Beamforming Microphone Area Segmentation for Lower Processing Load
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Solution Overview
Problem
Existing beamforming microphone systems face high processing loads due to continuous sound source search and directivity calculation, and lack flexibility in setting sound pickup areas, leading to instability and signal adjustment challenges.
Innovation Solution
A beamforming microphone system with a signal processing unit that identifies sound source positions within individually set sound pickup areas, generates sound signals for these areas, and assigns output channels based on predefined area positions, reducing processing load and enhancing flexibility in sound pickup area settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the beamforming microphone repeatedly performs sound source search and directivity calculation at all times, then the sound source position can be accurately identified and directivity can be directed to the sound source, but the processing load becomes large causing operational instability and thermal runaway
Solution Approach 1:
The sound pickup area is divided into multiple individual sound pickup areas, each associated with a specific output channel. The system performs directivity calculation and sound source search only within these segmented areas rather than the entire sound pickup area, reducing the processing load while maintaining accurate sound source identification within each segment.
Solution Approach 2:
Instead of performing complete sound source search and directivity calculation across the entire sound pickup area at all times, the system performs partial action by limiting the search and calculation to only those individual sound pickup areas where sound sources are actually present, reducing unnecessary processing while maintaining effectiveness.
2Productivity
If the sound signal from the beamforming microphone is output via 1ch output channel to reduce calculation load, then the processing load is reduced, but it becomes difficult to adjust signals according to sound source switching and volume differences
Solution Approach 1:
The system divides the sound pickup area into multiple individual sound pickup areas, each mapped to a separate output channel. This segmentation allows different signal processing and adjustment operations to be applied to each channel independently, enabling flexible signal adjustment for different sound sources while maintaining reduced processing load compared to handling the entire area as one channel.
Solution Approach 2:
Each individual sound pickup area and its associated output channel is designed to be universally applicable for different sound sources. The system can dynamically assign different sound sources to different channels based on their positions, providing multi-functional capability for handling various speaking persons with different volumes and positions through the same segmented channel structure.
3Productivity
If the beamforming microphone picks up sound from a speaker in the same room, then the speaker sound is captured, but howling occurs due to feedback recognition
Solution Approach 1:
The system extracts and excludes the speaker area from the individual sound pickup areas where sound source search and directivity calculation are performed. By removing the harmful feedback path from the active sound pickup zones, the system maintains complete pickup of useful sound sources while eliminating the howling feedback caused by speaker recognition.
4Object-affected harmful factors
If an excluded sector is set using polar angle and azimuth angle to exclude noise sources, then the excluded sector range can be set in specific directions, but the position and shape of the excluded sector are restricted and flexible setting for individual sound pickup area cannot be implemented
Solution Approach 1:
The system segments the sound pickup area into multiple individual sound pickup areas that can be independently configured. This segmentation allows flexible setting of both excluded sectors for noise reduction and included areas for sound pickup, enabling adaptive configuration that neither fixed polar/azimuth sectors nor complete area coverage can provide.
Data Source
AI summary
A beamforming microphone system capable of reducing a processing load caused by calculation of directivity and flexibly setting an area where sound is picked up. A beamforming microphone system according to the present invention includes: a plurality of microphone units; a signal processing unit that processes a sound pickup signal from each microphone unit at each predetermined time; and a storage that associates, for each sound pickup area, sound pickup area information with individual-sound-pickup-area position information freely set within the sound pickup area and stores the information. The signal processing unit includes a position information identification unit that identifies sound source position information, a signal generation unit that generates the sound signal corresponding to the sound from the sound source position, and a channel assignment unit that assigns an output channel, based on the individual-sound-pickup-area position information on the individual sound pickup area to which the sound source position belongs.