During the re-design exercise for a new model, the noise from this vacuum cleaner was not only reduced by a factor of 10 (10dB(A)), but the subjective character of the noise was also substantially changed by eliminating tonal components to make it sound “nicer” (a specialist technical term in acoustics!). The development process involved very detailed diagnostic analyses to rank the contributions from all the noise sources so that the optimum modifications could be designed. Consequently, the cost in the final new product of the designed-in noise reduction features was negligible.
The noise reduction programme result also had the side effect of making the vacuum cleaner sound more powerful…
