caverphone

The Caverphone was created by David Hood in the Caversham Project at the University of Otago in New Zealand in 2002, revised in 2004. It was created to assist in data matching between late 19th century and early 20th century electoral rolls, where the name only needed to be in a "commonly recognisable form". The algorithm was intended to apply to those names that could not easily be matched between electoral rolls, after the exact matches were removed from the pool of potential matches. The algorithm is optimised for accents present in the study area (southern part of the city of Dunedin, New Zealand).

The rules of the algorithm are applied consecutively to any particular name, as a series of replacements.

The algorithm is as follows:

1. Convert to lowercase
2. Remove anything not A-Z
3. If the name starts with...
4. cough, replace it by cou2f
5. rough, replace it by rou2f
6. tough, replace it by tou2f
7. enough, replace it by enou2f
8. gn, replace it by 2n
9. If the name ends with
10. mb, replace it by m2
11. Replace
12. cq with 2q
13. ci with si
14. ce with se
15. cy with sy
16. tch with 2ch
17. c with k
18. q with k
19. x with k
20. v with f
21. dg with 2g
22. tio with sio
23. tia with sia
24. d with t
25. ph with fh
26. b with p
27. sh with s2
28. z with s
29. any initial vowel with an A
30. all other vowels with a 3
31. 3gh3 with 3kh3
32. gh with 22
33. g with k
34. groups of the letter s with a S
35. groups of the letter t with a T
36. groups of the letter p with a P
37. groups of the letter k with a K
38. groups of the letter f with a F
39. groups of the letter m with a M
40. groups of the letter n with a N
41. w3 with W3
42. wy with Wy
43. wh3 with Wh3
44. why with Why
45. w with 2
46. any initial h with an A
47. all other occurrences of h with a 2
48. r3 with R3
49. ry with Ry
50. r with 2
51. l3 with L3
52. ly with Ly
53. l with 2
54. j with y
55. y3 with Y3
56. y with 2
57. remove all
58. 2
59. 3
60. put six 1 on the end
61. take the first six characters as the code

1. Start with a word
2. Convert to lowercase
3. Remove anything not in the standard alphabet (typically a-z){{notetag|This may vary if the set of letters includes characters such as æ, ā, or ø }}
4. Remove final e
5. If the name starts with
6. cough make it cou2f
7. rough make it rou2f
8. tough make it tou2f
9. enough make it enou2f
10. trough make it trou2f
11. gn make it 2n
12. If the name ends with
13. mb make it m2
14. Replace
15. cq with 2q
16. ci with si
17. ce with se
18. cy with sy
19. tch with 2ch
20. c with k
21. q with k
22. x with k
23. v with f
24. dg with 2g
25. tio with sio
26. tia with sia
27. d with t
28. ph with fh
29. b with p
30. sh with s2
31. z with s
32. an initial vowel{{notetag|Vowels are normally a, e, i, o, u but depending on the data might include characters such as æ, ā, or ø}} with an A
33. all other vowels with a 3
34. j with y
35. an initial y3 with Y3
36. an initial y with A
37. y with 3
38. 3gh3 with 3kh3
39. gh with 22
40. g with k
41. groups of the letter s with a S
42. groups of the letter t with a T
43. groups of the letter p with a P
44. groups of the letter k with a K
45. groups of the letter f with a F
46. groups of the letter m with a M
47. groups of the letter n with a N
48. w3 with W3
49. wh3 with Wh3
50. if the name ends in w replace the final w with 3
51. w with 2
52. an initial h with an A
53. all other occurrences of h with a 2
54. r3 with R3
55. if the name ends in r replace the final r with 3
56. r with 2
57. l3 with L3
58. if the name ends in l replace the final l with 3
59. l with 2
60. remove all 2s
61. if the name end in 3, replace the final 3 with A
62. remove all 3s
63. put ten 1s on the end
64. take the first ten characters as the code

----

{{notefoot}}

Lee -> lee
lee -> l33
l33 -> L33
L33 -> L
L -> L111111
L111111 -> L11111

Thompson -> thompson
thompson -> th3mps3n
th3mps3n -> th3mpS3n
th3mpS3n -> Th3mpS3n
Th3mpS3n -> Th3mPS3n
Th3mPS3n -> Th3MPS3n
Th3MPS3n -> Th3MPS3N
Th3MPS3N -> T23MPS3N
T23MPS3N ->  TMPSN
TMPSN111111 -> TMPSN1

Lee -> lee
lee -> le
le -> l3
l3 -> L3
L3 -> LA
LA -> LA1111111111
LA1111111111 -> LA11111111

Thompson -> thompson
thompson -> th3mps3n
th3mps3n -> th3mpS3n
th3mpS3n -> Th3mpS3n
Th3mpS3n -> Th3mPS3n
Th3mPS3n -> Th3MPS3n
Th3MPS3n -> Th3MPS3N
Th3MPS3N -> T23MPS3N
T23MPS3N ->  TMPSN
TMPSN1111111111 -> TMPSN11111

• Soundex
• New York State Identification and Intelligence System
• Match rating approach
• Metaphone
• Cologne phonetics

{{Reflist}}

• [http://caversham.otago.ac.nz/ Caversham Project] - Caversham data set of names and accents in the southern part of Dunedin, New Zealand in 1893-1938.
• [http://caversham.otago.ac.nz/files/working/ctp060902.pdf Original (2002) Caverphone algorithm]
• [http://caversham.otago.ac.nz/files/working/ctp150804.pdf Revised (2004) Caverphone algorithm]
• Implementations:
• [https://web.archive.org/web/20101216042037/http://sounditout.codeplex.com/ C# Revised Implementation]
• Java implementation in the [http://commons.apache.org/proper/commons-codec/ Apache Commons Codec] project
• [https://github.com/kiphughes/caverphone PHP implementation]
• Python Implementation [http://sourceforge.net/p/advas/code/ci/master/tree/advas-0.2.5/phonetics.py#l421 caverphone algorithm (version 2.0)] - AdvaS Advanced Search project

{{Authority control}}

Category:Phonetic algorithms