Measurement of sound radiation efficiency by the discrete calculation method

In the present paper, a newly developed measurement method of sound radiation efficiency, called the discrete calculation method (DCM), is presented, and the usefulness of DCM is verified by measurements of various vibrating objects. The proposed method is a hybrid method comprising both vibration measurement and calculation of radiation impedance. Since the proposed method does not require the measurement of sound fields, this method provides the following features, which conventional methods do not possess: (1) DCM can be applied to measurement in a low-frequency range and to a noisy sound field, such as construction sites; (2) high precision appears possible, because the sound radiation efficiency can be obtained without the sound measurement. These features, wide application and high precision, are essential for sound radiation measurement. The usefulness of the DCM as a measurement method for sound radiation is determined by performing measurements of various specimens.