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Digital acoustic communication solid channels make it possible to send data through metallic barriers with up to very high rates while also transferring power and with lower complexity, lower size and power. This paper presents different techniques for achieving this including data transfer rates up to sever kilobits per second (kbps) using simple switching technique to many megabits per second through thick steel. Modulation techniques include Chirp-On-Off Keying (C-O-OK) to Orthogonal Frequency Division Multiplexing (OFDM) and even Multiple-Input Multiple -Output (MIMO) approaching 700 Mbps. Frequencies up to 4 MHz are used with piezoelectric elements propagating longitudinal waves or transversely polarized shear waves serving as the sending and receiver sensors.