<s>
Chinese	B-Application
speech	I-Application
synthesis	I-Application
is	O
the	O
application	O
of	O
speech	B-Application
synthesis	I-Application
to	O
the	O
Chinese	O
language	O
(	O
usually	O
Standard	O
Chinese	O
)	O
.	O
</s>
<s>
It	O
poses	O
additional	O
difficulties	O
due	O
to	O
the	O
Chinese	O
characters	O
(	O
which	O
frequently	O
have	O
different	O
pronunciations	O
in	O
different	O
contexts	O
)	O
,	O
the	O
complex	O
prosody	O
,	O
which	O
is	O
essential	O
to	O
convey	O
the	O
meaning	O
of	O
words	O
,	O
and	O
sometimes	O
the	O
difficulty	O
in	O
obtaining	O
agreement	O
among	O
native	O
speakers	O
concerning	O
what	O
the	O
correct	O
pronunciation	O
is	O
of	O
certain	O
phonemes	B-Language
.	O
</s>
<s>
Recordings	O
can	O
be	O
concatenated	O
in	O
any	O
desired	O
combination	O
,	O
but	O
the	O
joins	O
sound	O
forced	O
(	O
as	O
is	O
usual	O
for	O
simple	O
concatenation-based	O
speech	B-Application
synthesis	I-Application
)	O
and	O
this	O
can	O
severely	O
affect	O
prosody	O
;	O
these	O
synthesizers	O
are	O
also	O
inflexible	O
in	O
terms	O
of	O
speed	O
and	O
expression	O
.	O
</s>
<s>
Some	O
of	O
the	O
Mandarin	O
syllables	O
have	O
been	O
pitched-normalised	O
in	O
Praat	B-Language
.	O
</s>
<s>
The	O
lightweight	O
open-source	O
speech	O
project	O
eSpeak	B-Language
,	O
which	O
has	O
its	O
own	O
approach	O
to	O
synthesis	O
,	O
has	O
experimented	O
with	O
Mandarin	O
and	O
Cantonese	O
.	O
</s>
<s>
eSpeak	B-Language
was	O
used	O
by	O
Google	B-Application
Translate	I-Application
from	O
May	O
2010	O
until	O
December	O
2010	O
.	O
</s>
<s>
The	O
commercial	O
product	O
"	O
Yuet	O
"	O
is	O
also	O
lightweight	O
(	O
it	O
is	O
intended	O
to	O
be	O
suitable	O
for	O
resource-constrained	O
environments	O
like	O
embedded	B-Architecture
systems	I-Architecture
)	O
;	O
it	O
was	O
written	O
from	O
scratch	O
in	O
ANSI	O
C	O
starting	O
from	O
2013	O
.	O
</s>
<s>
Yuet	O
claims	O
a	O
built-in	O
NLP	B-Language
model	O
that	O
does	O
not	O
require	O
a	O
separate	O
dictionary	O
;	O
the	O
speech	O
synthesised	O
by	O
the	O
engine	O
claims	O
clear	O
word	O
boundaries	O
and	O
emphasis	O
on	O
appropriate	O
words	O
.	O
</s>
<s>
Both	O
eSpeak	B-Language
and	O
Yuet	O
can	O
synthesis	O
speech	O
for	O
Cantonese	O
and	O
Mandarin	O
from	O
the	O
same	O
input	O
text	O
,	O
and	O
can	O
output	O
the	O
corresponding	O
romanisation	O
(	O
for	O
Cantonese	O
,	O
Yuet	O
uses	O
Yale	O
and	O
eSpeak	B-Language
uses	O
Jyutping	O
;	O
both	O
use	O
Pinyin	O
for	O
Mandarin	O
)	O
.	O
</s>
<s>
eSpeak	B-Language
does	O
not	O
concern	O
itself	O
with	O
word	O
boundaries	O
when	O
these	O
do	O
n't	O
change	O
the	O
question	O
of	O
which	O
syllable	O
should	O
be	O
spoken	O
.	O
</s>
<s>
Anhui	O
USTC	O
iFlyTek	O
Co.	O
,	O
Ltd	O
(	O
iFlyTek	O
)	O
published	O
a	O
W3C	O
paper	O
in	O
which	O
they	O
adapted	O
Speech	B-Application
Synthesis	I-Application
Markup	I-Application
Language	I-Application
to	O
produce	O
a	O
mark-up	O
language	O
called	O
Chinese	B-Application
Speech	B-Application
Synthesis	I-Application
Markup	I-Application
Language	I-Application
(	O
CSSML	O
)	O
which	O
can	O
include	O
additional	O
markup	O
to	O
clarify	O
the	O
pronunciation	O
of	O
characters	O
and	O
to	O
add	O
some	O
prosody	O
information	O
.	O
</s>
<s>
There	O
is	O
an	O
online	O
interactive	O
demonstration	O
for	O
NeoSpeech	B-Application
speech	B-Application
synthesis	I-Application
,	O
which	O
accepts	O
Chinese	O
characters	O
and	O
also	O
pinyin	O
if	O
it	O
's	O
enclosed	O
in	O
their	O
proprietary	O
"	O
VTML	O
"	O
markup	O
.	O
</s>
<s>
Mac	B-Application
OS	I-Application
had	O
Chinese	O
speech	B-Application
synthesizers	I-Application
available	O
up	O
to	O
version	O
9	O
.	O
</s>
<s>
Bell	O
Labs	O
 '	O
approach	O
,	O
which	O
was	O
demonstrated	O
online	O
in	O
1997	O
but	O
subsequently	O
removed	O
,	O
was	O
described	O
in	O
a	O
monograph	O
"	O
Multilingual	O
Text-to-Speech	B-Application
Synthesis	O
:	O
The	O
Bell	O
Labs	O
Approach	O
"	O
(	O
Springer	O
,	O
October	O
31	O
,	O
1997	O
,	O
)	O
,	O
and	O
the	O
former	O
employee	O
who	O
was	O
responsible	O
for	O
the	O
project	O
,	O
Chilin	O
Shih	O
(	O
who	O
subsequently	O
worked	O
at	O
the	O
University	O
of	O
Illinois	O
)	O
put	O
some	O
notes	O
about	O
her	O
methods	O
on	O
her	O
website	O
.	O
</s>
