This graph has several vertical bars, which may at first be confusing, but the telling information is at the far right where it is marked "Average". This is the data that appears on the label attached to the blower. The ANSI Standard requires that the operator stand fifty feet from the microphone and then take eight measurements to be averaged for a final value. Each measurement is taken 45 degrees from the previous position as the operator rotates in place 360 degrees, hence the other bars on the graph.

This data shows the ECHO gasoline powered unit to average exactly 65 dB(A). The other units are all higher, with the Black & Decker unit (the one having the straight discharge pipe) being the loudest. This clearly shows that the "Quiet" gasoline powered leaf blower is more than comparable to electric when it comes to sound. It also shows how surprisingly loud an electric blower can be at about 74 dB(A).

It is important to note that sound is measured in Micro Pascal’s and then converted by the measuring device to a logarithmic value called decibels. An easy way to compare sound levels is to consider that for every 6 dB(A) change, the sound level measured in Micro Pascal’s either increases by a factor of 2 or decreases by half. In other words, 71 dB(A) is twice as loud as 65 and 77 dB(A) is twice as loud as 71. Seventy-seven dB(A) is therefore four times as loud as 65. In this comparison, 65 dB(A) represents a 75% reduction in sound from 77dB(A). A more detailed explanation is available on page 6 of the pamphlet found at the following link: http://leafblowernoise.com/Measuring_Sound.pdf

For the commercial operator, the quiet gasoline powered leaf blower will be preferred over electric because it has better performance and is not tied to a building or generator by an electric cord. Battery powered units are totally unacceptable because of their extremely low performance and serious lack of endurance.