Ground-borne vibrations, sounds and secondary airborne sounds from tramways: a psychoacoustic evaluation including health aspects

For decades, urban noise and vibration studies were mostly concerned with road traffic and trains. Tramway noise was rarely studied. Since the introduction of new types of tramways in the city of Graz strong complaints were brought up by local residents in certain areas. Typically, the annoyance by tramways results from a complex combination of sounds and vibration exposure depending on ground structure and building conditions. To sufficiently account for this complexity an integrated psychoacoustic approach was applied. In a free field study ground-borne vibrations and sounds as well as secondary airborne sound recordings were carried out for various tramway types. For this purpose a binaural dummy head measurement system for noise and a triaxial accelerometer for vibrations were used to operate in synchrony. In addition to standard sound parameters (SPL), psychoacoustic parameters were analyzed to learn more about the complex psychological and physiological responses associated with the introduction of the new tramway types in Graz. First results indicate differences between the different tramway types in both classical and psychoacoustic indicators. Preliminary analyses show slightly higher levels of loudness and roughness for the new tram pass-bys while mean vibration levels stay below the typical threshold values for the average human subject.