18"

A A 69 dB

B B 71 dB

C A 71 dB

A B 70 dB

A A 69 dB

B A 70 dB

C B 69 dB

C A 68 dB

B D 70 dB

C A 72 dB

B A 70 dB

A B 69 dB

B C 71 dB

B B 72 dB

B A 71 dB

B C 72 dB

D C 70 dB

C A 70 dB

C C 71 dB

D A 71 dB

D B 72 dB

B B 71 dB

B C 71 dB