What is Soundex?
Soundex is a phonetic coding system used to link surnames that are
spelled differently yet sound alike (i.e., homophones). The American
Soundex code was adopted by the federal government in the 1930's to
index federal and state census records from 1880, 1900 and 1910. It was
originally created using a system of handwritten index cards, which have
over time been microfilmed and/or digitized for current use. The
necessity for developing such a system is apparent to anyone who has
conducted genealogical work involving U.S. census records. If a surname
was spelled in a non-standard way on the census, Soundex links that name
to the standard spelling and other variations of that name found in the
census record. Here is an example taken from The Soundex Reference
Guide (1990):
Name Soundex Code
Stewart S363
Stuart S363
Steuart S363
Stuert S363
Steward S363
Steuard S363
Stuard S363
Multiple spellings of the "Stewart" surname are assigned the same
code and are grouped together in the Soundex. This makes finding unusual
spellings of a surname much easier when conducting genealogical work.
How does it work?
The basic rules for encoding surnames are:
-Use the first letter of the name as the first digit in the code.
-Convert consonants to the following numerical digits
1 = b,f,p,v
2 = c,g,j,k,q,s,x,z
3 = d,t
4 = l
5 = m,n
6 = r
-If a letter is doubled, only use the first occurrence of the letter.
For the name "Miller" use only the first "L" and skip to the "R" as the
second consonant.)
-Repeat the three steps above. The end product should consist of one
letter and three numbers. If there are not enough consonants in a name,
add a "0" as a place holder. For the name "Miller" the code is M460; "M"
is for Miller, "4" is for the first "L," "6" represents the "R" and the
"0" indicates the lack of subsequent consonants.
How is Soundex used today?
I was inspired to research Soundex coding when I discovered the code
for my last name was also the first four digits of my driver's license
number. In many states Soundex or Miracode coding systems are used every
day to assign identification numbers to driver's licenses and state
issued identification cards. In Illinois the code is as follows: the
1st section of digits represents last name, digits 4-5-6 represent first
name and middle initial, digits 7 and 8 are the last two digits of a
person's birth year, and the last three digits represent birth month and
day. There is a coding system to these numbers and one can easily
access a key
online if interested in learning more.
Genealogy resources such as Ancestry.com and Heritage Quest use
Soundex as a default search setting for the researcher's convenience.
Researchers can change these settings if a Soundex match is not wanted.
Heritage Quest also contains a .pdf document under the "Help with the
Federal Census" section that contains a Soundex and Miracode Coding
Guide and an Explanation of the Soundex and Miracode Indexing System.
