<s>
Articulatory	B-Application
synthesis	I-Application
refers	O
to	O
computational	O
techniques	O
for	O
synthesizing	B-Application
speech	I-Application
based	O
on	O
models	O
of	O
the	O
human	O
vocal	O
tract	O
and	O
the	O
articulation	O
processes	O
occurring	O
there	O
.	O
</s>
<s>
However	O
,	O
historically	O
confirmed	O
speech	B-Application
synthesis	I-Application
begins	O
with	O
Wolfgang	O
von	O
Kempelen	O
(	O
1734	O
–	O
1804	O
)	O
,	O
who	O
published	O
an	O
account	O
of	O
his	O
research	O
in	O
1791	O
(	O
see	O
also	O
)	O
.	O
</s>
<s>
Recent	O
progress	O
in	O
speech	O
production	O
imaging	O
,	O
articulatory	O
control	O
modeling	O
,	O
and	O
tongue	O
biomechanics	O
modeling	O
has	O
led	O
to	O
changes	O
in	O
the	O
way	O
articulatory	B-Application
synthesis	I-Application
is	O
performed	O
.	O
</s>
<s>
Examples	O
include	O
the	O
Haskins	O
CASY	O
model	O
(	O
Configurable	O
Articulatory	B-Application
Synthesis	I-Application
)	O
,	O
designed	O
by	O
Philip	O
Rubin	O
,	O
Mark	O
Tiede	O
,	O
and	O
Louis	O
Goldstein	O
,	O
which	O
matches	O
midsagittal	O
vocal	O
tracts	O
to	O
actual	O
magnetic	O
resonance	O
imaging	O
(	O
MRI	O
)	O
data	O
,	O
and	O
uses	O
MRI	O
data	O
to	O
construct	O
a	O
3D	O
model	O
of	O
the	O
vocal	O
tract	O
.	O
</s>
<s>
A	O
full	O
3D	O
articulatory	B-Application
synthesis	I-Application
model	O
has	O
been	O
described	O
by	O
Olov	O
Engwall	O
.	O
</s>
<s>
A	O
geometrically	O
based	O
3D	O
articulatory	O
speech	B-Application
synthesizer	I-Application
has	O
been	O
developed	O
by	O
Peter	O
Birkholz	O
(	O
VocalTractLab	O
)	O
.	O
</s>
<s>
One	O
of	O
the	O
few	O
commercial	O
articulatory	O
speech	B-Application
synthesis	I-Application
systems	O
is	O
the	O
NeXT-based	O
system	O
originally	O
developed	O
and	O
marketed	O
by	O
Trillium	O
Sound	O
Research	O
,	O
a	O
spin-off	O
company	O
of	O
the	O
University	O
of	O
Calgary	O
,	O
where	O
much	O
of	O
the	O
original	O
research	O
was	O
conducted	O
.	O
</s>
<s>
Following	O
the	O
demise	O
of	O
the	O
various	O
incarnations	O
of	O
NeXT	O
(	O
started	O
by	O
Steve	O
Jobs	O
in	O
the	O
late	O
1980s	O
and	O
merged	O
with	O
Apple	O
Computer	O
in	O
1997	O
)	O
,	O
the	O
Trillium	O
software	O
was	O
published	O
under	O
a	O
GNU	B-License
General	I-License
Public	I-License
Licence	I-License
,	O
with	O
work	O
continuing	O
as	O
gnuspeech	B-Operating_System
.	O
</s>
<s>
The	O
system	O
,	O
first	O
marketed	O
in	O
1994	O
,	O
provides	O
full	O
articulatory-based	O
text-to-speech	B-Application
conversion	O
using	O
a	O
waveguide	O
or	O
transmission-line	O
analog	O
of	O
the	O
human	O
oral	O
and	O
nasal	O
tracts	O
controlled	O
by	O
Rene	O
Carré	O
's	O
"	O
distinctive	O
region	O
model	O
"	O
.	O
</s>
