Search Results (11)

In this paper, the acoustic characteristics of the most important rooms of the Royal Palace of Caserta are presented. The palace, built in the XVIII century as a residence for the King of Naples, consists of numerous rooms dedicated to court life. The acoustic properties of the rooms have been studied according to ISO 3382. For each room, the average values of reverberation time (T30), clarity (C80), definition (D50), and Speech Transmission Index (STI) are reported. The acoustic issues of the rooms are highlighted as the understanding of acoustics during the period in which the palace was constructed was limited. While the rudiments of Vitruvius’ theories were known, the good acoustics of the rooms resulted primarily from the intuition and experience of the architects who designed them. The building materials—marble and plaster—contribute to the long reverberation times in the rooms. Special attention was given to the elliptical vault where musicians were positioned, the Palatine Chapel, the theatre used for court entertainment, and the Royal Throne Room. The study applies methods and techniques already seen in the literature and already reported in other published papers. Full article

Thousands of theatres were built during the Hellenistic period in Greece and overseas colonies. The main elements of the Hellenistic theatre are the following: the orchestra, where music and songs were performed to accompany the acting performance, and the koilon, where the audience sat. Hellenistic theatres were built without any ceiling, with an open-air configuration. This paper reports the acoustic characteristics of the Greek (Hellenistic) theatre located in Morgantina (Sicily, Italy) based on the technical data gathered in different listening positions selected across the sitting area (koilon). The theatre of Morgantina was built in the third century BC and renovated a few decades ago. Nowadays, it is the center of important social and cultural activities. The outcomes of the beamforming technique employed for the survey have been discussed in comparison with traditional acoustic parameters, such as ISO 3382. The scope of this article is to assess the usability of this theatre intended to be used for different types of artistic performances. Full article

The discovery of Roman amphitheaters continues to excite the minds of archaeologists. Within the framework of various excavation campaigns, the architectural requalification of the amphitheater of Durres has been investigated, but no acoustic analyses have yet been carried out. This paper deals with the acoustic reconstruction of the Roman amphitheater of Durres in its original form. A campaign of acoustic measurements was carried out in accordance with ISO 3382 in order to understand the existing conditions, which are very detrimental to any type of live performance. After an accurate analysis of the geometric composition of the building, acoustic simulations were performed to determine the original acoustic response of the building. A comparison of the measured and simulated results, with and without an audience, was made in terms of the main acoustic parameters, while the acoustic map showing the spatial distribution of speech clarity at 1 kHz was added as an alternative way of representing the data. The outcomes show that the results related to the original shape are closer to the optimal values than the existing conditions. Full article

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. Full article

The Byzantine churches built between the 7th and the 15th centuries represent an architectural typology that has been developed along with other architectural styles. The evolution of the interior organization, to be composed of only a single nave for the oldest architecture and then developed with additional lateral naves, is one of the multiple aspects that characterizes this building type, studied mainly from an architectural perspective. The variety of roof morphology, being flat, double slope, vaulted or domed, contributes to determining the overall acoustics. This paper deals with the analysis of the acoustic characteristics related to five Byzantine churches located in Albania, specifically in Berat and Cete. A comparison of the impulse response (IR) measured inside each church was given by analyzing the most appropriate acoustic parameters and in line with ISO 3382. The acoustic surveys were undertaken with a minimal furniture and without any audience. The results highlight small difficulties in terms of speech understanding, especially under a speech clarity index found to be below the optimal range limit. This shortfall is attributed to the geometry of the volumes and to the reflecting materials applied to the surfaces that facilitate the build-up of sound energy. Full article

During the Imperial Roman period, thousands of theatres were built. The theatres have three principal elements: the scene building (actor position), the orchestra and the cavea (spectator seating). The theatres were built without a roof, so they were open-air spaces. The theatres were abandoned afterward the barbarian invasions, and during the Middle Ages, homes were built inside the cavea. The theatres were rediscovered during the Renaissance period. Today, ancient theatres are the center of cultural events and are used for various kinds of shows. This work discussed the acoustics of the Roman theatre of Benevento, which was built during the Imperial Age. The theatre was destroyed after the barbaric invasion and it was rebuilt in the first half of the 1900s. The theatre was opened in 1957, and today it is the center of social and cultural activities. Acoustic measurements were carried out according to ISO 3382 standard, placing an omnidirectional sound source on the scene building and in the orchestra, with the measurement microphones along three directions in the cavea. The acoustic characteristics in various seating areas of the cavea were evaluated. Therefore, it possible to understand in which sectors of the theatre the acoustic characteristics are optimal for different types of theatrical performances. Full article

A handclap is a convenient and easily available source for room acoustic measurements. If used correctly (e.g., application of optimal hand configuration) it can provide usable results for the measurement of acoustic parameters, within an expected deviation. Its biggest drawbacks are the low sound pressure level (especially in the low frequency range) as well as its low repeatability. With this in mind, this paper explores the idea of testing a handclap with a glove in order to assess the effect on its source characteristics. For this purpose, measurements were performed with 12 participants wearing leather gloves. Sound levels were compared with simple handclaps without gloves, and between grouped results (overall A-weighted SPL, octave bands, 1/3 octave bands). Measurements were also performed several times to evaluate the effect on repeatability. Results indicate that the use of leather gloves can increase the sound levels of a handclap by 10 dB and 15 dB in the low frequency ranges (63 Hz and 125 Hz octave bands, respectively). Handclaps with leather gloves also point toward improved repeatability, particularly in the low-frequency part of the frequency spectrum. In conclusion, compared to simple handclaps without gloves, evidence from this study supports the concept that handclaps with leather gloves can be used in engineering practices for improved room acoustic measurements of room impulse response. Full article

Diffusive surfaces are considered as one of the most challenging aspects to deal with in the acoustic design of concert halls. However, the acoustic effects that these surface locations have on the objective acoustic parameters and on sound perception have not yet been fully understood. Therefore, the effects of these surfaces on the acoustic design parameters have been investigated in a real shoebox concert hall with variable acoustics (Espace de Projection, IRCAM, Paris, France). Acoustic measurements have been carried out in six hall configurations by varying the location of the diffusive surfaces over the front, mid, and rear part of the lateral walls, while the other surfaces have been maintained absorptive or reflective. Moreover, two reference conditions, that is, fully absorptive and reflective boundaries of the hall have been tested. Measurements have been carried out at different positions in the hall, using an artificial head and an array of omnidirectional microphones. Conventional ISO 3382 objective acoustic parameters have been evaluated in all conditions. The results showed that the values of these parameters do not vary significantly with the diffusive surface location. Moreover, a subjective investigation performed by using the ABX method with auralizations at two listening positions revealed that listeners are not sensitive to the diffusive surface location variations even when front-rear asymmetric conditions are compared. However, some of them reported perceived differences relying on reverberance, coloration, and spaciousness. Full article

Handclap is a convenient and useful acoustic source. This study aimed to explore its optimal application and limitations for acoustic measurements as well for other possible utilizations. For this purpose, the following steps were performed: investigation of the optimal hand configuration for acoustic measurements and measurements at different microphone source distances and at different spaces and positions. All measurements were performed with a handclap and a dodecahedron speaker for comparison. The results indicate that the optimal hand configuration (among 11) is with the hands cupped and held at an angle due to the superior low frequency spectrum. This configuration produced usable acoustic parameter measurements in the low frequency range in common room background levels unlike other configurations. The reverberation time was measured across different spaces and positions with a deviation less than three and just a noticeable difference of the signal-to-noise ratio within or near the ISO 3382-1 limits for each corresponding octave band. Other acoustic parameters (i.e., early decay time, clarity) were measured with greater deviations for reasons discussed in the text. Finally, practical steps for measurements with a handclap as an acoustic source are suggested. Full article

An omnidirectional source is required in many acoustic measurements. Commonly a dodecahedron speaker is used but due to various factors (e.g., high cost, transportation difficulties) other acoustic sources are sometimes preferred. In this review, fifteen acoustic source alternatives to a dodecahedron speaker are presented while emphasis is placed on features such as omnidirectionality, repeatability, adequate sound pressure levels, even frequency response, accuracy in measurement of acoustic parameters and fulfillment of ISO 3382-1 source requirements. Some of the alternative acoustic sources have the appropriate features to provide usable results for acoustic measurements, some have acoustic characteristics better than a dodecahedron speaker (e.g., omnidirectionality in the high-frequency range), while some can potentially fulfill the ISO 3382-1 source requirements. Collected data from this review can be used in many areas (e.g., ISO measurements, head-related transfer functions measurements) for the appropriate selection of an acoustic source according to the expected use. Finally, suggestions for uses and future work are given aimed at achieving further advances in this field. Full article

In a Historical Opera House (HOH), the proscenium is the foreground part of the stage. Until the end of the 19th Century, it was extended through the cavea, being the orchestra placed at the same level of the stalls, without an orchestra pit. Soloists often moved in the proscenium when they sung, in order to increase the strength of the voice and the intelligibility of the text. The Alighieri theatre in Ravenna, designed by the Meduna brothers, the former designers of Venice’s “La Fenice” theater, is chosen as a case study. During a refurbishment in 1928, the proscenium of the stage was removed in order to open the orchestra pit, which was not considered in the original design. The original design and the present one are compared by using numerical simulations. Acoustic measurements of the opera house and vibro-acoustic measurements on a wooden stage help to reach a proper calibration of both models. Results are discussed by means of ISO 3382 criteria: the proscenium increases the sound strength of the soloists but reduces the intelligibility of the text. Full article