a PostgreSQL user-defined function.  The Metaphone system is a method of
matching similar sounding names (or any words) to the same code.

Metaphone was invented by Lawrence Philips as an improvement to the popular
name-hashing routine, Soundex.

This metaphone code is from Michael Kuhn, and is detailed at
   http://aspell.sourceforge.net/metaphone/metaphone-kuhn.txt

Joel Burton