Audio Phase-Difference Filtering With On-Demand Coefficient Calculation

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Solution Overview

Problem

Conventional acoustic processing devices have limited filter degree of freedom due to pre-calculated filter coefficient groups stored in memory, making it difficult to adjust phase differences with high resolution and requiring significant storage for numerous coefficient groups.

Innovation Solution

An acoustic processing device that calculates filter coefficient groups based on input parameters such as center frequency, quality factor, and phase difference, allowing for arbitrary parameter settings and improved filter flexibility without the need for extensive memory storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If filter coefficient groups are pre-calculated and stored in memory under predetermined conditions, then the device complexity is reduced and processing speed is improved, but the degree of freedom of the filter is limited

Engineering Contradiction:

Improveprocessing speedVSAvoiddegree of freedom of the filter

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent pre-calculates and stores only the essential parameter combinations (center frequency, quality factor, phase difference at center frequency) in memory, rather than pre-calculating all possible filter coefficient groups. This preliminary action reduces memory storage requirements while maintaining the ability to generate arbitrary filter coefficients through real-time calculation based on the stored parameters.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediate calculation step where filter coefficients are generated on-demand from stored parameter groups rather than directly retrieving pre-calculated coefficients. This intermediary approach allows the system to maintain a compact set of parameter groups in memory while achieving high degrees of freedom through real-time coefficient generation based on these parameters.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If filter coefficient groups are calculated with each parameter finely changed to improve degree of freedom, then the adaptability of the filter is improved, but the calculation time and processing complexity increase enormously

Engineering Contradiction:

Improvedegree of freedom of the filterVSAvoidcalculation time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent changes the approach from calculating all possible parameter combinations to storing only the fundamental parameter groups (center frequency, quality factor, phase difference at center frequency) and deriving specific filter coefficients from these parameters when needed. This parameter-based approach maintains high adaptability while dramatically reducing calculation time by avoiding redundant computations of already-calculated parameter combinations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a compact representation of filter characteristics by storing parameter groups that can be used to generate multiple filter coefficient groups. Instead of storing numerous complete coefficient sets, the system stores essential parameters that define families of filters, effectively copying the ability to generate diverse filters from a minimal set of parameter definitions.

Inventive Principle:

Principle #26Copying

3Adaptability or versatility

If numerous filter coefficient groups are stored in memory to improve filter flexibility, then the degree of freedom of the filter is improved, but the memory storage requirements increase

Engineering Contradiction:

Improvefilter flexibilityVSAvoidmemory storage capacity

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the filter coefficient generation process into two parts: (1) storing essential parameter groups in memory, and (2) generating specific coefficients on-demand from these parameters. This segmentation allows the system to maintain a compact parameter database while achieving high filter flexibility through computational derivation rather than exhaustive storage.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20240072751A1Acoustic processing device and acoustic processing method

Publication Date: 2024.02.29 FAURECIA CLARION ELECTRONICS CO LTD

AI summary

An acoustic processing device unit is provided with: an input reception unit configured to receive an input of a value of a parameter defining a phase difference to be provided between a pair of audio signals; a filter coefficient calculation unit configured to calculate a filter coefficient group corresponding to each of the pair of audio signals based on the input value received by the input reception unit; and a filter processing unit configured to provide a phase difference defined by the input value between the pair of audio signals by performing filter processing on each of the pair of audio signals based on the filter coefficient group calculated by the filter coefficient calculation unit. The parameter above includes a center frequency of the phase difference provided between the pair of audio signals, a quality factor, and a phase difference at the center frequency.