<s>
Loudness	B-Algorithm
compensation	I-Algorithm
,	O
or	O
simply	O
loudness	B-Algorithm
,	O
is	O
a	O
setting	O
found	O
on	O
some	O
hi-fi	O
equipment	O
that	O
increases	O
the	O
level	O
of	O
the	O
high	O
and	O
low	O
frequencies	O
.	O
</s>
<s>
This	O
is	O
intended	O
to	O
be	O
used	O
while	O
listening	O
at	O
low-volume	O
levels	O
,	O
to	O
compensate	O
for	O
the	O
fact	O
that	O
as	O
the	O
loudness	B-Algorithm
of	O
audio	O
decreases	O
,	O
the	O
ear	O
's	O
lower	O
sensitivity	O
to	O
extreme	O
high	O
and	O
low	O
frequencies	O
may	O
cause	O
these	O
signals	O
to	O
fall	O
below	O
the	O
threshold	O
of	O
hearing	O
.	O
</s>
<s>
The	O
loudness	B-Algorithm
compensation	I-Algorithm
feature	O
applies	O
equalization	O
and	O
is	O
intended	O
to	O
rectify	O
this	O
situation	O
.	O
</s>
<s>
Correct	O
loudness	B-Algorithm
compensation	I-Algorithm
requires	O
a	O
calibrated	O
system	O
with	O
known	O
listening	O
level	O
.	O
</s>
<s>
For	O
loudness	B-Algorithm
compensation	I-Algorithm
to	O
work	O
correctly	O
the	O
playback	O
system	O
must	O
also	O
accurately	O
assume	O
what	O
volume	O
level	O
was	O
used	O
in	O
mastering	O
.	O
</s>
<s>
For	O
movie	O
soundtracks	O
this	O
reference	O
volume	O
level	O
is	O
an	O
industry	O
standard	O
and	O
can	O
be	O
used	O
by	O
manufacturers	O
to	O
provide	O
a	O
loudness	B-Algorithm
feature	O
that	O
works	O
with	O
a	O
reasonable	O
degree	O
of	O
accuracy	O
.	O
</s>
