C
C
7 dB
B
A
C
A
C
A
72 dB
B
A
70 dB
C
A
B
A
B
A
C
B
A
C
70 dB
B
A
70 dB
B
C
72 dB
B
A
B
A
70 dB
B
A
70 dB
B
A
A
B
A
B
B
A
70 dB
B
A
A
B