Dario D'Orazio

Extraction of the envelope from impulse responses using pre-processed energy detection for early decay estimation

The Schroeders backward integration method and its applications have been widely studied in the literature; some papers analyze the performance of the method, some others suggest various enhancement techniques. In spite of these findings, there exist several cases where the energy decay curve extracted using the classical backward integration method and the parameters computed from it seem not always representative of the phenomenon under study. Among them, the cases where the early decay is dependent on strong, distinct reflections occurring just after the direct wave, as in most Italian opera houses. Other cases are measured impulse responses with a very low signal-to-noise ratio or missing the direct wave. In the literature, alternatives to the Schroeders method have been proposed, ranging from Hilbert transform to non-linear processing techniques. In this work a method for the extraction of the envelope based on pre-processed energy detection for early decay estimation is proposed. It is shown that it returns an envelope well matching the first part of the decay even in non-linear cases, returning detailed information on the first part of the decay. The performance of the proposed method is presented and discussed for some exemplary impulse responses measured in historical opera houses. A preliminary study on the perceptive relevance of the method is finally presented.

Recordings of Italian opera orchestra and soloists in a silent room

Anechoic recordings of symphony orchestras have been proposed in the literature and have been used in a multitude of studies concerning both innovative measurements and psychoacoustic experiments. Using the same approach, the present work shows the results of a recording campaign focused on the Italian Opera. Different motifs from Italian Operas have been played by professional musicians and soloists in the silent room of the Bologna University. The excerpts have been chosen because of their musical style characteristics and their acoustic properties (dynamics, timbre, vibrato). The chosen motifs come from scores of Donizetti, Verdi and Puccini, in order to consider various orchestrations and Opera styles.

Toward opera houses: Acoustic analysis of the ancient literature

From XVI Century to the present, the demand for buildings where the opera took place followed the development of the melodrama. Several authors wrote about the optimal design of an opera house. While some of them did not cross the boundaries of the theoretical research, as Milizia, others went on building theaters following their particular theories, such as Nicolini with the San Carlo theater in Naples. Early authors researched on a merely architectural systems and principles, following the classical approach—as Carini-Motta in relationship with Vitruvius. Late authors, from the XIX Century, widened the scope including social reason in the theather design. The aim of this article is to focus on the publications, regarding theatre design, of the early authors, analyzing them by highlighting the consistencies and discrepancies in respect to contemporary literature findings.

A loudspeaker orchestra for opera houses studies

A “Loudspeaker Orchestra” is an array of loudspeakers with a well-defined setup and layout. Initially proposed by contemporary composers for innovative performances (e.g., the “Acousmonium” used by the Groupe de Recherches Musicales in the 1970s), in the last years, the Loudspeaker Orchestra has been used for MIMO acoustic measurements in concert halls. In the present work, a Loudspeaker Orchestra for measurements in opera houses is proposed, taking into account the acoustic differences between a concert hall and an opera house. In fact, in a concert hall, the orchestra plays on the stage, while in an opera house, the orchestra plays in the pit, with a different layout, a smaller instrumental ensemble, etc. In a concert hall, the soloists are placed near the conductor, while in an opera house they move all over the stage, due to dramatic reasons. Basing on previous studies on room criteria and experiences with real orchestras, the authors proposed a Loudspeaker Orchestra layout for opera houses. In this w...

The role of acoustic standards in the improvement of educational spaces in Italy

A good acoustics is one of the main requirements for indoor educational spaces, where information is transmitted from a teacher to students mainly by oral communication. Often obligatory regulations do not take into account this aspect as expected, but technical standards can provide a more informed and sound reference. In Italy, a new standard is under development at UNI (the national standardization body) to provide a technical framework for the design and use of teaching rooms in schools and a guideline has been released by AIA (Italian Acoustical Association) to provide a comprehensive, easy-to-read guide to authorities and stakeholders on the acoustical design of schools. The underlying principles and methods will be presented and discussed, as well as the way they are taught in University courses in order to raise awareness on these topics in future engineers and architects.