SOUNDEX()

    SOUNDEX() converts a character string to soundex form (phonetic
complement) useful for INDEXing and searching.

Syntax

    SOUNDEX(<expC>)

Arguments

    <expC> is the character string to convert to soundex form.

Returns

    A character string.

    The string returns is a code in the form A9999.

Usage

    SOUNDEX() is useful for creating indexes and searching for strings
where the precise spelling is unknown.  SOUNDEX() is based on an
algorithm by Donald E. Knuth.

Knuth, Donald E. (1973).  Sorting and Searching.  The Art of
Computer Programming (Vol. 3),(p. 392).  Reading, MA: Addison
Wesley.