Source : Free On-Line Dictionary of Computing

metaphone
     
         An {algorithm} for encoding a word so that
        similar sounding words encode the same.  It's similar to
        {soundex} in purpose, but as it knows the basic rules of
        English pronunciation it's more accurate.  The higher accuracy
        doesn't come free, though, metaphone requires more
        computational power as well as more storage capacity, but
        neither of these requirements are usually prohibitive.  It is
        in the public domain so it can be freely implemented.
     
        Metaphone was developed by Lawrence Philips
        .  It is described in ["Practical
        Algorithms for Programmers", Binstock & Rex, Addison Wesley,
        1995].
     
        (1998-12-22)