SELECT contacts.id
FROM contacts
INNER JOIN (
    SELECT first_name, last_name, count(*) AS rows
    FROM contacts
    WHERE deleted = 0
    GROUP BY SOUNDEX(first_name), SOUNDEX(last_name)
    HAVING count(rows) > 1
) AS p
WHERE contacts.deleted = 0
AND p.first_name SOUNDS LIKE contacts.first_name
AND p.last_name SOUNDS LIKE contacts.last_name
ORDER BY contacts.date_entered DESC

[...] AND SOUNDEX(p.first_name) = SOUNDEX(contacts.first_name) [...]

SELECT c1.id as contact_id,
       c2.id as similar_id
  FROM contacts c1
  JOIN contacts c2
    ON c2.id <> c1.id
   AND c2.deleted = 0
   AND SOUNDEX(c2.first_name) = SOUNDEX(c1.first_name)
   AND SOUNDEX(c2.last_name) = SOUNDEX(c1.last_name)
 WHERE c1.deleted = 0
ORDER BY c1.date_entered DESC

SELECT c1.id as contact_id,
       c2.id as similar_id
  FROM contacts c1
  JOIN contacts c2
    ON c2.id <> c1.id
   AND c2.deleted = 0
   AND c2.first_name_soundex = c1.first_name_soundex
   AND c2.last_name_soundex = c1.last_name_soundex
 WHERE c1.deleted = 0
ORDER BY c1.date_entered DESC

SELECT SOUNDEX('cholmondley');
+------------------------+
| SOUNDEX('cholmondley') |
+------------------------+
| C4534                  |
+------------------------+

SELECT SOUNDEX('chumleigh');
+----------------------+
| SOUNDEX('chumleigh') |
+----------------------+
| C542                 |
+----------------------+