Abstract: Apparatus for enhancing the bit error rate performance of a storage medium, such as magnetic tape, magnetic disk, optical disk, or an equivalent thereof, includes two data transmission channels for recording in duplicate a stream of data bits corresponding to an information-bearing signal, each recorded bit stream being potentially influenced by a pattern of statistically distributed recording surface defects. During playback, error detection and correction circuitry for each channel provides an alarm signal synchronized with each uncorrected error condition in the corresponding stream of playback bits. A control circuit, responsive to the alarm signals from each channel, serves to interleave error-free bits from one channel, to the exclusion of error bits from the other channel, to provide a single continuous stream of relatively error-free bits corresponding to the information-bearing signal recorded.