Virtual Microphone ICA for Separating More Sources Than Sensors

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Solution Overview

Problem

Existing independent component analysis (ICA) methods are limited in separating sound source signals from a number of sound sources greater than the number of microphones, leading to increased costs due to the need for an equal or greater number of microphones.

Innovation Solution

A sound source separation system using a set of omnidirectional microphones and a virtual microphone signal generator to create virtual unidirectional microphones with different directivities, combined with an ICA processor to separate sound source signals, allowing for a greater number of sound sources to be separated than the number of microphones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of microphones is increased to separate more sound sources, then the separation capability is improved, but the hardware cost and system complexity increase

Engineering Contradiction:

Improveseparation capabilityVSAvoidhardware cost

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates virtual unidirectional microphones by processing signals from omnidirectional microphones. These virtual microphones are copies of what real unidirectional microphones would produce, allowing the system to achieve directional separation capabilities without physically installing directional microphones for each sound source direction.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent transforms the problem from spatial dimension (adding more physical microphones in different positions) to signal processing dimension (creating virtual microphones through mathematical operations). By generating m > n virtual microphone signals from n physical microphones, the system effectively adds dimensions to the signal space without adding physical hardware.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the number of microphones equals or exceeds the number of sound sources, then separation accuracy is improved, but the system becomes less adaptable to varying numbers of sound sources

Engineering Contradiction:

Improveseparation accuracyVSAvoidflexibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent creates a dynamic system where the number of virtual microphones m can be flexibly configured independently of the fixed number of physical microphones n. This allows the system to adapt to different numbers of sound sources L by adjusting m, while maintaining separation accuracy through the ICA method applied to the virtual microphone signals.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20260004797A1Sound source separation system

Publication Date: 2026.01.01 ALPS ALPINE CO LTD

AI summary

A sound source separation system is configured to perform blind source separation of individual sound source signals by an independent component analysis (ICA) method from a plurality of mixed signals in which two or more sound source signals are mixed. The sound source separation system includes an n number of microphones, where n≥2; a virtual microphone signal generator configured to generate, from output signals of the n number of the microphones, an m number of the virtual microphone signals that are output signals of the m number of virtual unidirectional microphones having directivities in different directions, where m>n; and an ICA processor configured to separate an L number of the sound source signals that are signals of the L number of different sound sources, by the ICA method, from the m number of the virtual microphone signals that are the plurality of the mixed signals, where L>n and L≤m.