Prof Keith Attenborough and Dr Shahram Taherzadeh (OU)
Noise barriers are a common method of combating noise (mentioned under ‘environment’ in the KESS hot topics list) but they may be unsightly and tend to divide communities because any gaps affect their efficiency. The presentation will describe alternative methods based on the results of the Open University led parts of an EC FP7 project (HOSANNA www.greener-cities.eu). These methods are not considered at present by planners, highway engineers or noise consultants but are particularly relevant to cost-effective sustainable environmental policies in predominantly rural areas (common in Northern Ireland) and in cities, since they exploit and enhance the environment between the noise source and nearby people. They include (i) deployment of acoustically-soft ground such as non-compacted grassland; (ii) growing crops; (iii) planting tree belts and forests and (iv) deliberately introducing low (0.3 m high or less) wall configurations over hard ground. Tree belts can be effective noise barriers by combining sound absorption by decaying leaf litter, foliage attenuation and ‘sonic crystal’ effects through planting patterns. A particularly effective form of low wall design is a lattice. MLAs would benefit from knowing about these possibilities when making policies affecting land use and the planning of new developments near surface transport corridors.