Multi-source time reversal focusing for airborne sound

The time-reversal (TR) technique is universally acknowledged as dominant roles in acoustic applications. In this paper, implementation schemes for multi-source TR focusing on airborne sound were systematically investigated. An improved version of the traditional scheme was introduced according to the principle of reciprocity. Variations in multi-source TR focusing based on the improved focusing scheme were proposed, which included the multi-group focusing method and the signal superposition method. Furthermore, the traditional focusing scheme was extended to verify the adaptability of multi-source focusing experimentally. The performance and realization complexity of the three variations were discussed to identify the best scheme. This work extended the TR method from a single source to multi source situations via the superposition method, which is superior to existing techniques and simplifies the scenarios of multi-source focusing, therefore, promoting acoustic focusing research and application. (C) 2020 Elsevier Ltd. All rights reserved.