Wednesday, August 26, 2009

Soundex - The Basics

If you haven't already, at some point in your research, you will likely have a need to use one of the older Soundex indexes on microfilm. With that in mind, here are some basics about Soundex.

Soundex is an indexing system that is phonetic-based and groups together names that sound alike but are spelled differently, for example, Pearson, Pierson, and Pehrson. You can probably understand the need for such an indexing method, particularly for those of us whose ancestors surnames were spelled various ways throughout the years. This system of indexing was first developed in 1918, and was called the Russell Soundex. The American Soundex is a variation used for census records. A Miracode is a Soundex index card generated by computer. You might hear any or all of these terms used in research circles.

The Soundex index was used for U.S. federal census records starting with the 1880 census, and has also been used for some ship passenger arrival lists, naturalization records, and Canadian border crossings. Some counties also use a Soundex-type indexing system for certain county records. Many online genealogy databases use the Soundex concepts in their search feature.

The easiest way to determine a Soundex code for an ancestor's name is by using an online converter tool, and there are several of these out there. These include RootsWeb's Soundex Converter and Eastman's Online Genealogy Newsletter Soundex Calculator.

You can also create a Soundex code yourself if you know the basic system. Every soundex code consists of a letter and three numbers, such as C157. The letter is always the first letter of the name. After the first letter, ignore the vowels and the consonants H and W. Numbers are then assigned to the remaining letters of the name according to Soundex Key Letter Codes shown below. Zeroes are added at the end as necessary to get a 4-character code, and excess letters are ignored if they make a code longer than 4 characters.

Soundex Key Letter Codes

1 - b, f, p, v
2 - c, g, j, k, q, s, x, z
3 - d, t
4 - l
5 - m, n
6 - r

There are a few additional rules and plenty of examples of using the Soundex at FamilySearch's Wiki and at Eastman's Online Genealogy Newsletter, so I won't re-invent the wheel here on my blog. As always, the accuracy and effectiveness of your research will be greatly enhanced when you use all of the tools available to you, both new and old.