Measurement of Sound Fields Using Moving Microphones

TL;DR

This paper introduces a method for measuring sound fields with moving microphones, reducing the need for numerous fixed sensors by interpolating measurements along known trajectories to reconstruct the entire sound field.

Contribution

The paper presents a novel approach using moving microphones and spatial interpolation to efficiently measure and reconstruct sound fields, addressing calibration and sampling challenges.

Findings

Effective sound field reconstruction demonstrated

Reduced number of microphones needed

Flexible measurement effort versus sampling time

Abstract

The sampling of sound fields involves the measurement of spatially dependent room impulse responses, where the Nyquist-Shannon sampling theorem applies in both the temporal and spatial domain. Therefore, sampling inside a volume of interest requires a huge number of sampling points in space, which comes along with further difficulties such as exact microphone positioning and calibration of multiple microphones. In this paper, we present a method for measuring sound fields using moving microphones whose trajectories are known to the algorithm. At that, the number of microphones is customizable by trading measurement effort against sampling time. Through spatial interpolation of the dynamic measurements, a system of linear equations is set up which allows for the reconstruction of the entire sound field inside the volume of interest.