Metaphone - Common Misconceptions

Common Misconceptions

There are a couple of misconceptions about the Metaphone algorithms that should be addressed:

1. All of them are designed to address regular, "dictionary" words, not just names, and
2. Metaphone algorithms do not produce phonetic representations of the input words and names; rather, the output is an intentionally approximate phonetic representation, according to this standard:

• words that start with a vowel sound will have an 'A', representing any vowel, as the first character of the encoding (in Double Metaphone and Metaphone 3 - original Metaphone just preserves the actual vowel),
• vowels after an initial vowel sound will be disregarded and not encoded, and
• voiced/unvoiced consonant pairs will be mapped to the same encoding. (Examples of voiced/unvoiced consonant pairs are D/T, B/P, Z/S, G/K, etc.).

This approximate encoding is necessary to account for the way English speakers vary their pronunciations and misspell or otherwise vary words and names they are trying to spell. Vowels, of course, are notoriously highly variable. British speakers often complain that Americans seem to pronounce 'T's the same as 'D'. Consider, also, that all English speakers often pronounce 'Z' where 'S' is spelled, almost always when a noun ending in a voiced consonant or a liquid is pluralized, for example "seasons", "beams", "examples", etc. Not encoding vowels after an initial vowel sound will help to group words where a vowel and a consonant may be transposed in the misspelling or alternate pronunciation.