Minneapolis, Minnesota NOISE-CON 2005 2005 October 17-19 Prediction of Psychoacoustic Parameters Klaus Genuit André Fiebig HEAD acoustics GmbH HEAD acoustics GmbH Ebertstrasse 30a Ebertstrasse 30a 52134Herzogenrath 52134 Herzogenrath Germany Germany klaus.genuit@head-acoustics.de ABSTRACT Noise is defined as an audible sound which either disturbs the silence or an intentional sound listening or leads to annoyance. Thus, it is clearly defined that an assignment of noise can not be reduced to simple determining objective parameters like the A-weighted SPL. The question whether a sound is judged as noise can only be made after the transformation from the sound event into an hearing event has been accomplished. The evaluation of noise depends on the physical characteristics of the sound event, on the psychoacoustical features of the human ear as well as on the psychological aspects of men. The subjectively felt noise quality does not only depend on the A-weighted sound pressure level, but also on other psychoacoustical parameters such as loudness, roughness, sharpness, etc. The known methods for the prediction of the spatial A-weighted SPL distribution in dependence on the propagation are not suitable to predict psychoacoustic parameters in an adequate way. Especially the roughness provoked by modulation or the sharpness generated by an accumulation of high frequent sound energy cannot offhanded be predicted distance-dependent. 1. INTRODUCTION Our daily life experience may suggest that perception is simple and automatic, but it isn´t. We are so familiar with the act of perceiving that the complexity of the process emerges only when we deliberately turn our perceptual talents back on themselves to observe what is going on as we see, hear, smell, taste and touch the world. Perception of the everyday world is an exceedingly complicated phenomenon 1 . Particularly, sound is omnipresent in the perceptual world. Thus, this sensory dimension influences greatly the quality of life, since apart from the omnipresence of sound the human ear cannot be easily switched off in order to avoid acoustic input. Although sound can be analyzed and measured in physical terms and numbers, the complete analysis of sound depends on the psychoacoustic attributes of human hearing. For example, an assignment of noise can only be retraced with the help of a multidimensional approach, which takes into consideration the physical aspects of the sound, the frequency composition, psychoacoustic parameters (loudness, sharpness, roughness, fluctuation strength) as well as the attitude of the listener, the informative character of the sound, and the cultural background. Noisiness and annoyance are more (than energy of sound) sensitive to subjectivity, thus the social and cultural backgrounds have important influence on the subjective attitudes of people to the noise 2 . This means that the evaluation of noise depends on the physical characteristics of the sound event, on the psycho-acoustical features of the human ear as well as on the psychological and social aspects of human being.