<s>
Residual-excited	B-Algorithm
linear	I-Algorithm
prediction	I-Algorithm
(	O
RELP	O
)	O
is	O
an	O
obsolete	O
speech	B-Application
coding	I-Application
algorithm	O
.	O
</s>
<s>
It	O
was	O
originally	O
proposed	O
in	O
the	O
1970s	O
and	O
can	O
be	O
seen	O
as	O
an	O
ancestor	O
of	O
code-excited	B-Algorithm
linear	I-Algorithm
prediction	I-Algorithm
(	O
CELP	B-Algorithm
)	O
.	O
</s>
<s>
Unlike	O
CELP	B-Algorithm
however	O
,	O
RELP	O
directly	O
transmits	O
the	O
residual	O
signal	O
.	O
</s>
<s>
It	O
is	O
still	O
used	O
in	O
some	O
text-to-speech	O
voices	O
,	O
such	O
as	O
the	O
diphone	O
databases	O
found	O
in	O
the	O
Festival	B-Language
and	O
Flite	B-Language
speech	O
synthesizers	O
.	O
</s>
