Sound Source Localization Using Sparse Interaural Time Difference Extraction

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Solution Overview

Problem

Existing sound source localization techniques for robots face challenges in accurately localizing sound sources due to environmental changes and the complexity of measuring impulse responses, especially when using microphone arrays that mimic human hearing, which are sensitive to platform variations and interference from facial structures.

Innovation Solution

A sound source localization system utilizing sparse coding and a self-organized map (SOM) to extract sparse interaural time differences (SITDs) from microphone signals, allowing for adaptation to various platforms and environments without the need for repeated impulse response measurements, and employing a neural network model inspired by human auditory processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If HRTF-based sound source localization is used to account for platform influences, then localization accuracy is improved, but measurement complexity increases due to the need for impulse response measurements in dead rooms for each platform configuration

Engineering Contradiction:
Improvesound source localization accuracyVSAvoidmeasurement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual model (copy) of the head and ear structures that replicates the acoustic characteristics of the physical platform. This virtual model is used to generate HRTF data through simulation, eliminating the need for physical impulse response measurements in anechoic chambers while maintaining localization accuracy.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical measurement system (physical impulse response measurements in dead rooms) with a computational simulation system. By using numerical methods to solve the acoustic wave equation, the system obtains HRTF data without requiring complex physical measurement setups.

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

2Ease of operation

If traditional sound source localization systems are used, then they can operate in simple environments, but they require program modifications to adapt to environmental changes

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidenvironmental adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic adaptation mechanism where the system continuously learns from environmental acoustic characteristics and adjusts its localization parameters accordingly. This allows the system to adapt to different environments (rooms, outdoor spaces, etc.) without requiring manual reconfiguration or program modifications.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs self-calibration by automatically characterizing the acoustic environment and adjusting its HRTF models accordingly. This self-service capability eliminates the need for external intervention or complex setup procedures when deploying the system in new environments.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If microphone arrays with specific structures are used for sound source localization, then localization can be achieved in ideal conditions, but performance degrades when platform influences and facial structures interfere with sound signal flow

Engineering Contradiction:
Improvesound source localization accuracyVSAvoidplatform and facial structure interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent creates detailed virtual models of the head, ears, and facial structures that accurately replicate how these physical structures modify sound signals. By simulating the acoustic interactions between sound waves and these structures in the virtual model, the system compensates for their interfering effects and maintains localization accuracy.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS8270632B2Sound source localization system and method
Publication Date: 2012.09.18 KOREA INST OF SCI & TECH
  • US8270632B2 patent drawing
  • US8270632B2 patent drawing
  • US8270632B2 patent drawing

AI summary

A sound source localization system includes a plurality of microphones for receiving a signal as an input from a sound source; a time-difference extraction unit for decomposing the signal inputted through the plurality of microphones into time, frequency and amplitude using a sparse coding and then extracting a sparse interaural time difference (SITD) inputted through the plurality of microphones for each frequency; and a sound source localization unit for localizing the sound source using the SITDs. A sound source localization method includes receiving a signal as an input from a sound source; decomposing the signal into time, frequency and amplitude using a sparse coding; extracting an SITD for each frequency; and localizing the sound source using the SITDs.