On Time Delay Interpolation for Improved Acoustic Reflector Localization

2025-09-04

AI Summary

Conventional time-delay estimation (TDE) methods are fundamentally limited to integer-multiple-of-sampling-period resolution, resulting in insufficient localization accuracy of acoustic reflectors in reverberant environments. To address this, we propose a sub-sample-level time-delay interpolation method tailored for short-time-window TDE. Leveraging theoretical derivation, we apply the Whittaker–Shannon interpolation formula under critical sampling and band-limited conditions, thereby significantly enhancing TDE resolution. Compared with standard sinc interpolation, our approach systematically reduces both temporal and spatial localization errors while preserving computational feasibility. Comprehensive validation—using synthetic data, real-world acoustic measurements, and the MYRiAD dataset—demonstrates that the proposed method achieves stable, robust, and consistently superior localization performance across diverse sensor-reflector configurations. This work establishes a generalizable theoretical framework and a practical toolset for high-precision passive acoustic localization.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Active Learning
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics
• Systems and Infrastructure for Web, Mobile and WoT: Location- and context-aware Web and WoT applications and services
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

The localization of acoustic reflectors is a fundamental component in various applications, including room acoustics analysis, sound source localization, and acoustic scene analysis. Time Delay Estimation (TDE) is essential for determining the position of reflectors relative to a sensor array. Traditional TDE algorithms generally yield time delays that are integer multiples of the operating sampling period, potentially lacking sufficient time resolution. To achieve subsample TDE accuracy, various interpolation methods, including parabolic, Gaussian, frequency, and sinc interpolation, have been proposed. This paper presents a comprehensive study on time delay interpolation to achieve subsample accuracy for acoustic reflector localization in reverberant conditions. We derive the Whittaker-Shannon interpolation formula from the previously proposed sinc interpolation in the context of short-time windowed TDE for acoustic reflector localization. Simulations show that sinc and Whittaker-Shannon interpolation outperform existing methods in terms of time delay error and positional error for critically sampled and band-limited reflections. Performance is evaluated on real-world measurements from the MYRiAD dataset, showing that sinc and Whittaker-Shannon interpolation consistently provide reliable performance across different sensor-source pairs and loudspeaker positions. These results can enhance the precision of acoustic reflector localization systems, vital for applications such as room acoustics analysis, sound source localization, and acoustic scene analysis.

Problem

• Improving acoustic reflector localization via time delay interpolation
• Achieving subsample accuracy in time delay estimation methods
• Enhancing precision for room acoustics and sound analysis

Innovation

• Using sinc and Whittaker-Shannon interpolation methods
• Achieving subsample time delay estimation accuracy
• Enhancing acoustic reflector localization in reverberant conditions