Ceiling-Mounted Microphone Array Beamforming for Noise Exclusion
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Solution Overview
Problem
Existing microphone array systems for conference environments face challenges in providing enhanced participant freedom, effective speech acquisition, and reducing setup effort, while also dealing with noise interference and space constraints.
Innovation Solution
A ceiling-mounted microphone array system with a processing unit that steers a beam to enhance speech acquisition, reduces noise interference, and minimizes setup effort by using a direction recognition unit, delay units, and frequency response correction filters, along with a SRP-PHAT algorithm to identify audio sources and adjust beam direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If one microphone is installed for each participant, then speech acquisition quality is improved, but table space is restricted and setup effort increases
Solution Approach 1:
Multiple individual microphones are merged into a single ceiling-mounted microphone array system. The array comprises multiple microphone capsules arranged in a specific geometric pattern, combining their functions into one centralized device that eliminates the need for multiple separate microphones on the table.
Solution Approach 2:
The patent introduces a processing unit as an intermediary between the microphone capsules and the audio output. This processing unit implements beamforming algorithms to electronically direct audio capture, mediating the transition from physical microphone placement to virtual directional capture.
2Ease of operation
If one or more omnidirectional microphones are used, then table space is freed and participant mobility is improved, but noise interference increases and speech acquisition quality deteriorates
Solution Approach 1:
The microphone array system dynamically adjusts its beamforming parameters in real-time based on the detected positions of speakers and noise sources. The beam direction and shape are continuously adapted to track moving participants while excluding stationary noise sources, providing both mobility freedom and noise rejection.
Solution Approach 2:
The system employs feedback mechanisms where the processing unit continuously analyzes audio signals from all microphone capsules, identifies speaker and noise source positions, and adjusts beamforming parameters accordingly. This closed-loop control enables real-time adaptation to changing acoustic environments.
3Measurement precision
If head-mounted microphones are used for each participant, then speech acquisition quality is improved and table space is freed, but setup effort and complexity increase
Solution Approach 1:
The ceiling-mounted microphone array system provides self-service by automatically detecting speaker positions and adjusting beamforming parameters without requiring manual configuration for each participant. The system adapts to different meeting scenarios autonomously, eliminating the need for individual microphone setup.
Solution Approach 2:
The single ceiling-mounted array serves multiple functions that would otherwise require separate devices: it captures speech from multiple participants simultaneously, tracks moving speakers, rejects noise sources, and provides audio output without requiring individual microphones for each participant.
4Object-affected harmful factors
If beamforming is implemented to reduce noise, then noise interference is reduced, but computational power requirements increase
Solution Approach 1:
The system applies partial beamforming by focusing computational resources on the most critical directions - specifically toward detected speakers and away from identified noise sources. Rather than processing all possible directions equally, the system concentrates computational power where it provides maximum benefit.
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 enables participants to move freely with high-quality speech acquisition, reduces noise interference, and simplifies setup by automatically adjusting to audio sources, improving speech clarity and reducing computational power requirements.
Implementation Method 1
a plurality of microphone capsules arranged in or on the front board
Implementation Method 2
The microphone array system may comprise a processing unit that is configured to receive the output signals of the microphone capsules and to steer the beam based on the received output signal
Implementation Method 3
a SRP-PHAT algorithm to identify audio sources and adjust beam direction
Data Source
AI summary
A microphone array system or microphone array unit for a conference system is provided that includes a front board, side walls and a plurality of microphone capsules arranged in or on the front board mountable on or in a ceiling of a conference room. The microphone array system or unit is adapted for generating a steerable beam within a maximum detection angle range. The microphone array system or microphone array unit includes a processing unit which is configured to receive the output signals of the microphone capsules and to steer the beam based on the received output signal of the microphone array. The processing unit is configured to control the microphone array to limit the detection angle range to exclude at least one predetermined exclusion sector in which a noise source is located.