This is not very easy to do with SQL Server. soundex/difference that Viroel mentioned are very rudimentary. Nor is fulltext of much use here.
The best fit in the SQL Server family is Data Quality Services which is an optional install. It is aimed to handles situations like this, but it has not gotten much love since it was introduced in SQL 2012, and the algorithms it uses have awful performance.
There are better tools from other vendors. Unfortunately, I don't have any names, as I have not worked in this space myself. I have only attended a presentations where the presenter discussed a couple of solutions - and was very clear on how poor DQS is.