During the past four decades, extensive research has been carried out on different noise barrier shapes using analytical and physical modelling as well as full scale testing. This paper reviews traffic noise barrier research and its findings to date. It provides a catalogue of noise barrier profiles; identifying the relative acoustic benefits of each and the physical principles on which they operate. The likely effects of ground and atmospheric conditions on their absolute acoustic performance are described. The types of barriers which are commonly used in practice and those deserving further attention are highlighted. Based on the findings of previous work, recommendations are made on possible areas of further research.

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This paper investigates the use of periodically spaced edges or wells for the control of road traffic noise. The wells have uniform height and width and are placed on the ground. Physical scale modeling is used to assess the acoustic performance of these structures under laboratory conditions. It is shown that, in certain situations where the use of conventional barriers would not be appropriate, strategically designed riblike structures can provide insertion losses of typically 10-15 dB. The findings are explained in terms of acoustic scattering with the approaches used in the study of resonators and diffraction/interference gratings.

The sound level difference of party walls at low frequencies [25–200 Hz] has been shown to be strongly dependent on the modal characteristics of the sound fields of the separated rooms. The modal characteristics can be modelled by numerical methods and a Finite Element Method has been selected to model sound transmission between adjacent rooms separated by a party wall. The numerical eigenfrequencies were compared with the theoretical eigenfrequencies to select a mesh model for which the eigenfrequencies are processed within an acceptable error range. As a prelude to the study of sound transmission between dwellings, the simulation of one single room, modelled with the selected mesh model, was validated by predicting the frequency response and comparing values with measured frequency response of a 1:4 scale room model. Results show promising agreement and establish the reliability of the work.

Traditional architecture has always demonstrated a strong relationship between the buildings and their environment, as these are designed with the climatic conditions and socio-cultural values in mind. However, multiple challenges facing traditional buildings are linked to the ability of communities to sustainably preserve themin an ever changing and very different urban fabric. At a time of great socio-economic change and technological progress, sustainability, both tangible and intangible, means preserving as much heritage as possible, would be an important factor in restoring and preserving the city’s identity. The traditional “ksour”settlements have proved their environmental and socio-cultural credentials. Given that this dwelling typology is fast disappearing and being replaced by villas and apartments using contemporary production methods and materials, this work aims to compare the two dwelling typologies with a view to test to what extent the latter ones do fulfil their environmental and socio-cultural roles and to identify what lessons, if any, can be learned from traditional settlements. The research presented here, which was undertaken using a qualitative approach based on case study analysis, is likely to contribute to a better understanding of the design and functioning of the“ksar”, which is a fast disappearing urban dwelling typology.