20"

A A 70 dB

C B 72 dB

C C 72 dB

C C 73 dB

C A 71 dB

C B 72 dB

A D 70 dB

C C 72 dB

B A 72 dB

C B 71 dB

D C 74 dB

B D 71 dB

B A 71 dB

C C 71 dB

C C 74 dB

C B 70 dB

B C 73 dB

C C 70 dB

C A 70 dB

C C 71 dB

D C 72 dB