9k
12
k
O
c
t
a
v
e
B
a
n
d
S
o
u
n
d
P
r
e
s
s
u
r
e
L
e
v
e
l
/
d
B
(
0
d
B
=
0
.
0
0
0
2
μ
b
a
r
)
8
0
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
Cooling
Hea
ting
NC-7
0
NC-6
0
NC-5
0
NC-4
0
NC-3
0
O
c
t
a
v
e
B
a
n
d
S
o
u
n
d
P
r
e
s
s
u
r
e
L
e
v
e
l
/
d
B
(
0
d
B
=
0
.
0
0
0
2
μ
b
a
r
)
80
70
60
50
40
30
20
10
0
Cooling
Hea
ting
NC-7
0
NC-6
0
NC-5
0
NC-4
0
NC-3
0
63
125
250
500
1000
2000
4000
800
0
Band Center Frequency /Hz
63
125
250
500
1000
2000
4000
800
0
Band Center Frequency /Hz
18k
24k
O
c
t
a
v
e
B
a
n
d
S
o
u
n
d
P
r
e
s
s
u
r
e
L
e
v
e
l
/
d
B
(
0
d
B
=
0
.
0
0
0
2
μ
b
a
r
)
80
70
60
50
40
30
20
10
0
Cooling
Hea
tin
g
NC-7
0
NC-60
NC-5
0
NC-40
NC-30
O
c
t
a
v
e
B
a
n
d
S
o
u
n
d
P
r
e
s
s
u
r
e
L
e
v
e
l
/
d
B
(
0
d
B
=
0
.
0
0
0
2
μ
b
a
r
)
80
70
60
50
40
30
20
10
0
Cooling
Hea
ting
NC-7
0
NC-6
0
NC-5
0
NC-4
0
NC-3
0
63
125
250
500
1000
2000
4000
8000
Band Center Frequency /H
z
63
125
250
500
1000
2000
4000
800
0
Band Center Frequency /Hz
34