Array Microphone Beam Former for Talker Switching Latency

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Solution Overview

Problem

Existing array microphones that form a single sound collection beam often experience a time lag when switching between talkers, leading to missed beginnings of new utterances, and require excessive calculation to estimate multiple sound source directions and form corresponding beams.

Innovation Solution

An array microphone system with multiple microphones, an estimator to determine sound source directions, and a beam former that forms multiple sound collection beams, allowing for efficient tracking of multiple sound sources by directing additional beams beyond the estimated directions, reducing calculation by limiting estimated sound source directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single sound collection beam is formed and tracked to follow the sound source direction, then the direction tracking is accurate, but a time lag occurs when switching between talkers causing missed beginnings of new utterances

Engineering Contradiction:

Improvesound source direction tracking accuracyVSAvoidtime lag during talker switching

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system pre-forms multiple sound collection beams in advance at different directions before a talker switch occurs. When a new talker is detected, one of the pre-formed beams is already positioned to capture the new sound source immediately, eliminating the time lag associated with recalculating and re-forming a single tracking beam.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the number and distribution of sound collection beams based on the acoustic environment and detected sound sources. Instead of maintaining a fixed single beam, the system forms multiple beams with varying directions and gains, allowing flexible adaptation to talker switching scenarios while maintaining accurate direction tracking.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If multiple sound collection beams are formed to support multiple sound source directions, then talker switching is improved, but the computational load increases excessively

Engineering Contradiction:

Improvemulti-directional sound collection capabilityVSAvoidcalculation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of uniformly distributing computational resources across all possible directions, the system applies different qualities and densities of sound collection beams to different spatial regions. High-priority regions with detected or likely sound sources receive focused beams with higher gain, while other regions receive fewer or lower-priority beams, optimizing the balance between multi-directional capability and computational load.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes parameters such as the number of beams, beam directions, and beam gains based on the acoustic scene and processing requirements. By dynamically adjusting these parameters rather than maintaining a fixed large number of beams, the system achieves versatile multi-directional sound collection while controlling computational complexity through adaptive parameter optimization.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11297419B2Array microphone and sound collection method

Publication Date: 2022.04.05 YAMAHA CORP

AI summary

A sound collection method and a microphone array estimate at least one sound source direction and form a plurality of sound collection beams in the estimated plurality of sound source direction, using sound collection signals of a plurality of microphones. The number of sound source directions estimated is smaller than the number of sound collection beams formed.