SEARCH Articles Figures Tables A-4 gives the overall, A-weighted sound pressure levels and sound power levels for each machine, and the sound power levels of the motoiB. The total sound power levels of the machines agreed very well with the values obtained by the manufacturer using sound pressure measurements to derive the sound power levels . This technique can only give the total sound power of a machine it cannot obtain the sound power levels of parts of a machine. [Publishers Imprint]