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How To: Calculate the Soundex value for a street name

Summary

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.

Procedure

The Soundex function used in ArcGIS produces a single character followed by three digits. It is calculated using the following procedure:

  1. 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:
   Brookside
   Brksd 
  1. Digits are added to the Soundex value for up to the first three remaining letters according to the following table:
[O-Image] Soundex values
In the above example:
   Brksd
   B622 
Ignore spaces if the street name contains multiple words.
  1. 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:
   Vine
   Vn
   V500 

Related Information

Problem: Geocoding services cannot find the correct candidates for an address if there is a spelling error at the beginning of the street name