20"

C A 71 dB

A B 70 dB

B C 71 dB

D B 74 dB

C C 71 dB

C A 70 dB

C B 72 dB

C D 71 dB

C A 71 dB

B A 70 dB

C B 71 dB

C B 71 dB

B A 72 dB

D B 69 dB

A B 70 dB

C C 74 dB

B A 72 dB

B B 72 dB

C A 71 dB

A A 73 dB

C B 72 dB