Experimental sound power measurements following ISO standards with MEMS and Spherical Array (Comparison)

Punyakorn Sourachai Geonoise (Thailand), Bangkok, Thailand email: punyakorn@geonoise.asia

Pitipong Sarapho Geonoise (Thailand), Bangkok, Thailand email: pond@geonoise.asia

Sound power level determines the actual performance or strength of a sound source, which can range from a portable loudspeaker to gigantic machinery. Methods to measure sound power have been introduced since the 80s by the International Organization for Standardization (ISO), determining sound power with sound pressure in ISO 3740 series. Later, ISO 9614 series were introduced with methods based on sound intensity. Both methods have been adopted and are well-known throughout the field. Nowadays, the technology of MEMS microphones is widely spread in the industry, as well as the method of combining multiple microphones to form an array, allowing engineers to localize sound source location and capture multiple acoustic parameters simultaneously. This paper presents an experiment measuring sound power level with the RSS using conventional ISO methods from sound pressure and intensity known to be able to provide accuracy higher than survey grade, compared with a spherical array microphone that was more recently introduced. An in-situ measurement is also presented to experiment with the practicality of each method.

Theme areas: Acoustical and vibration measurement and instrumentation

Full paper available at https://www.aac.asia