Have you ever been irritated by a noisy washing machine? You know the situation: you put that last load of washing on for the evening, and head for bed. However, about 40 minutes later the machine has reached the spin cycle and all the clothes somehow end up bunched up on one side. The machine is humming and vibrating and appears to be seconds away from up and walking away across the floor…

This is a problem washing machine manufactures are all too aware of – the noise a washing machine produces may make all the difference in very competitive international market. AES, in conjunction with the Acoustic Research Group at the University of Canterbury, were engaged to undertake an extensive research and development project to develop a quieter machine.

This work had to start at the very core of the problem, looking in detail at the noise sources in the machine, and how this noise was transmitted to the listener. Through extensive experimental testing and analytical and numerical analysis, the noise produced by each source within the machine was quantified, and an understanding gained for how this noise travels to the listener.

Using this understanding, recommendations were made as to the most effective modifications for current machines, and a design guide produced to allow the potential noise from future machines to be assessed early in the design phase.

As a result of this work, methods for reducing the noise output of current washing machines by up to 50 % were identified. With this level of noise reduction, the machines are now quieter than even more highly-priced competitor models.