Online Single-Channel Audio-Based Sound Speed Estimation for Robust Multi-Channel Audio Control
This work addresses the practical need for robust spatial audio control in systems with minimal sensing, offering a calibration-free method to handle environmental variations.
The paper proposes an online sound speed estimator that requires only a single microphone and operates during general multichannel audio playback. Simulations demonstrate accurate tracking of sound speed and improved spatial control performance in a sound zone control framework.
Robust spatial audio control relies on accurate acoustic propagation models, yet environmental variations, especially changes in the speed of sound, cause systematic mismatches that degrade performance. Existing methods either assume known sound speed, require multiple microphones, or rely on separate calibration, making them impractical for systems with minimal sensing. We propose an online sound speed estimator that operates during general multichannel audio playback and requires only a single observation microphone. The method exploits the structured effect of sound speed on the reproduced signal and estimates it by minimizing the mismatch between the measured audio and a parametric acoustic model. Simulations show accurate tracking of sound speed for diverse input signals and improved spatial control performance when the estimates are used to compensate propagation errors in a sound zone control framework.