<s>
Apparent	B-Application
source	I-Application
width	I-Application
(	O
ASW	O
)	O
is	O
the	O
audible	O
impression	O
of	O
a	O
spatially	O
extended	O
sound	O
source	O
.	O
</s>
<s>
Wide	O
sources	O
are	O
desired	O
by	O
listeners	O
of	O
music	O
because	O
these	O
are	O
associated	O
with	O
sound	O
of	O
acoustic	O
music	O
,	O
opera	B-Application
,	O
classical	O
music	O
,	O
historically	O
informed	O
performance	O
.	O
</s>
<s>
Research	O
concerning	O
ASW	O
comes	O
from	O
the	O
field	O
of	O
room	O
acoustics	O
,	O
architectural	O
acoustics	O
and	O
auralization	B-Application
as	O
well	O
as	O
musical	O
acoustics	O
,	O
psychoacoustics	O
and	O
systematic	O
musicology	O
.	O
</s>
<s>
Apparent	B-Application
source	I-Application
width	I-Application
is	O
the	O
aurally	O
perceived	O
extent	O
of	O
a	O
sound	O
source	O
.	O
</s>
<s>
Since	O
the	O
term	O
apparent	B-Application
source	I-Application
width	I-Application
has	O
been	O
used	O
a	O
lot	O
in	O
the	O
field	O
of	O
subjective	O
room	O
acoustics	O
to	O
characterize	O
how	O
the	O
room	O
affects	O
the	O
perception	O
of	O
source	O
size	O
,	O
the	O
term	O
perceived	O
source	O
extent	O
has	O
been	O
introduced	O
to	O
highlight	O
that	O
the	O
perception	O
results	O
from	O
both	O
the	O
sound	O
source	O
and	O
the	O
room	O
.	O
</s>
<s>
While	O
the	O
late	O
reverberation	O
contributes	O
to	O
the	O
perception	O
of	O
and	O
reverberance	O
,	O
the	O
direct	O
sound	O
and	O
the	O
early	O
reflections	O
mostly	O
affect	O
source	O
localization	O
,	O
intimacy	O
and	O
the	O
apparent	B-Application
source	I-Application
width	I-Application
.	O
</s>
<s>
The	O
process	O
of	O
integration	O
and	O
segregation	O
is	O
referred	O
to	O
as	O
auditory	B-Application
scene	I-Application
analysis	I-Application
and	O
is	O
believed	O
to	O
be	O
the	O
original	O
function	O
of	O
the	O
ear	O
.	O
</s>
<s>
Each	O
auditory	O
stream	O
can	O
have	O
its	O
own	O
apparent	B-Application
source	I-Application
width	I-Application
.	O
</s>
<s>
A	O
high	O
strength	O
of	O
low	O
frequencies	O
and	O
incoherence	O
of	O
the	O
left	O
and	O
the	O
right	O
ear	O
of	O
one	O
auditory	O
stream	O
,	O
especially	O
of	O
its	O
direct	O
sound	O
and	O
early	O
reflections	O
,	O
increase	O
the	O
apparent	B-Application
source	I-Application
width	I-Application
.	O
</s>
<s>
Rather	O
the	O
overall	O
volume	B-Application
and	O
the	O
frequency	O
spectrum	O
differ	O
in	O
each	O
direction	O
.	O
</s>
<s>
This	O
is	O
referred	O
to	O
as	O
sound	O
radiation	O
characteristics	O
or	O
radiation	B-Device
patterns	I-Device
.	O
</s>
<s>
The	O
sound	O
radiation	O
characteristics	O
of	O
musical	O
instruments	O
are	O
typically	O
given	O
as	O
radiation	B-Device
pattern	I-Device
in	O
a	O
two	O
-	O
to	O
three-dimensional	O
polar	O
coordinate	O
system	O
.	O
</s>
<s>
The	O
apparent	B-Application
source	I-Application
width	I-Application
and	O
other	O
subjective	O
sound	O
properties	O
in	O
many	O
concert	O
halls	O
have	O
been	O
rated	O
by	O
experts	O
,	O
including	O
conductors	O
and	O
music	O
critics	O
.	O
</s>
<s>
Together	O
,	O
apparent	B-Application
source	I-Application
width	I-Application
and	O
listener	O
envelopment	O
are	O
the	O
most	O
important	O
contributors	O
to	O
the	O
spaciousness	O
impression	O
of	O
a	O
concert	O
hall	O
which	O
is	O
the	O
most	O
important	O
contributor	O
to	O
the	O
quality	O
ratings	O
of	O
concert	O
halls	O
.	O
</s>
<s>
In	O
the	O
field	O
of	O
subjective	O
room	O
acoustics	O
the	O
sound	O
radiation	O
characteristics	O
are	O
ignored	O
and	O
the	O
apparent	B-Application
source	I-Application
width	I-Application
is	O
explained	O
by	O
means	O
of	O
objective	O
measures	O
of	O
room	O
impulse	O
responses	O
,	O
like	O
the	O
binaural	O
quality	O
index	O
,	O
the	O
lateral	O
energy	O
fraction	O
and	O
the	O
early	O
sound	O
strength	O
.	O
</s>
<s>
Accordingly	O
,	O
early	O
,	O
incoherent	O
,	O
lateral	O
reflections	O
together	O
with	O
a	O
high	O
loudness	B-Algorithm
of	O
low	O
frequencies	O
in	O
the	O
early	O
reflections	O
of	O
the	O
room	O
reverberation	O
increase	O
the	O
apparent	B-Application
source	I-Application
width	I-Application
and	O
thus	O
the	O
overall	O
spaciousness	O
and	O
quality	O
of	O
a	O
concert	O
hall	O
.	O
</s>
<s>
The	O
increase	O
of	O
apparent	B-Application
source	I-Application
width	I-Application
is	O
as	O
important	O
as	O
spectral	O
balancing	O
and	O
dynamic	O
range	O
compression	O
.	O
</s>
<s>
These	O
techniques	O
decorrelate	B-Algorithm
the	O
stereo	O
channels	O
by	O
applying	O
individual	O
audio	O
filters	O
,	O
reverberation	O
or	O
delay	O
effects	O
to	O
each	O
.	O
</s>
<s>
Several	O
subjective	O
sound	O
impressions	O
are	O
closely	O
related	O
to	O
apparent	B-Application
source	I-Application
width	I-Application
.	O
</s>
<s>
Liveness	B-Application
is	O
the	O
impression	O
that	O
the	O
room	O
contributes	O
more	O
than	O
just	O
repetitions	O
of	O
direct	O
sound	O
.	O
</s>
<s>
Spaciousness	O
is	O
a	O
term	O
that	O
summarizes	O
apparent	B-Application
source	I-Application
width	I-Application
and	O
listener	O
envelopment	O
.	O
</s>
