Georgina Bisby explores the findings of a new report which suggests that the noise from some super-fast hand dryers is causing "unwelcome stress" to society's most vulnerable
After a maternity leave spent dodging washrooms with loud hand dryers, the release of some research from Goldsmiths, University of London which suggests that super-fast hand dryers have a negative impact on the vulnerable came as little surprise.
According to the research the noise from some high-speed hand dryers has the same impact on the human ear as that of a road drill at close range and can cause serious discomfort to vulnerable members of society.
Led by Dr John Levack Drever, Senior Lecturer in Composition and Head of the Unit for Sound Practice Research at Goldsmiths, the research project consisted of a range of studies including product acoustic testing, environmental acoustics and noise assessment, and interviews with members of the public.
Studies undertaken in toilets and in spaces resembling the typical box shape of a public toilet, found that the decibels reached by hand dryers could reach 11 times more than that recorded in the product-testing lab, which in some cases was in contrast to the advertised sound levels of the hand dryers.
People who reported that they had been negatively affected include: elderly dementia sufferers, visually impaired people struggling with navigation, hearing aid users forced to turn off their auditory devices as they enter the toilets and those with hyperacute hearing – a condition characterised by an oversensitivity to certain frequency ranges of sound and common for those on the autistic spectrum. Mothers also reported a reluctance to use dedicated breast-feeding or baby changing provisions located near hand dryers due to the loud noise affecting both themselves and their infants.
Response from manufacturers
Hand dryer manufacturers have been keen to draw attention to the progress that has been made in their efforts to reduce the noise levels of high-speed dryers as well as the complexities of measuring noise levels. Many high speed hand dryers have a reported operating level in excess of 85dB but in 2012 hand drying systems provider Airdri was the first in the high speed category to be awarded the Quiet Mark for its Classic+ MkII hand dryer which has a reported operating level of 72dB. The Quiet Mark is an international mark of approval from the UK Noise Abatement Society which encourages companies to prioritise noise reduction when developing machines and appliances used in everyday life.
Trudi Osborne, marketing communications manager of Airdri, suggests: "Architects and planners need to think about a range of social issues when specifying equipment, including noise and size of equipment for more accessible access. Airdri has listened carefully to our customer requirements and designed The Classic+ MkII, to reduce noise levels without reducing functionality."
The Jet Towel hand dryer from Mitsubishi Electric which has an operating sound level of 58dB has also recently been awarded the Quiet Mark. Mitsubishi Electric says this is part of its very long-term business development strategy, for which the company has adopted the mission statement: "Changes for the better” which sees them "strive to improve quality of life by developing products that are not only technically better than competitors’, but which are also designed to reduce users’ stress and have minimal impact on the environment."
A spokesperson for Dyson, manufacturer of the high-speed Airblade hand dryer, was critical of the report, suggesting that: "It is narrow in the sense it forgets sound is not simply about power - it is also about sound quality.
"At Dyson we challenge our engineers to improve both," explains the spokesperson, adding: "The report suggests that decibels are the most problematic thing to a user – actually it is often certain tones and frequencies which are most frustrating. The mosquito example is case in point. For this our hand dryers use Dyson designed and developed Helmholtz silencers which eliminate specific motor tones. Six chambers, each with a hole on the outside isolate and substantially reduce the first and fourth harmonic of the motor tone – the unpleasant frequencies most prominent to the human ear," they conclude. Dyson says it spends nearly £1.5m a year on acoustic research alone.
So while it seems there may be more to the issue of noise from high-speed hand dryers than first meets the ear, and high speed hand dryers vary greatly in their acoustic performance and are continually improving, current installations are causing a significant problem to many members of society.
Goldsmiths University says the next phase of this project will see the commissioning of a wide range of users to compose and in turn propose new favourable sound design possibilities. Dr Drever concludes: "From this initial study it is evident that 'ultra rapid' cold air hand dryers are loud, and this loudness is vastly amplified in the highly reverberant and reflective small toilet. To solve these issues, we propose that engineers, sound artists and users come together to look at the acoustic space in which these dryers are found and tune the products accordingly to enhance the listening experience and minimise the discomfort that is caused to a whole range of people."
Case Study: Flying start for Birmingham Airport passengers’ travel experience
Birmingham Airport welcomes nine million passengers through its terminal a year, with footfall set to increase as demand grows and thanks to a runway extension, which opens in early 2014. An increased length of 3,003 metres will enable aircraft to fly direct to many destinations currently out of reach.
First class washroom facilities are an important part of the passenger experience. As there are so many people passing through the airport, hand-drying equipment needs to be both reliable and durable, whilst being easy to service and cost effective.
Noise must be kept to a minimum to ensure that passengers and staff don’t miss vital security announcements. When Airdri launched its fast drying, energy efficient hand dryer, the Classic MKII, last year, it seemed a good fit, as it also has the lowest noise levels in its class. Airdri had previously supplied the airport with its durable ‘Tough One’, the Airdri Classic for over twelve years, and recommended its new product during a period of expansion for the airport.
The Classic MK II, which is said to have a lifespan six times longer than other fast dry hand dryers, was tested alongside other dryers used in the airport before being chosen as the dryer of choice. The product also has a reduced power consumption of 1.3kw @ 230 volts, improving energy efficiency.
Deane Arnold, contracts manager for Birmingham Airport, said: "The long life cycle of the dryer is an attractive proposition for us, but the real bonus is that the dryer is so energy efficient that it will have paid for itself within a twelve month period. The reduction in the noise level is a huge benefit too. If several dryers are in use simultaneously, alongside other products, this can be deafening. It’s something we’ve been waiting for manufacturers to address for some time.”
