3D Impulse Response Analysis and Acoustic Signature for the Sound Heritage of the Campo Pequeno Bullring in Lisbon, Portugal

Bullfighting in the bullrings of the Iberian Peninsula, with its most direct antecedent in the Roman amphitheatre, represents an established tradition that has been exported to the Americas. Bullfighting in Portugal shares general aspects with the bullfighting culture in neighbouring Spain. However, in Portugal, particular aspects are present: there is a preference for horseback bullfighting (cavaleiros) and forcados (a special type of bullfighting), and the bull is not killed in the ring. In this work, the authors aim to contribute to the acoustic narrative of bullfighting by linking architecture with the sounds of voice, environment, music, and silence that manifest in the emblematic Campo Pequeno bullring in Lisbon, thereby providing valuable information regarding its unknown intangible acoustic heritage. The presence of a mobile roof increases the number of reflections in the bullring, leads to a more linear energy decay, and prevents the acoustic inconveniences of roofless performance venues. The 3D impulse response measurements enable an overall monaural parametric analysis, together with the analysis of the distribution of sound energy in the time–frequency domain of early reflections, to determine the acoustic signature of the venue complemented with the direction of arrival of these early reflections.