Summary form only given, as follows. The design of balanced error-correcting codes has received a lot of attention in recent literature. Besides their error-control capability, these codes also have power spectral densities that make them attractive for use on the fiber optic channel and for data storage on magnetic tape. Since these codes are balanced, the number of ones in every code word equals the number of zeros. This property guarantees a null at DC in the power spectral densities of these codes. The authors show ways of constructing single error-correcting balanced codes with dmi n = 4. They construct code words by a two-layered method. They first define a set of balanced symbols consisting of a sequence of zeros and ones (with the number of ones equal to the number of zeros). Thus any sequence of these symbols will be balanced. The code words are constructed by concatenating these symbols in a way that guarantees the minimum distance of the code to be 4, i.e., dm in = 4.