Michael G Schwern


Text::Metaphone - A modern soundex. Phonetic encoding of words.


  use Text::Metaphone;

  # XWRN
  my $phoned_word = Metaphone('Schwern');


Metaphone() is a function whereby a string/word is broken down into a rough approximation of its english phonetic pronunciation. Very similar in concept and purpose to soundex, but much more comprehensive in its approach.



    $phoned_word = Metaphone($word, $max_phone_len);

Takes a word and encodes it according to the Metaphone algorithm. The algorithm only deals with alphabetical characters, all else is ignored.

If $max_phone_len is provided, Metaphone will only encode up to that many characters for each word.

'sh' is encoded as 'X', 'th' is encoded as '0'. This can be changed in the metaphone.h header file.


Metaphone algorithm changes

I have made a few minor changes to the traditional metaphone algorithm found in the books. The most significant one is that it will differenciate between SCH and SCHW making the former K (As in School) and the latter sh (as in Schwartz and Schwern).

My changes can be turned off by defining the USE_TRADITIONAL_METAPHONE flag in metaphone.h.

Due to these changes, any users of Metaphone v1.00 or earlier which have stored metaphonetic encodings, they should recalculate those with the new version.


Michael G Schwern <schwern@pobox.com>


Man pages

Text::Soundex - A simpler word hashing algorithm Text::DoubleMetaphone - Improved metaphone Text::Phonetic - A collection of phonetic algorithms

Books, Journals and Magazines

Binstock, Andrew & Rex, John. "Metaphone: A Modern Soundex." Practical Algorithms For Programmers. Reading, Mass: Addion-Wesley, 1995 pp160-169

Contains an explanation of the basic metaphone concept & algorithm and C code from which I learned of Metaphone and ported this module.

Parker, Gary. "A Better Phonetic Search." C Gazette, Vol. 5, No. 4 (June/July), 1990.

This is the public-domain C version of metaphone from which Binstock & Rex based their own.. I haven't actually read it.

Philips, Lawrence. Computer Language, Vol. 7, No. 12 (December), 1990.

And here's the original Metaphone algorithm as presented in Pick BASIC.


Copyright (c) 1997, 1999, 2007-2008 Michael G Schwern. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.