When a database is set to be compatible with SQL Server 2011, the behavior of the SOUNDEX string function changes. Specifically, ...

When a database is set to be compatible with SQL Server 2011, the behavior of the SOUNDEX string function changes. Specifically, from the Soundex standard defined the National Archives available at http://www.archives.gov/genealogy/census/soundex.html, coding rule #2 (Names with Letters Side-by-Side that have the Same Soundex Code Number) will be enforced even if the side-by-side happens between the first two letters of the name, which was not the case in previous versions of SQL Server. Also we will enforce coding rule #4 (Consonant Seperators) in the "H" and "W" cases.