News
If any news item relates to the acoustic consulting services you may require, please email news@aad.co.uk.
Listening to Dunes
The French national research agency, CNRS, recently shipped in sand from Morocco to find out how it is that desert avalanches can be tuneful. Although they managed to get some notes by pushing some types of sand, it lost its ability to sing after around a month of being pushed around. They reason that tuneful sand has a smooth layer of silicon, iron and manganese that probably formed when the dunes were under an ocean. As the muted grains had this layer worn away, this appears to explain why only some dunes can sing. They now postulate that during an avalanche, grains jostle each other setting up acoustic emissions within the cascading layer arising from standing waves that make the moving layer vibrate rather like a loudspeaker.
Apparently, the top 20 to 30mm is the depth of the resonating sand that causes other mobile grains to vibrate in step. By adjusting sand quantity and velocity, CNRS have generated different notes (a CD is being made) and now, although researchers in Chile and Stuttgart are onto the same theme, there is plenty more research left to understand more about sand tune riddles.
New Supersonic Airliner
New Scientist, September 2005
On 14th June 2005, Japan and France signed a three year agreement to jointly develop a new commercial supersonic jet, including the development of lightweight composite materials. It's not thought to be a Nissan-Renault project. Meanwhile, Japan is scheduled to perform aerodynamic testing of an unmanned prototype in Australia in September 2005 by strapping a mock up to a rocket. In case you thought that only UK and USA manufacture high thrust gas turbine engines, Japan has already tested a high-speed engine to mach 5.5 with success. The aircraft project targets very low weight and drag with 300 seats and a New York / Tokyo sector time of 6 hrs. The project includes research into sonic boom noise reduction whilst NASA has recently awarded four $1.0m projects to four industry teams to also research lower noise sonic booms.
80 year old widow locked up after making a noise complaint personally
Information from The Times, July 2005
Gwen Townsend, a retired accountant suffering from a heart condition, put up with two hours of "horrendous" drumming noise from a nearby community centre before she complained to the drummer personally. Gwen did not know that the band's drummer was an off duty police constable. She says that her approach, on being ignored, was to take a drumstick from him and bang his drum with it. The drummer, however, alleged she hit him with the stick and called the police. Either way, Gwen's complaint was ignored. She was arrested for ABH and she was then fingerprinted, DNA swabbed and locked in a cell at Melksham Police Station for 2 hours after which she was released on police bail and ordered to return to the police station in August.
Noise mapping could get more expensive
Information from Noise Management, July 2005
The UK, having been named and shamed by the European Commission, faces legal action because of delays in awarding noise mapping contracts. The EU’s objective is to substantially reduce the number of people in Europe affected by noise by 2012.
Substantial fine for making too much noise
Information from Noise Management, July 2005
Despite launching a defence that included making £22,000 worth of improvements to mitigate noise, Dudley Council succeeded in prosecuting a Stourbridge company at Halesowen Magistrates’ Court for failing to comply with a noise abatement notice served during February 2004. The company was fined £10,000 plus £830 costs.
Acoustic advice ignored
Information from Building, May 2005
BRE recommended that a 55 L nT,w dB impact noise level criterion was suitable for a high density residential development at Greenwich Millennium Village. This performance improvement represents a more onerous construction that is otherwise necessary to meet the minimum standard imposed by Approved Document E. On commissioning their own tests, however, residents found the as built performance failed to meet even the minimum standard required by the Regulations.
Acoustics regulations cost hikes threaten school projects
Information from Leader - QS Week, May 2005
The recently (well, July 2003) updated Approved Document E gets it in the neck from QS week, which headlines a south London schools project being subject to a 6% increase in overall cost because of the acoustic control requirements imposed by ADE. The thrust of the leader is that 6% is more than the 1.2% otherwise allowed, which they say is not consistent with building schools in urban locations.
From our experience, it’s often our fees and then the acoustic control that gets it in the neck “because of budget” so perhaps July 2003 was actually the date from which our design team colleagues became obliged to allocate acoustic design and construction funds on a more robustly informed basis. Allocating costs without properly considering acoustic matters at a sufficiently early stage on any project really should be a thing of the past; from our standpoint doing otherwise is a pretty pathetic – and potentially negligent - enterprise.
Noise outside schools hurts academic performance
Information from New Scientist, May 2005
According to South Bank University’s Bridget Shield, the higher the noise levels outside schools, the lower the scores. This conclusion was drawn from her team’s measurement of noise outside some 142 London primary schools when compared with results from national standard examination papers taken by pupils aged 7 to 11 years. The researchers conclude that schools should be located away from loud traffic if possible or to insulate or redesign existing school buildings.
Elephant articulates lorry
Information from Guardian, March 2005
Dr Joyce Pool, working with an elephant research project in Kenya, has found a 10 year old female elephant making sounds like distant trucks thundering along the Nairobi-Mambassa highway. “I think the elephant makes the sounds to relieve the boredom of being locked up all night”, says Dr Pool, who confirmed that she otherwise talks to other elephants and her keepers like a normal elephant!