Soundex( StringToCheck )

4 Char Soundex code. The weight is calculated as follows:

• all chars not in [a-z] or [A-Z] -> -1
• the chars [aeiouyhw] -> ignored
• chars [bfpv] -> 1
• chars [cgjkqsxz] ->2
• chars [dt] ->3
• chars[l] ->4
• chars[mn] ->5
• chars[r] ->6

If the returned soundex code is 2 or 3 chars, then 0 chars are appended

If the returned soundex code is more than 4 chars, then all chars after the 4th char will be ignored.

Soundex("sneider") ==  Soundex("snider")