Experimental study on performance of time reversal focusing

Acoustic focusing plays a dominant role in many acoustic functional devices, and it is a key for many acoustic-based applications. Time reversal (TR) focusing is a powerful focusing method for various types of waves, which re-engaged the attention of researchers with the development of metamaterials. In this paper, some visual acoustic experiments are carried out to study the realization method of self-adaptive airborne focusing in reverberating rooms based on TR method, as well as comprehensively analyze the focusing performance with different control variables of equipment and signal parameters. The results show that the TR self-adaptive focusing method can robustly work in an ordinary reverberating room even only with a few common speakers and one microphone, thus the cost would be greatly reduced due to the decrease of sensors. What's more, the signal parameters could be set over a wide range, which also extends the application range of the method. Therefore, the results of this work could fundamentally help broaden the application of the method. Since the TR focusing method has become a powerful wave manipulation and focusing tool, more novel physical phenomena are expected to be obtained by combining this method with the latest metamaterials. (paper)