Soundex (Statutory and Census)
Using Soundex On Surnames in Statutory and Census Searches
Soundex is a system whereby names are grouped phonetically. It works by converting each name into a code or 'key', which consists of the first letter of the name followed by three numbers, determined according to the grouping of the consonants within the name. For example, CALLISON has the value C425. In a search, soundex will retrieve all entries with the same code as the search name.
See below for further information on how to calculate the soundex value of a name.
Note: You cannot use soundex and wildcards on a surname at the same time, but you can use wildcards on the forename during a surname soundex search.
Limitations of Soundex
- Due to its reliance on consonant groupings, soundex can generate large numbers of false positive results. For example, a soundex search on CAIRNS will return CAIRNS, CAIRENS, CARINS, CARNES, but also CARMICHAEL, CARNEGIE, CORMACK, CRANSTON, etc.
- Since the first letter of the name is used to generate the code, any name which sounds similar to the search name, but which varies on the first letter, will not be returned. For example, CAIRNS (C652) and KEARNS (K652).
- Not all phonetic variants of a name will be picked up, even if they have the same first letter, because different values are assigned to them. For example, LEIGHTON (L235) with soundex enabled will also return LAUGHTON, LAXTON, LEGHTON, LIGHTON, LISDON, LISTON, LOCHADAN, LOCKADAN, LUGTION, LUGTON, which have the same code, but not an obvious phonetic variant like LAYTON, which has a different code (L350).
- If you use soundex on the surname in statutory searches, the database will return only exact matches for the forename. Entries bearing other forenames and those where the chosen forename appears as a second or subsequent forename, will not be included. For example, a search for ANN MURRAY with Soundex enabled on the surname will return ANN MURRAY, ANN MAIR, ANN MOIR, ANN MUIR etc, but not ANN ELIZA MURRAY and not MARY ANN MOIR, etc. If you wish the search to include other forenames, you should employ the wildcard * on the forename. For example, a search on ANN* MURRAY with Soundex enabled on the surname will find ANN ELIZA MURRAY and ANNIE KING MOIR etc. A search on *ANN MOIR with Soundex enabled on the surname will find ELIZABETH ANN MOIR, JANE ANN MURRAY etc.
- Mc/Mac surnames using soundex soundex can be used to find variations of Mc and Mac, but you may find that a large number of superfluous results are returned and some relevant results are missed. For example, searching for MCDONALD with Soundex enabled returns McDONALD and MACDONALD, but also MACDONNELL, MCADAM, MCDONOUGH and many others. Since entries where the chosen forename appears as a second or subsequent forename are not included in a Soundex surname search, a better option would be to employ the wildcard * when searching for Mc and Mac surnames (see Wildcards), or to search them separately.
The Soundex Algorithm
The soundex code assigned to each name consists of the first letter of the name, followed by three numbers. These numbers are determined by the configuration of consonants in the name.
To calculate the soundex value of a name:
- The first letter of the name becomes the letter at the start of the code.
- The letters a, e, i, o, u, h, w and y are discounted, when not appearing as the first letter. Hyphens, apostrophes and spaces are also ignored.
- The remaining consonants in the name are assigned a number according to the following table:
- b, f, p, v
- c, g, j, k, q, s, x, z
- d, t
- m, n
- Once the 3-digit limit is achieved, the remaining letters are ignored, e.g. DOUGLAS-HUME will be D242, the same as DOUGLAS.
- Double consonants are treated as one, e.g. in MORRISON, the second 'r' is ignored and the values for r, s and n give it a code of M625.
- Adjacent letters with the same number value are coded as one, e.g. in ERSKINE the s and the k have the same number value, therefore the k is ignored and the code becomes E625.
- If there are not enough letters to make 3 numbers, the remaining digits are set to 0, e.g. DYE becomes D000.
- If the letter immediately following the starting letter is from the same group, it is ignored, e.g. SCOBIE is S100, not S210 and SCRIMGEOUR is S652, not S265.
- Mc, Mac and O' are not treated as prefixes but are coded as part of the name, e.g. MCDONALD is M235, MACDONALD is M235 and O'ROURKE is O662.
- The so-called 'H and W' rule whereby consonants from the same group, when separated by an H or W, are treated as a single letter, does not apply on this site, e.g. SACHS codes to S220 not to S200.
Find out about using Soundex On Surnames in OPR and Wills & Testaments Searches