Experimental Active Noise Control Using Faust On FPGA: Comparison Between A Multi-Point and Spherical Harmonics Method

Loïc Alexandre (1) , Pierre Lecomte (1, 2) , Marie-Annick Galland (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique
2 UCBL - Université Claude Bernard Lyon 1

Active noise control over an extended area is usually performed using multi-point pressure minimization. Recent advances in approaches using spherical harmonics, i.e. ambisonics, show to be attractive to control three dimensional acoustic fields. However, to this day, only few experimental results are reported in the literature. This paper proposes a preliminary experimental multichannel active noise control system implemented on a FPGA using the Faust programming language. Two multichannel Filtered-x LMS algorithms are tested to minimize either multi-point pressure or ambisonic components of the sound field. Both methods use the same four-microphone and four-loudspeaker geometrical arrangement which allows to work with first order ambisonics. A focus is made on the practical implementation of such systems to account for the difficulties associated with causality and computational load. The latter are solved to propose an operational real-time adaptive system. Experimental results are reported and show effective noise attenuation for both methods.

Mots clés: Active Noise Control; Ambisonics; FPGA

Domaines: Acoustique [physics.class-ph]

Loïc Alexandre, Pierre Lecomte, Marie-Annick Galland. Experimental Active Noise Control Using Faust On FPGA: Comparison Between A Multi-Point and Spherical Harmonics Method. Forum Acusticum 2023 - 10th Convention of the European Acoustics Association, European Acoustics Association, Sep 2023, Torino, Italy. ⟨hal-04221590⟩