Bullervågor

Bullervågor is a Swedish term commonly used in acoustics and environmental noise literature to describe noise waves—random or irregular sound-pressure fluctuations in air. The word buller means noise, vågor means waves. Unlike pure tonal waves, bullervågor typically have broad frequency content and variable amplitude, resulting from complex source motion or multiple sources acting together, such as traffic, industrial equipment, or crowd noise. They can be continuous, intermittent, or impulsive.

Physical properties involve pressure variations that propagate as sound waves through air at the speed of sound (about 343 m/s in air at 20°C). Bullervågor are characterized by their level (sound pressure level, SPL), spectrum, temporal pattern, and duration. Measurement often uses A-weighted decibels (dBA) to reflect human hearing sensitivity. Key metrics include L_Aeq (equivalent continuous level) and L_Amax (maximum level).

Propagation and attenuation describe how bullervågor spread from the source, typically diminishing with distance and interacting with terrain, buildings, and atmospheric conditions. They can be reflected, refracted, or diffracted by obstacles, and ground effects and humidity influence their propagation. Interference between sources can cause spatial variations in loudness.

Health and mitigation address the impacts and management of bullervågor. Prolonged exposure to elevated bullervågor can cause hearing risk and sleep disturbance. Mitigation strategies include source control, increasing distance, installing sound barriers, improving vibration isolation, and employing quieter technologies or effective urban planning.

Note: The term is largely descriptive in Swedish and not a formal physics category; in English, such signals would be discussed under general environmental or acoustic noise.