Ex. F <br />Sean Malone <br />259 E Fifth Ave #200G <br />Eugene OR 97401 5/26/2015 <br />RE: Cingular Wireless at Crossfire Church (CU 14-3) <br />A revised noise study dated May 8, 2015 was submitted by SSA in support of the crossfire Church Cell <br />rd <br />tower project. It replaces the report dated Oct 22, 2014. The first and 3 pages remain unchanged while <br />ndth <br />the 2 and 4 pages were changed. The change involves only the noise from the generator room. <br />1)On page 2, an acoustically lined sheet metal hood was added to the outside of the air discharge <br />opening of the generator room. Now, both the air inlet and outlet openings have metal hoods but <br />there was no explanation was given as to why this second hood was added. <br />2)There is however, another change found on page 2, also involving the generator noise. The <br />exhaust pipe of the generator was specified to have a high performance muffler installed, GT <br />201-5100. The attenuation rating was initially specified to be in the range of 25 to 40 dBA but in <br />the present revision, the attenuation rating was raised to be in the range of 30 to 40 dBA. <br />improved by -5 dBA, from -30 dBA to -35 dBA. <br />A) Noise Sources <br />On Page 4 we find the predicted noise levels due to the operation of the generator. The net effect of <br />these changes is to reduce the predicted noise impact on nearby homes, to the west and to the south <br />caused by the generator. To the west the predicted generator noise impact is reduced from 46 dBA to <br />42 dBA and to the south, from 46 dBA to 45 dBA. <br />1) Exhaust Noise Reduction <br />The muffler attenuation was raised 5 dB in this revised report from 30 to 35 dBA. This caused the <br />predicted exhaust noise at the property to the west to be lowered from 45 dBA down to 40 dBA. It also <br />caused the predicted exhaust noise at the property to the south to be lowered from 36 down to 31 dBA. <br />To the West: Noise Control attenuation is raised from -30 dBA to -35 dBA <br />Resulting noise impact decreases from 45 to 40 dBA. <br />To the South: Noise Control attenuation is raised from -30 to -35 dBA <br /> Resulting noise impact increases from 36 dBA to 31 dBA <br />