Application of cepstrum techniques and a guard tube to the measurement of the normal incident sound power absorption coefficient of road surfaces in-situ

The work described in this thesis was directed towards studying signal processing techniques that could best be incorporated in an apparatus that was to measure the plane wave sound power absorption coefficient of road surfaces in-situ. Road traffic noise has been identified as the greatest noise pollutant in the industrialised world with the tyre/road interaction being the major source of noise for traffic speeds in excess of 50 km/hr. Open pore bitumen asphalt material has been found to present a sound absorbing surface that is able to contribute to the mitigation of road traffic noise. This has generated research into the production of sound absorbing road surface materials which, in turn, has generated a need for an apparatus that is able to measure the sound power absorption coefficient of such materials both in the laboratory and in the field. It was considered that the development of an easily transportable apparatus was needed which would enable a single, non-skilled operator to measure rapidly the normal incident sound power absorption coefficient, over a broad frequency band, of road surfaces, in-situ. This included, for example, the measurement of the absorption coefficient of open-pore asphalt materials developed in the laboratory, the measurement of newly laid surfaces, the comparison of different surfaces, as well as determining the effect of contamination, over time, of the pores of open-pore asphalt by ingress of dust.

Grantor dc:publisher.institution

Department of Electrical Engineering

Year dc:date.issued

1993

Author dc:creator

• Jongens, Adrian Wynand Doride

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/9639

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/9639