows the system to capture sound from different directions simultaneously, enabling advanced audio processing techniques such as beamforming and directional filtering that were not possible with a single microphone.
Solution Approach 2:
The patent transitions from a one-dimensional single microphone on the axis to a two-dimensional array of microphones distributed around the axis. This dimensional expansion provides spatial information about sound sources, enabling the system to process audio with directional awareness and enhance conference-specific applications.
2Ease of manufacture
If the spacing distance between external surface parts is uniform, then the manufacturing is simpler, but the sound directionality and noise attenuation are less effective
Solution Approach 1:
The patent applies different spacing distances between the first and second external surface parts at different locations around the housing. This local variation in spacing creates specific acoustic paths that enhance directionality and noise attenuation in particular directions, optimizing the microphone's performance for conference room environments where speakers are typically positioned at certain angles.
3Area of stationary object
If microphones are arranged close to the outer circumference, then the sound reception area is maximized, but the sensitivity to horizontal sounds is reduced due to reflections
Solution Approach 1:
The patent positions microphones at a specific radial distance from the outer circumference (at least 25% of the distance from the circumference toward the center). This intermediate positioning in the radial dimension optimizes the balance between having enough reception area and minimizing table reflections, while still maintaining good sensitivity to horizontal sounds from speakers around the conference table.
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 design provides improved sound reception and amplification in horizontal directions, reducing noise interference and enabling effective post-processing for directionality and speech enhancement.
Implementation Method 1
an open sound reception cavity extends 360 degrees around the vertical centre axis from an outer circumference towards the centre axis
Data Source
Figure 1~2
Figure 3~6
Figure 7~10
AI summary
A microphone device (1) having a housing comprising a first external surface part (2a) and a second external surface part (2b) opposing said first external surface part (2a) so that an open sound reception cavity (7) extends 360 degrees around a vertical centre axis (A-A) from an outer circumference (6a, 6b) towards the centre axis (A-A). A microphone array comprising at least two microphones (4a, 4h) are arranged in the cavity (7) with the microphones (4a- 4h) distributed on a circle (3) with the centre axis (A-A) as centre. The microphones (4a, 4h) are arranged at least 25% of the distance between the outer circumference (6a, 6b) and the vertical centre axis (A-A) from the outer circumference (6a, 6b).