“…Thus, the direction of sound propagation can be obtained by measuring the direction of acoustic particle velocity. TAPVS shows promising properties for applications in sound source localization [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ], such as engine fault detection [ 14 , 15 , 16 , 17 ], gunshot localization [ 18 , 19 ], and pipe leakage acoustic detection [ 7 , 20 ] etc., which is far superior to microphone arrays for its higher orientation accuracy, smaller size, simpler signal processing [ 21 ], wider working temperature range [ 22 ], lower low frequency self-noise [ 4 , 23 ], and so on.…”