António Oliveira de Carvalho

Since the Industrial Revolution, the intensification of rural-to-urban migration has driven the expansion of urban centers, placing increasing pressure on environmental quality and contributing to the relative loss of natural areas. In response to these challenges, various spatial arrangements aimed at public health, leisure, and sensory regeneration were developed, with urban parks assuming a strategic role. This study investigates the historical reconstruction of the soundscapes of urban parks located in São Paulo (Brazil) and Porto (Portugal), aiming to understand how the acoustic environments of these spaces have evolved over time. Adopting a historical-comparative and qualitative approach, the research is grounded in the diachronic analysis of documents that interrelate morphological, environmental, and sensory dimensions. The findings reveal that urban park soundscapes are historically embedded and territorially grounded constructs, directly influenced by design decisions, ecological dynamics, and social practices shaping everyday use. The study underscores that acoustic quality is closely linked to the ecological continuity of green systems, the protection of acoustically sensitive areas, and the design intentionality of landscape interventions. By unveiling the temporal layers that shape the sonic experience of the parks analysed, this research advances historical soundscape analysis as a critical tool in urban planning.

Tensile membrane roofs are considered to have the potential to improve the buildings’ performance due to their lightweight and flexible nature. However, their potential for improving acoustic behaviour has hardly been accurately gauged or demonstrated due to their complexity in both geometric and physical aspects. To address this issue, Carmo’s church in Lisbon—a heritage building that lost the roof during the 1755 earthquake and is nowadays a museum—was selected as case study to analyse the impact of covering high complex volumes in room acoustics by using a conventional and an alternative transparent solution: (i) a single glazing and (ii) a simple and transparent ETFE membrane tensioned in a self-supporting metal structure. This last solution is combined with a retractable cross-vaulted ceiling in a translucent and acoustic absorbent membrane supported by pneumatic ribs. The acoustic performance for music and speech emission of these two options is compared to each other and to the existing scenario—without roof—through numerical modelling and by considering a set of selected parameters: Reverberation Time, Clarity, Early Decay Time, Speech Transmission Index and Definition (D₅₀ ). These analyses allowed verifying the potential of membrane solutions to improve the acoustics of high complex volumes.

Since the Palaeolithic, Mankind has been taking advantage of the acoustical characteristics of natural caves to perform its rituals. Nowadays, many of these spaces are used as touristic attractions or even as stages for musical performances. This study characterizes three touristic caves in Portugal where in situ measurements were done, of background noise sound pressure levels, RASTI, and Reverberation Time. The average RT values were 1.3 s to 1.7 s, and the RASTI average values revealed good intelligibility (from 0.50 to 0.57). The sound absorption coefficient of the stone that constitutes the interior of those caves was also measured in a standing wave apparatus.

Since the Paleolithic, Mankind has been taking advantage of the acoustical characteristics of natural caves to perform its rituals. Nowadays many of these spaces are used as touristic attractions or even as stages for musical performances. This study characterizes three touristic caves in Portugal where in situ measurements were done, of background noise sound pressure levels, RASTI and Reverberation Time. The average RT values were 1.3 s to 1.7 s and the RASTI average values revealed good intelligibility (from 0.50 to 0.57). The sound absorption coefficient of the stone that constitutes the interior of those caves was also measured in a standing wave apparatus.

The main goal of this work is to study the soundscape of city gardens and urban parks using a sample of ten sites in Oporto, Portugal to analyze their soundscape through the acoustic characterization of the park's exterior and interior noise levels (LAeq, LA10, LA50 and LA90) and by a socio-acoustic survey to the visitors to check their perception of acoustic quality. The measurements showed gardens/parks with interior noise levels from 47 to 61 dB(A) (with exterior noise levels up to 67 dB(A)). The difference between exterior and interior LAeq was between 3 and 19 dB. The gardens with lower noise levels are the largest and out of downtown. An "acoustic" classification for gardens/urban parks is proposed regarding their noise "isolation" capacity and their acoustic ambiance. Old 1990 measurements allow for the comparison of the acoustic evolution in the last 21 years. The socio-acoustic survey concludes that Oporto's city parks are visited mostly by an elderly male population that regards these places as sites of gathering and to practice some physical activity rather than as an acoustic retreat. They seem accustomed to the dominant sound sources, classifying those spaces as pleasant and quiet, even when noise is over acceptable limits.

Rats were daily exposed (eight hours/day) for a period of four weeks to the same high-intensity wideband noise that was recorded before in a large textile plant. Histologic observation of liver sections of the rats was used to perform quantitative comparison of hepatic connective tissue (dyed by Masson trichromic staining) between the noise-exposed and control animals. For that, we have photographed at random centrolobular areas of stained rat liver sections. We found that noise exposure resulted in significant enhancement in the area of collagen-rich connective tissue present in the centrolobular domain of the rat liver. Our data strengthen previous evidence showing that fibrotic transformation is a systemic effect of chronic exposure of rodents and humans to industrial wideband noise.

I was 31 years-old when, in 1991, I left the University of Porto to study architectural acoustics at the University of Florida with Professor Gary W. Siebein. In 1994, I finished my Ph.D., I got the Robert Bradford Newman Award, and my career changed. In fact, that 1994 would be the BIG BANG of my future life. Personally, academically, and scientifically, my Universe blew up and began expanding. What I learned and what I taught in the 17 years after that (and what the architectural acoustics changed in Portugal and Southern Europe) is the subject of this paper.