The invention relates to a method for coding information symbols of an alphabet into random acoustic signals. The coding dictionary is constructed in a heuristic manner by acquiring a set of random signals, by filtering same by way of the equivalent filter of the transmission channel, by selecting subsets of these signals, and, for each subset, by calculating the correlation matrix of the selected signals, the coding dictionary being constituted by the subset for which the correlation matrix most closely resembles a diagonal matrix. The invention also relates to a method for transmitting and receiving information symbols by way of acoustic signals.