This paper will describe a newly developed expert system which uses linguistic knowledge to align the phonetic content of two different words or phrases and score their similarity. The development of the system arose out of a need to have an automatic scoring algorithm for intelligibility testing for text‐to‐speech systems and other synthetic‐speech coding and recognition systems. The system uses an automatic text‐to‐phone algorithm to translate the input and reference ASCII text strings to phonemic units, aligns them using linguistic knowledge‐based decision criteria and a dynamic programming optimization, and outputs the aligned strings as well as tabulating the phoneme confusions.