Surround Speaker Localization Using Time-of-Arrival Calibration

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Solution Overview

Problem

Existing surround sound systems face challenges in speaker placement and setup, particularly in environments with varying room sizes and dimensions, leading to non-optimal speaker positioning and a significant burden for users.

Innovation Solution

A method for automatic speaker discovery and localization using time-of-arrival (TOA) data from speakers and microphones, combined with a cost function minimization algorithm, to determine the optimal placement of speakers in a listening environment, accounting for variable latencies and environmental constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If strict speaker placement rules are defined for surround systems, then audio quality is improved, but device complexity and ease of operation deteriorate

Engineering Contradiction:
Improveaudio qualityVSAvoidspeaker placement complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-calibration by automatically measuring speaker positions using TOA measurements and cost function minimization, eliminating the need for manual placement procedures while ensuring optimal audio quality

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary automatic calibration measurements during setup to determine speaker positions before audio playback begins, storing these parameters for subsequent use without requiring repeated manual adjustment

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If automatic speaker discovery using TOA data and cost function minimization is implemented, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improvespeaker setup simplicityVSAvoidautodiscovery system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces manual mechanical speaker placement and measurement procedures with an automated acoustic field-based TOA measurement and computational cost function minimization system

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system transforms the speaker placement problem into a parameter optimization problem by minimizing a cost function based on TOA measurements, automatically determining optimal speaker positions without manual intervention

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables easy and accurate placement of speakers in multi-speaker systems, allowing for arbitrary placement and improving the audio experience by optimizing speaker positioning and reducing setup complexity.

Implementation Method 1

by determining Times-of-Arrival for each of the n speakers and m microphones

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP4235207B1Automatic discovery and localization of speaker locations in surround sound systems
Publication Date: 2026.01.28 DOLBY LABORATORIES LICENSING CORP
  • EP4235207B1 patent drawingFigure 1
  • EP4235207B1 patent drawingFigure 2
  • EP4235207B1 patent drawingFigure 3

AI summary

Embodiments are described for a method of simultaneously localizing a set of speakers and microphones, having only the times of arrival between each of the speakers and microphones. An autodiscovery process uses an external input to set: a global translation (3 continuous parameters), a global rotation (3 continuous parameters), and discrete symmetries, i.e., an exchange of any axis pairs and/or reversal of any axis. Different time of arrival acquisition techniques may be used, such as ultrasonic sweeps or generic multitrack audio content. The autodiscovery algorithm is based in minimizing a certain cost function, and the process allows for latencies in the recordings, possibly linked to the latencies in the emission.