Determination of noise source heights, part II: Measurement of the equivalent source height of highway vehicles

• Published in: Journal of sound and vibration 1990-11, Vol.143 (1), p.39-50
• Main Authors: Glegg, S.A.L., Yoon, J.R.
• Format: Article
• Language: English
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/0022-460X(90)90566-I

This is the second of two companion papers which describe the measurement of the equivalent point source height on highway vehicles. The first paper describes the measurement method, and the second its application to highway vehicles. This paper discusses the measurements on moving highway vehicles. First it is shown how the measurement method is suitable for measuring the equivalent point source height for application to noise barrier design. The measurement of noise source height on 36 heavy trucks, 37 medium vehicles and 25 small vehicles are then described. The results give the equivalent point source height as a function of frequency for each type of vehicle and identify the contributions of engine noise and tire noise. The measured source height was found to be ∼ 1·2 m for heavy vehicles, ∼0·7 m for medium vehicles and ∼0·6 m for small vehicles. These heights are significantly different from those currently used to design noise barriers, and suggest that further work should be undertaken to assess the implications of these results.