18"

A B 71 dB

B A 71 dB

C C 71 dB

B A 70 dB

C C 73 dB

C B 72 dB

C A 70 dB

A A 71 dB

B A 69 dB

B B 69 dB

B B 67 dB

C A 70 dB

C C 72 dB

D C 72 dB

B A 71 dB

B B 69 dB

A B 72 dB

A B 69 dB

B B 72 dB

A B 70 dB

B A 70 dB

A A 70 dB

D B 71 dB