<s>
A	O
voice	B-Protocol
browser	I-Protocol
is	O
a	O
software	B-Application
application	I-Application
that	O
presents	O
an	O
interactive	O
voice	B-Application
user	I-Application
interface	I-Application
to	O
the	O
user	O
in	O
a	O
manner	O
analogous	O
to	O
the	O
functioning	O
of	O
a	O
web	B-Application
browser	I-Application
interpreting	O
Hypertext	B-Language
Markup	I-Language
Language	I-Language
(	O
HTML	B-Language
)	O
.	O
</s>
<s>
Dialog	O
documents	O
interpreted	O
by	O
voice	B-Protocol
browser	I-Protocol
are	O
often	O
encoded	O
in	O
standards-based	O
markup	O
languages	O
,	O
such	O
as	O
Voice	B-Application
Dialog	I-Application
Extensible	I-Application
Markup	I-Application
Language	I-Application
(	O
VoiceXML	B-Application
)	O
,	O
a	O
standard	O
by	O
the	O
World	O
Wide	O
Web	O
Consortium	O
.	O
</s>
<s>
A	O
voice	B-Protocol
browser	I-Protocol
presents	O
information	O
aurally	O
,	O
using	O
pre-recorded	O
audio	O
file	O
playback	O
or	O
text-to-speech	B-Application
synthesis	O
software	O
.	O
</s>
<s>
A	O
voice	B-Protocol
browser	I-Protocol
obtains	O
information	O
using	O
speech	B-Application
recognition	I-Application
and	O
keypad	O
entry	O
,	O
such	O
as	O
DTMF	O
detection	O
.	O
</s>
<s>
As	O
speech	B-Application
recognition	I-Application
and	O
web	O
technologies	O
have	O
matured	O
,	O
voice	O
applications	O
are	O
deployed	O
commercially	O
in	O
many	O
industries	O
and	O
voice	B-Protocol
browsers	I-Protocol
are	O
supplanting	O
traditional	O
proprietary	O
interactive	O
voice	O
response	O
(	O
IVR	O
)	O
systems	O
.	O
</s>
<s>
Voice	B-Protocol
browser	I-Protocol
software	O
is	O
delivered	O
in	O
a	O
variety	O
of	O
implementations	O
models	O
.	O
</s>
<s>
Systems	O
that	O
present	O
a	O
voice	B-Protocol
browser	I-Protocol
to	O
a	O
user	O
,	O
typically	O
provide	O
interfaces	O
to	O
the	O
public	O
switched	O
telephone	O
network	O
or	O
to	O
a	O
private	B-Device
branch	I-Device
exchange	I-Device
.	O
</s>
