double metaphone


Definition: An algorithm to code English words (and foreign words often heard in the United States) phonetically by reducing them to a combination of 12 consonant sounds. It returns two codes if a word has two plausible pronunciations, such as a foreign word. This reduces matching problems from wrong spelling.

Generalization (I am a kind of ...)
phonetic coding algorithm.

See also Jaro-Winkler, Caverphone, NYSIIS, soundex, metaphone, Levenshtein distance.

Note: This is an improved version of metaphone. In 2009 Lawrence Philips produced Metaphone 3, which reportedly "increases the accuracy of phonetic encoding".

Author: PEB


Many metaphone and double metaphone (Basic, C, Perl, and C++) implementations. Apache codec implementations of soundex, Metaphone, and Double Metaphone (Java).

More information

Lawrence Philips, The Double Metaphone Search Algorithm, C/C++ Users Journal, June 2000. on-line article accessed October 2013.

Go to the Dictionary of Algorithms and Data Structures home page.

If you have suggestions, corrections, or comments, please get in touch with Paul Black.

Entry modified 19 July 2021.
HTML page formatted Mon Jul 19 10:37:07 2021.

Cite this as:
Paul E. Black, "double metaphone", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed. 19 July 2021. (accessed TODAY) Available from: