Sound Processing Apparatus Transfer Function Estimation

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Solution Overview

Problem

Existing sound processing technologies cannot accurately estimate transfer functions in room environments without using a measuring sound source, as they depend on specific positional relationships between microphones and sound sources, which vary with room characteristics such as size, reflection coefficients, and object presence.

Innovation Solution

A sound processing apparatus and method that calculates sound collection positions and sound source directions using sound signals, allowing for the estimation of transfer functions in desired sound source directions by interpolating first transfer functions using a geometric model, without requiring a measuring sound source. This involves a sound collection position calculating unit, a sound source direction calculating unit, and transfer function calculating units that use inter-channel time differences and state prediction to update sound source state information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a measuring sound source is used to calculate transfer functions, then the accuracy of transfer function estimation is improved, but the complexity of the system increases and a separate measuring sound source is required

Engineering Contradiction:

Improvetransfer function estimation accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the hearing sound source itself (e.g., human speech) to estimate transfer functions, eliminating the need for a separate measuring sound source. The sound processing apparatus processes the sound signals from the hearing sound source to calculate transfer functions, making the system self-sufficient without additional measuring equipment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The sound processing apparatus serves multiple functions: it processes hearing sound sources for recognition purposes and simultaneously uses these same sound sources to estimate transfer functions. This multi-functionality eliminates the need for dedicated measuring sound sources while maintaining measurement accuracy.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If transfer functions are calculated based on specific positional relationships between microphones and sound sources, then the calculation accuracy is improved, but the adaptability to different room environments deteriorates

Engineering Contradiction:

Improvetransfer function calculation accuracyVSAvoidroom environment adaptability

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts to different room environments by using sound signals actually present in the environment to estimate transfer functions. Instead of relying on fixed positional relationships, the apparatus processes real sound signals to calculate transfer functions that reflect the current room characteristics, making the system adaptable to various acoustic conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The transfer function estimation process adapts to different room environments by changing the parameters based on the actual sound signals received. The system calculates transfer functions using inter-channel time differences and sound collection positions derived from real acoustic measurements, allowing the parameters to adjust according to the specific room acoustics.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If sound collection positions are estimated using sound signals, then the need for additional measuring equipment is eliminated, but the estimation accuracy may deteriorate due to varying acoustic conditions

Engineering Contradiction:

Improvemeasuring equipment requirementVSAvoidsound collection position estimation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The system uses feedback from the sound signals themselves to estimate sound collection positions and transfer functions. By processing the actual hearing sound sources and using inter-channel time differences, the apparatus continuously refines its position estimates based on the acoustic feedback from the environment, maintaining accuracy without additional measuring equipment.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10139470B2Sound processing apparatus and sound processing method

Publication Date: 2018.11.27 HONDA MOTOR CO LTD

AI summary

A sound processing apparatus includes a sound collection position calculating unit configured to calculate sound collection positions of sound signals of multiple channels on the basis of the sound signals, a sound source direction calculating unit configured to calculate a sound source direction on the basis of the sound signals of multiple channels, a first transfer function calculating unit configured to calculate a first transfer function corresponding to the sound source direction on the basis of the sound signals of multiple channels, and a second transfer function calculating unit configured to calculate a second transfer function by interpolating the first transfer function corresponding to each of a plurality of sound source directions.