\nToday I was at a hardware store and noticed some ear protection rated as reducing noise by 27 decibels (aka 27 dB). What amount of noise dampening is that, really?<\/p>\n
\nDecibels measure a ratio of power between two sources. The formula is<\/p>\n
dB=10*log(S2\/S1), where S2 and S1 are the two sources.<\/p>\n
In this case, S2 is the dampened S1, and the formula reads<\/p>\n
-27=10*log(S2\/S1)<\/p>\n
which gives, by dividing both sides by 10,<\/p>\n
-2.7=log(S2\/S1)<\/p>\n
The log is base 10, so we have<\/p>\n
10^(-2.7)=S2\/S1<\/p>\n
which gives<\/p>\n
0.002=S2\/S1<\/p>\n
Therefore, a reduction of 27 dB dampens the noise to 0.002 times what it originally was.<\/p>\n
Interesting, eh?<\/p>\n
Source:<\/p>\n
courses.lumenlearning.com<\/a><\/p>\nJack of Oracle Tutoring by Jack and Diane,<\/a> Campbell River, BC.\n","protected":false},"excerpt":{"rendered":" Tutoring math, everyday situations come up. The tutor mentions a construction application: noise dampening. Today I was at a hardware store and noticed some ear protection rated as reducing noise by 27 decibels (aka 27 dB). What amount of noise …<\/p>\n