Technical & Applied Article

Real-time sound synthesis of pass-by noise: comparison of spherical harmonics and time-varying filters

¹ Siemens Digital Industries Software, Interleuvenlaan 68, 3001 Leuven, Belgium
² KU Leuven, Department of Mechanical Engineering, Celestijnenlaan 300 B, 3001 Leuven, Belgium
³ Siemens Digital Industries Software, 150 Avenue de la Republique, 92320 Chatillon, France
⁴ DMMS Core Lab, Flanders Make, Gaston Geenslaan 8, 3001 Heverlee, Belgium

^* Corresponding author: jacques.cuenca@siemens.com

Received: 3 May 2023
Accepted: 16 June 2023

Abstract

This paper proposes and compares two sound synthesis techniques to render a moving source for a fixed receiver position based on indoor pass-by noise measurements. The approaches are based on the time-varying infinite impulse response (IIR) filtering and spherical harmonics (SH) representation. The central contribution of the work is a framework for realistic moving source sound synthesis based on transfer functions measured using static far-field microphone arrays. While the SHs require a circular microphone array and a free-field propagation (delay, geometric spread), the IIR filtering relies on far-field microphones that correspond to the propagation path of the moving source. Both frameworks aim to provide accurate sound pressure levels in the far-field that comply with standards. Moreover, the frameworks can be extended to additional sources and filters (e.g. sound barriers) to create different moving source scenarios by removing the room size constraint. The results of the two sound synthesis approaches are preliminary evaluated and compared on a vehicle pass-by noise dataset and it is shown that both approaches are capable of accurately and efficiently synthesize a moving source.