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