Acoustic core segments include splicing resonant cells that resemble a first segment of a whole resonant cell configured to overlap and align with counterpart splicing resonant cells of another acoustic core segment so as to define a splice joint. The splicing resonant cells include one or more fastening elements configured to couple with corresponding counterpart splicing resonant cells thereby together defining coupled resonant cells. Acoustic liners have an acoustic core assembly that includes a first acoustic core segment mechanically joined with a second acoustic core segment by a combination of splicing resonant cells of the first acoustic core segment overlapping and aligning with splicing resonant cells of the second acoustic core segment so as to define a splice joint, and a plurality of fastening elements coupling splicing resonant cells of the first acoustic core segment with splicing resonant cells of the second acoustic core segment.