Acoustic Transfer Function Personalization via Virtual Array Beamforming

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Solution Overview

Problem

Determining acoustic transfer functions for microphone arrays is a lengthy and resource-intensive process, as it requires direct evaluation and is unique to each array configuration, making it challenging to accurately analyze sound scenes and generate surround sound experiences.

Innovation Solution

A wearable device with an audio system dynamically updates acoustic transfer functions by detecting sound sources, estimating their direction of arrival, tracking movement, and isolating signals, using confidence levels to refine these functions and improve sound filtering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct evaluation is used to determine acoustic transfer functions for each microphone array, then accuracy is improved, but time consumption and resource requirements increase significantly

Engineering Contradiction:

Improveaccuracy of acoustic transfer functionsVSAvoidtime consumption for determination

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates virtual microphone arrays by copying the spatial sampling pattern of the physical array. Virtual arrays are generated at different positions and orientations through signal processing, eliminating the need for physical relocation and direct evaluation at each position. This allows the system to obtain acoustic transfer functions for multiple positions without additional measurement time.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system performs preliminary calibration by measuring acoustic transfer functions at a reference position once, then uses signal processing techniques to compute transfer functions for other positions. This preliminary action at a single position enables subsequent rapid determination of transfer functions throughout the operational area without repeated direct measurements.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If direct evaluation is used to determine acoustic transfer functions for each microphone array configuration, then accuracy is improved, but resource requirements and complexity increase

Engineering Contradiction:

Improveaccuracy of acoustic transfer functionsVSAvoidcomplexity of determination process

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical approach of physically moving and reconfiguring microphone arrays with signal processing operations. Instead of mechanically relocating arrays to different positions for direct evaluation, the system uses mathematical transformations on signals from a single fixed array to compute transfer functions for virtual positions, significantly reducing mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system develops a universal signal processing framework that can determine acoustic transfer functions for any position and orientation within the operational area using the same physical array configuration. This multi-functional approach allows a single array setup to serve multiple measurement positions that would otherwise require separate physical arrays or repeated physical reconfigurations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If acoustic transfer functions are determined for multiple source locations and positions, then sound scene analysis accuracy is improved, but the process becomes more resource-intensive

Engineering Contradiction:

Improvesound scene analysis accuracyVSAvoidcomputational resources required

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements continuous tracking of sound sources and dynamic updating of acoustic transfer functions as sources move within the operational area. Instead of performing discrete, resource-intensive re-measurements, the system continuously processes incoming audio signals to update transfer function estimates, maintaining high accuracy while distributing computational load over time rather than concentrating it in intensive batch operations.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS11361744B2Acoustic transfer function personalization using sound scene analysis and beamforming

Publication Date: 2022.06.14 META PLATFORMS TECHNOLOGIES LLC

AI summary

An audio system for a wearable device dynamically updates acoustic transfer functions. The audio system is configured to estimate a direction of arrival (DoA) of each sound source detected by a microphone array relative to a position of the wearable device within a local area. The audio system may track the movement of each sound source. The audio system may form a beam in the direction of each sound source. The audio system may identify and classify each sound source based on the sound source properties. Based on the DoA estimates, the movement tracking, and the beamforming, the audio system generates or updates the acoustic transfer functions for the sound sources.