C
B
D
A
72 dB
C
C
6 dB
C
B
D
A
72 dB
B
B
7 dB
B
A
B
A
D
B
7 dB
A
B
68 dB
C
B
70 dB
C
A
72 dB
B
A
70 dB
A
B
71 dB
A
B
C
C
B
A
7 dB
C
B
C
A
7 dB