Different noise values according to producers‘ declarations depends on the
measurement standard that has been used and can lead to misunderstandings.
Generally noise levels are measured as Sound Power (LwA) according IEC 60704-3
and presented in Decibels (dBA). Sound Power is an absolute measurement of noise
level and is what is generated by the vacuum cleaner. It is independent of environment
and gives a more accurate representation of the power of a vacuum cleaner to produce
noise. As the decibel scale is logarithmic, an increase of 3dB means that the sound
power is doubled. However a difference of 3dB is the smallest difference that is
normally audible to the human ear.
The eco-label criteria for vacuum cleaners [8] which has not yet come into force
included criteria for noise,