Ruoran Yan

Three principal interior spaces of the Royal Palace of Caserta: a court theatre (Teatro di Corte), a royal chapel (Cappella Palatina), and a grand staircase (Scalone Reale), represent acoustically distinct architectural typologies within a single architectural complex, enabling direct acoustic comparison using a common measurement protocol. This study combines independently processed room acoustic parameters with spatial energy analysis to compare reverberation and receiver-dependent acoustic patterns across the three spaces. Measurements were conducted under unoccupied conditions following ISO 3382-1, using an omnidirectional source, an omnidirectional reference microphone and a 32-channel Eigenmike EM32 spherical microphone array. Mid-frequency mean reverberation time T ₃₀ , averaged over the 500 Hz and 1 kHz octave bands, was 2.4 s in the Teatro di Corte, 5.4 s in the Cappella Palatina and 8.2 s in the Scalone Reale, a more than threefold range within a single building reflecting the contrasting acoustic typologies of the three spaces. The Scalone Reale exhibits prolonged reverberation across all six measured positions, together with positional variation in early energy; its connected geometry provides a basis for discussing energy exchange as a possible influence on the observed decay. Relative sound energy maps derived from the spherical array show spatial patterns within selected early and later time windows at representative receiver positions, supporting interpretation of the acoustic response in relation to the surrounding architectural surfaces. The results bring the three interiors into a joint comparison of reverberation and spatial energy patterns and provide a quantitative reference for assessing the acoustic effects of future physical changes to the building fabric and use conditions of each space.

Historical theatres encompass diverse architectural typologies whose influence on spatial acoustic parameters has not been systematically quantified across building types. This study presents binaural and lateral energy measurements at 52 receiver positions in five European theatres spanning three architectural subtypes: traditional horseshoe with enclosed boxes, modified horseshoe with open continuous galleries, and a modern rectangular proscenium auditorium. Linear mixed-effects models were used to separate the fixed effects of seating zone from random variability among venues. Seating zone had a highly significant effect on IACC and LF (p < 0.0001). IACC exhibited a binary spatial distribution, with Stalls Front positions approximately 0.17–0.20 higher than all other zones, which were mutually indistinguishable. LF followed a gradient across four seating levels, increasing from Stalls Front through Stalls Rear and Lower Boxes to Upper Boxes. Architectural typology, rather than room volume, appeared to explain inter-venue IACC differences most clearly. The single modern rectangular theatre exhibited IACC values approximately 2.5 times higher than all other venues, a difference attributable to its flat specular surfaces and rectangular plan rather than to room volume (Spearman rank correlation: ρ = 0.10, p = 0.87). The theoretically expected negative correlation between IACC and LF was confirmed within the horseshoe theatres (r = -0.38, p = 0.009) but was suppressed when the rectangular theatre was included. These results show that specular lateral reflections can decouple IACC and LF, with implications for acoustic assessment in typologically diverse performance spaces.

Theaters in ancient Pompeii played a vital role in Roman entertainment, shaping the auditory experiences of spectators. This study examines the acoustic properties of the Amphitheater, the Grand Theater, and the Odeon using impulse response (IR) analysis to reconstruct their soundscapes. Next, the study considers the impact of typical musical instruments, vocal performances, and ambient sounds—such as gladiatorial combat—on these spaces’ acoustics. Findings reveal significant differences in reverberation times, sound clarity, and spatial characteristics, shaped by each theater’s design. These sites, preserved after the eruption of Mount Vesuvius, provide a unique opportunity to analyze how architecture influenced sound propagation. The Amphitheater, with its vast open structure, enhanced large-scale events, while the Grand Theater’s semi-enclosed design balanced musical and theatrical performances. The Odeon, the most intimate of the three, prioritized speech clarity. These insights highlight how Roman architects engineered performance spaces to accommodate diverse entertainment forms. By combining acoustic measurements with historical context, this research offers a deeper understanding of ancient Pompeii’s soundscapes and the auditory experiences of its inhabitants and offers insights for composition and soundscape creations that take inspiration from these prominent historical architectural and cultural icons whilst exploring its potential within contemporary immersive listening practices.

The Ponchielli theater of Cremona was built in 1808 after a fire destroyed the old wooden structure. The interior, the architecture and the shape of the plan layout are reminiscent of the Teatro alla Scala, Milan, a masterpiece by the architect Piermarini, albeit on a smaller scale. The four orders of balconies crowned by the top gallery are typical features of a 19th Century Italian Opera theater. Acoustic measurements have been undertaken across the stalls and in some selected boxes according to ISO 3382. The main acoustic parameters resulting from the measurements have been used for the acoustic calibration of a 3D model representing the Ponchielli theater. The calibration has been used to compare different scenarios involving the acoustic response of the main hall at 50% and 100% occupancy. The outcomes indicate that no significant change can be detected when the seats are provided with robust upholstery, which can be considered a positive result, especially for the actors who are not forced to change their effort between rehearsal and live performance. In order to contextualize the measured values in relation to the optimal ones, a comparison with other Italian Opera theaters provided with similar architectural characteristics has been carried out. Overall, the findings indicate that the acoustics of the Ponchielli theater are suitable for both music and speech in line with the other selected theaters, as these places were mainly created for multifunctional purposes in the 19th Century.

Equipment, sound sources, operators, microphone placement, calculation techniques, and thermal–humidity measurement conditions all have an impact on the measurement of impulse responses when several channels are present. However, the thermal–humidity variable, which is a significant component of these factors impacting the assessment of acoustic characteristics, is commonly overlooked in research. The effects of altering temperature, relative humidity, and air velocity on acoustic parameters are investigated in this paper through experimental activities carried out in an experimental room. The patterns of fluctuation of a range of room acoustic characteristics are examined, data are acquired, and statistical analyses based on R (language and environment for statistical computing and graphics) are generated in order to ascertain the relationship between the variation of acoustic parameters and the variation of thermo-hygrometric parameters. Finally, a statistical analysis reveals relationships between thermal and hygrometric variables and interior acoustic characteristics.

The acoustic characteristics and spatial features of the world’s only surviving Italianate Gordonia-style miniature theatre, one of the smallest theatres in the world, have inspired the author to analyse the acoustic behaviour of the Monte Castello di Vibio theatre, also called “Teatro della Concordia”. In this paper, the geometric and architectural features of this historical and unique performing art space were first reproduced, considering that these features are essential factors affecting acoustic characteristics. Subsequently, the acoustic measurements were taken throughout the stall and inside some selected boxes, and their main parameters were acoustically characterised according to ISO 3382-1. Lastly, the main acoustic parameters of the Monte Castello di Vibio theatre were compared to those of the 1763 theatre in Bologna, which is also a miniature theatre of similar size. The aim is to explore the main influences on the acoustic parameters of miniature theatres, and the results show that the plan layout of the theatre and interior decoration are the main factors influencing the acoustic characteristics rather than volume. Preserving the acoustic features of this unique heritage building is also seen as one of the goals of this paper.

Indoor environment is closely related to people’s life, its quality directly affects the quality of people’s life, the indoor environment is a comprehensive environment, however, the current research on indoor environmental comfort are mostly just in view of indoor thermal, optical, acoustic environmental comfort or some aspect of the air quality, and not to combine it. The fusion evaluation algorithm of indoor thermal environment comfort based on neural network is adopted, which can realize the comprehensive design of indoor environment better.