“…After collecting audio data, they need to undergo preprocessing techniques that clean and transform them for classification. Most bioacoustics [ 48 , 49 , 50 , 51 , 53 , 54 , 61 , 62 , 63 , 64 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 81 , 82 , 86 ], and general acoustic [ 113 , 114 , 115 , 117 , 118 , 120 , 121 , 123 , 124 , 126 , 132 , 135 , 137 , 138 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 149 , 153 , 154 ] studies did not describe the preprocessing techniques that they used. An analysis of the studies that mentioned preprocessing revealed the most popular audio transformation technique as STFT (short-time Fourier transform) among both the bioacoustics [ 52 , 60 <...…”