Speaker Array Sound Field Control Using Depth-Adjusted Control Points

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Solution Overview

Problem

Sound field forming technology using speaker arrays struggles to maintain high reproducibility of wavefronts for listeners positioned far from the control points, leading to significant errors in forming ideal sound fields, especially when multiple listeners are at different distances from the speaker array.

Innovation Solution

The solution involves specifying multiple control points in the depth direction for each listener based on their position and the sound source position, generating unique speaker drive signals for each control point, and combining them to enhance wavefront reproducibility across the listening area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a fixed control point is set for one listener, then the wavefront reproducibility at that listener's position is improved, but the wavefront reproducibility at other listeners' positions (especially those far from the control point) deteriorates

Engineering Contradiction:
Improvewavefront reproducibilityVSAvoidadaptability to multiple listener positions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent divides the listening area into multiple zones, each associated with a specific control point. Instead of using a single control point for the entire area, the system segments the space and assigns dedicated control points to different regions, ensuring that each listener position has an optimized control point for accurate wavefront reproduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic selection of control points based on the listener's position. The control point assignment is not fixed but changes dynamically according to where the listener is located in the listening area, allowing the system to adapt to multiple positions while maintaining high wavefront reproducibility at each position.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If listeners are positioned at different distances from the speaker array, then the system can serve multiple listeners simultaneously, but the error between formed sound field and targeted ideal sound field increases for listeners far from control points

Engineering Contradiction:
Improveability to serve multiple listeners at different positionsVSAvoidsound field formation accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies different control point assignments to different spatial locations. Each region of the listening area has its own optimized control point characteristics, allowing the system to maintain high sound field formation accuracy locally at each position while serving multiple listeners at various distances from the speaker array.

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If the listening area is extended to cover larger distances from the speaker array, then the coverage area is improved, but the wavefront reproducibility deteriorates in regions far from the reference line

Engineering Contradiction:
Improvelistening area coverageVSAvoidwavefront reproducibility
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent extends the control point assignment in the depth direction (perpendicular to the speaker array), adding a new dimension to the control structure. By establishing control points at different depths, the system expands the effective listening area while maintaining wavefront reproducibility across the extended region.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3823301B1Sound field forming apparatus and method and program
Publication Date: 2023.08.23 SONY GROUP CORP

AI summary

The present technology relates to a sound field forming apparatus and method and a program that are configured to enhance the reproducibility of a wavefront at a listener position. The sound field forming apparatus (11) has a position acquisition unit (21) configured to acquire position information indicative of a position of a listener or a position of a sound source to be formed. Further, the sound field forming apparatus has a control point specification unit (23) configured to specify a control point in accordance with a distance from a speaker array (26) of the listener or the sound source on a basis of the position information. In addition, the sound field forming apparatus has a filter unit (25) configured to generate a speaker drive signal for forming a predetermined sound field by the speaker array by arranging a filter coefficient corresponding to the specified control point with a sound source signal.