Communication devices, such as a radio and a cockpit communication panel, digitally communicate audio signals as digital data without use of a synchronizing clock signal between the devices. The communication panel and the radio function as both a receiver and as a transmitter of digital audio signals. In one embodiment, an analog audio signal is received by the transmitting device and transformed by a coder/decoder (CODEC) into a plurality of signals. The plurality of signals is received and transformed by a field programmable gate array (FPGA) into a digital signal that includes framing pulse and stop bits. The digital signal is transmitted to a FPGA in a receiving device, which transforms the signal into a second plurality of signals. A CODEC in the receiving device transforms the second plurality of signals into an analog audio signal.