The Soundex function produces index values for English language strings. These values can be used to search for phonetically similar strings within a dataset.
ArcGIS uses an implementation of the Soundex function to index street names for geocoding services.
The Soundex function used in ArcGIS produces a single character followed by three digits. It is calculated using the following procedure:
- The first letter of the street name is retained, and all occurrences of a, e, h, i, o, u, w, and y in the remainder of the street name are dropped. For example:
- Digits are added to the Soundex value for up to the first three remaining letters according to the following table:
In the above example:
Ignore spaces if the street name contains multiple words.
- If fewer than three letters remain in the street name, trailing zeros are added to produce a Soundex value that is a single character followed by three digits. For example: