TY - GEN
T1 - MEASUREMENT OF THE SOUND ABSORPTION COEFFICIENT OF MATERIALS IN A REVERBERANT CHAMBER USING AN OMNIDIRECTIONAL PARAMETRIC LOUDSPEAKER
AU - Martínez-Suquía, Carme
AU - Arnela, Marc
AU - Guasch, Oriol
N1 - Publisher Copyright:
© 2023 C. Martínez-Suquía et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2023
Y1 - 2023
N2 - The omnidirectional parametric loudspeaker (OPL) is a sound source that exploits the phenomenon of the parametric acoustic array (PAA) to produce an omnidirectional sound field. It consists of hundreds of ultrasound transducers distributed on the surface of a sphere. Each transducer emits an ultrasonic signal modulated in amplitude by an audible exponential sweep sine (ESS). The signal is demodulated back to the audible range by nonlinear propagation in air. This work investigates the suitability of the OPL for some room acoustics measurements. We focus on measuring the sound absorption coefficient of materials in a reverberant chamber. In fact, the study proposes the first steps towards a methodology to measure the absorption coefficient of materials, similar to ISO 354 standard, but for an OPL. The ESS is used as excitation signal because it allows the OPL to concentrate the emitted sound power on a single frequency, leading to higher ultrasonic power levels and increasing the signal-to-noise ratio of the audible sound pressure levels. The procedure for obtaining the frequency dependent reverberation times is also described. The absorption coefficient and reverberation times measured with the OPL are compared with those of conventional dodecahedral loudspeaker.
AB - The omnidirectional parametric loudspeaker (OPL) is a sound source that exploits the phenomenon of the parametric acoustic array (PAA) to produce an omnidirectional sound field. It consists of hundreds of ultrasound transducers distributed on the surface of a sphere. Each transducer emits an ultrasonic signal modulated in amplitude by an audible exponential sweep sine (ESS). The signal is demodulated back to the audible range by nonlinear propagation in air. This work investigates the suitability of the OPL for some room acoustics measurements. We focus on measuring the sound absorption coefficient of materials in a reverberant chamber. In fact, the study proposes the first steps towards a methodology to measure the absorption coefficient of materials, similar to ISO 354 standard, but for an OPL. The ESS is used as excitation signal because it allows the OPL to concentrate the emitted sound power on a single frequency, leading to higher ultrasonic power levels and increasing the signal-to-noise ratio of the audible sound pressure levels. The procedure for obtaining the frequency dependent reverberation times is also described. The absorption coefficient and reverberation times measured with the OPL are compared with those of conventional dodecahedral loudspeaker.
KW - exponential sine sweep
KW - omnidirectional parametric loudspeaker
KW - parametric acoustic array
KW - reverberation time
KW - room acoustics
UR - http://www.scopus.com/inward/record.url?scp=85191249587&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85191249587
T3 - Proceedings of Forum Acusticum
BT - Forum Acusticum 2023 - 10th Convention of the European Acoustics Association, EAA 2023
PB - European Acoustics Association, EAA
T2 - 10th Convention of the European Acoustics Association, EAA 2023
Y2 - 11 September 2023 through 15 September 2023
ER -