06 Part 2 Acoustical Rules of thumb and Demystifying the Decibel
By United Steel Structures Incorporated
When comparing decibel values, that best way to think about it is to consider how decibel values combine. For example, the combination of a sound having a level of 50 dB, and a second sound having an equal sound level of 50 dB is 53 dB. In shorthand (but not arithmetically correct) 50 dB, quote-unquote, plus 50 dB is 53 dB. This gives us a good rule of thumb to live by: Two equal sound levels combine to be 3 decibels greater than the individual. 65 dB "+" 65 dB = 68 dB When two sound levels differ by 10 decibels or more, when combined, the lesser level can be ignored. 65 dB + 75 dB = 75 dB Learn more about our company at www.ussi.com. We want to hear from you so please send us your questions at firstname.lastname@example.org.