Question

If you attend a rock concert wearing earplugs that provide a reduction of 13 dB, what is the ratio of the sound intensity reaching your eardrums to that just outside the earplugs? What percentage of the sound energy is getting through? What percentage is being blocked out? In order to achieve 23 dB reduction, what percentage would have to be blocked out?

Answer 1

here,

dB = 13 dB

Power in dB = 10 log (Power in / Power out)

13 = 10 * log ( Pi/Po)

pi/po = 19.95

the ratio of the sound intensity reaching your eardrums to that just outside the earplugs is 19.95 :1

percentage of the sound intensity reaching your eardrums to that just outside the earplugs , % = po/pi *100

% = 1/19.95 * 100

% = 5 %

percentage of the sound intensity reaching your eardrums to that just outside the earplugs is 5 %

the percentage is being blocked out , % = 100 - 5

% = 95 %

the percentage being blocked out is 95 %

dB = 23 dB

Power in dB = 10 log (Power in / Power out)

23 = 10 * log ( Pi/Po)

pi/po = 199.53

% being blocked out , % = 100 - (1/199.95 *100)

% = 99.5 %

percentage would have to be blocked out is 99.5 %