Abstract

Dodecahedron sound sources are widely used for acoustical measurement purposes as they produce a good approximation of omnidirectional radiation. Evidence shows that such an assumption is acceptable only in the low-frequency range (namely below 1 kHz), while at higher frequencies sound radiation is far from being uniform. In order to improve the accuracy of acoustical measurements obtained from dodecahedron sources, international standard ISO 3382 suggests an averaging of results after a source rotation. This paper investigates the effects of such rotations, both in terms of variations in acoustical parameters and spatial distribution of sound reflections. Taking advantage of a spherical microphone array, the different reflection patterns were mapped as a function of source rotation, showing that some reflections may be considerably attenuated for different aiming directions. This paper investigates the concept of averaging results while changing rotation angles and the minimum number of rotations required to improve the accuracy of the average value. Results show that averages of three measurements carried out at 30° angular steps are closer to actual values and show much less fluctuation. In addition, an averaging of the directional intensity components of the selected responses stabilizes the spatial distribution of the reflections.

Autore Pugliese

• Martellotta Francesco

Tutti gli autori

• Martellotta F

Titolo volume/Rivista

THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA

Anno di pubblicazione

2013

ISSN

0001-4966

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

2016-06-13 05:28:31

Numero di citazioni Scopus

6

Ultimo Aggiornamento Citazioni

2016-06-18 03:27:06

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile