Perl in a Nutshell, 2nd Edition

Text::Soundex

Implements the soundex algorithm, which hashes a word (in particular, a surname) into a compressed form that approximates the sound of the word when spoken by an English speaker:

use Text::Soundex;

$code = soundex $string;  # Get soundex code for a string
@codes = soundex @list;   # Get list of codes for list of strings

Returns the value of the variable $soundex_nocode if there is no soundex code representation for a string. $soundex_nocode is initially set to undef, but can be reset to another value. For example:

$soundex_nocode = 'Z000';