The effect of traffic flows on urban soundscape dynamics and how to analyze it

Subjective evaluation of soundscapes considers without a doubt the change in amplitude and frequency of the acoustic signal over time. The urban environment can make these soundscape dynamics become rather complex and interesting. In this paper we investigate how traffic flows, quite often the main source of noise in urban an suburban environments, influence the dynamics of the soundscape at intervals of the order of a few seconds to minutes. A model for dynamical traffic noise prediction is presented. Novel descriptors based on the power spectrum of noise level fluctuations allow us to show, using static maps, how the dynamics evolve in side streets, on squares etc

1/f dynamics in the urban soundscape

Urban soundscapes are characterized by much more than loudness alone. Subjective description has been used by many researchers to grasp these additional dimensions, but very little objective criteria are found in literature. In this paper the dynamics of the soundscape is proposed as a potential indicator. By analyzing loudness and pitch fluctuations in longer sound fragments recorded in urban environment, 1/f spectral behavior at frequencies ranging from 0.01 to 10 Hz was discovered. Such behavior is typical for complex systems and was found to be very common in (classical) music, already in the seventies. Some hypotheses will be given on the origin of this frequency dependence of urban‐soundscape dynamics. The possibility of discriminating soundscapes on the basis of the frequency dependence of loudness and pitch fluctuation will be illustrated. For this purpose the urban soundscapes are compared to "extreme" soundscapes that have a very distinct character that is clear to every observer

An LAeq is not an LAeq

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