<s>
Metaphone	B-Algorithm
is	O
a	O
phonetic	B-Algorithm
algorithm	I-Algorithm
,	O
published	O
by	O
Lawrence	B-Algorithm
Philips	I-Algorithm
in	O
1990	O
,	O
for	O
indexing	O
words	O
by	O
their	O
English	O
pronunciation	O
.	O
</s>
<s>
It	O
fundamentally	O
improves	O
on	O
the	O
Soundex	B-Algorithm
algorithm	O
by	O
using	O
information	O
about	O
variations	O
and	O
inconsistencies	O
in	O
English	O
spelling	O
and	O
pronunciation	O
to	O
produce	O
a	O
more	O
accurate	O
encoding	O
,	O
which	O
does	O
a	O
better	O
job	O
of	O
matching	O
words	O
and	O
names	O
which	O
sound	O
similar	O
.	O
</s>
<s>
As	O
with	O
Soundex	B-Algorithm
,	O
similar-sounding	O
words	O
should	O
share	O
the	O
same	O
keys	O
.	O
</s>
<s>
Metaphone	B-Algorithm
is	O
available	O
as	O
a	O
built-in	O
operator	O
in	O
a	O
number	O
of	O
systems	O
.	O
</s>
<s>
Philips	O
later	O
produced	O
a	O
new	O
version	O
of	O
the	O
algorithm	O
,	O
which	O
he	O
named	O
Double	O
Metaphone	B-Algorithm
.	O
</s>
<s>
In	O
2009	O
Philips	O
released	O
a	O
third	O
version	O
,	O
called	O
Metaphone	B-Algorithm
3	O
,	O
which	O
achieves	O
an	O
accuracy	O
of	O
approximately	O
99%	O
for	O
English	O
words	O
,	O
non-English	O
words	O
familiar	O
to	O
Americans	O
,	O
and	O
first	O
names	O
and	O
family	O
names	O
commonly	O
found	O
in	O
the	O
United	O
States	O
,	O
having	O
been	O
developed	O
according	O
to	O
modern	O
engineering	O
standards	O
against	O
a	O
test	O
harness	O
of	O
prepared	O
correct	O
encodings	O
.	O
</s>
<s>
Original	O
Metaphone	B-Algorithm
codes	O
use	O
the	O
16	O
consonant	O
symbols	O
0BFHJKLMNPRSTWXY	O
.	O
</s>
<s>
The	O
'	O
0	O
 '	O
represents	O
"	O
th	O
"	O
(	O
as	O
an	O
ASCII	B-Protocol
approximation	O
of	O
Θ	O
)	O
,	O
'	O
X	O
 '	O
represents	O
"	O
sh	O
"	O
or	O
"	O
ch	O
"	O
,	O
and	O
the	O
others	O
represent	O
their	O
usual	O
English	O
pronunciations	O
.	O
</s>
<s>
This	O
table	O
does	O
not	O
constitute	O
a	O
complete	O
description	O
of	O
the	O
original	O
Metaphone	B-Algorithm
algorithm	O
,	O
and	O
the	O
algorithm	O
cannot	O
be	O
coded	O
correctly	O
from	O
it	O
.	O
</s>
<s>
Original	O
Metaphone	B-Algorithm
contained	O
many	O
errors	O
and	O
was	O
superseded	O
by	O
Double	O
Metaphone	B-Algorithm
,	O
and	O
in	O
turn	O
Double	O
Metaphone	B-Algorithm
and	O
original	O
Metaphone	B-Algorithm
were	O
superseded	O
by	O
Metaphone	B-Algorithm
3	O
,	O
which	O
corrects	O
thousands	O
of	O
miscodings	O
that	O
will	O
be	O
produced	O
by	O
the	O
first	O
two	O
versions	O
.	O
</s>
<s>
To	O
implement	O
Metaphone	B-Algorithm
without	O
purchasing	O
a	O
(	O
source	O
code	O
)	O
copy	O
of	O
Metaphone	B-Algorithm
3	O
,	O
the	O
reference	O
implementation	O
of	O
Double	O
Metaphone	B-Algorithm
can	O
be	O
used	O
.	O
</s>
<s>
Alternatively	O
,	O
version	O
2.1.3	O
of	O
Metaphone	B-Algorithm
3	O
,	O
an	O
earlier	O
2009	O
version	O
without	O
a	O
number	O
of	O
encoding	O
corrections	O
made	O
in	O
the	O
current	O
version	O
,	O
version	O
2.5.4	O
,	O
has	O
been	O
made	O
available	O
under	O
the	O
terms	O
of	O
the	O
BSD	B-Operating_System
License	I-Operating_System
via	O
the	O
OpenRefine	O
project	O
.	O
</s>
<s>
The	O
Double	O
Metaphone	B-Algorithm
phonetic	B-Algorithm
encoding	I-Algorithm
algorithm	O
is	O
the	O
second	O
generation	O
of	O
this	O
algorithm	O
.	O
</s>
<s>
It	O
makes	O
a	O
number	O
of	O
fundamental	O
design	O
improvements	O
over	O
the	O
original	O
Metaphone	B-Algorithm
algorithm	O
.	O
</s>
<s>
Double	O
Metaphone	B-Algorithm
tries	O
to	O
account	O
for	O
myriad	O
irregularities	O
in	O
English	O
of	O
Slavic	O
,	O
Germanic	O
,	O
Celtic	O
,	O
Greek	O
,	O
French	O
,	O
Italian	O
,	O
Spanish	O
,	O
Chinese	O
,	O
and	O
other	O
origins	O
.	O
</s>
<s>
A	O
professional	O
version	O
was	O
released	O
in	O
October	O
2009	O
,	O
developed	O
by	O
the	O
same	O
author	O
,	O
Lawrence	B-Algorithm
Philips	I-Algorithm
.	O
</s>
<s>
Metaphone	B-Algorithm
3	O
further	O
improves	O
phonetic	B-Algorithm
encoding	I-Algorithm
of	O
words	O
in	O
the	O
English	O
language	O
,	O
non-English	O
words	O
familiar	O
to	O
Americans	O
,	O
and	O
first	O
names	O
and	O
family	O
names	O
commonly	O
found	O
in	O
the	O
United	O
States	O
.	O
</s>
<s>
The	O
author	O
claims	O
that	O
in	O
general	O
it	O
improves	O
accuracy	O
for	O
all	O
words	O
from	O
the	O
approximately	O
89%	O
of	O
Double	O
Metaphone	B-Algorithm
to	O
98%	O
.	O
</s>
<s>
Developers	O
can	O
also	O
now	O
set	O
switches	O
in	O
code	O
to	O
cause	O
the	O
algorithm	O
to	O
encode	O
Metaphone	B-Algorithm
keys	O
1	O
)	O
taking	O
non-initial	O
vowels	O
into	O
account	O
,	O
as	O
well	O
as	O
2	O
)	O
encoding	O
voiced	O
and	O
unvoiced	O
consonants	O
differently	O
.	O
</s>
<s>
Metaphone	B-Algorithm
3	O
is	O
sold	O
as	O
C++	O
,	O
Java	O
,	O
C#	O
,	O
PHP	O
,	O
Perl	O
,	O
and	O
PL/SQL	O
source	O
,	O
Ruby	O
and	O
Python	O
wrappers	O
accessing	O
a	O
Java	O
jar	O
,	O
and	O
also	O
Metaphone	B-Algorithm
3	O
for	O
Spanish	O
and	O
German	O
pronunciation	O
available	O
as	O
Java	O
and	O
C#	O
source	O
.	O
</s>
<s>
The	O
latest	O
revision	O
of	O
the	O
Metaphone	B-Algorithm
3	O
algorithm	O
is	O
v2.5.4	O
,	O
released	O
March	O
2015	O
.	O
</s>
<s>
There	O
are	O
some	O
misconceptions	O
about	O
the	O
Metaphone	B-Algorithm
algorithms	O
that	O
should	O
be	O
addressed	O
.	O
</s>
<s>
Metaphone	B-Algorithm
algorithms	O
do	O
not	O
produce	O
phonetic	O
representations	O
of	O
the	O
input	O
words	O
and	O
names	O
;	O
rather	O
,	O
the	O
output	O
is	O
an	O
intentionally	O
approximate	O
phonetic	O
representation	O
,	O
according	O
to	O
this	O
standard	O
:	O
</s>
<s>
words	O
that	O
start	O
with	O
a	O
vowel	O
sound	O
will	O
have	O
an	O
'	O
A	O
 '	O
,	O
representing	O
any	O
vowel	O
,	O
as	O
the	O
first	O
character	O
of	O
the	O
encoding	O
(	O
in	O
Double	O
Metaphone	B-Algorithm
and	O
Metaphone	B-Algorithm
3	O
-	O
original	O
Metaphone	B-Algorithm
just	O
preserves	O
the	O
actual	O
vowel	O
)	O
,	O
</s>
<s>
Metaphone	B-Algorithm
is	O
useful	O
for	O
English	O
variants	O
and	O
other	O
languages	O
,	O
having	O
been	O
preferred	O
to	O
Soundex	B-Algorithm
in	O
several	O
Indo-European	O
languages	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
rough	O
phonetic	B-Algorithm
encoding	I-Algorithm
causes	O
language	O
dependency	O
or	O
,	O
in	O
a	O
language	O
variant	O
,	O
average	O
language-speaker	O
dependency	O
mainly	O
for	O
non-English	O
variants	O
.	O
</s>
<s>
Perhaps	O
the	O
first	O
example	O
of	O
stable	O
adaptation	O
of	O
non-English	O
metaphone	B-Algorithm
was	O
Brazilian	O
Portuguese	O
:	O
it	O
as	O
a	O
database	O
solution	O
in	O
Várzea	O
Paulista	O
municipality	O
of	O
Brazil	O
,	O
and	O
it	O
evolved	O
to	O
the	O
.	O
</s>
