Title Authors Year Link
A study of hearing damage caused by personal MP3 players
Abstract This paper aims to assess the actual in-hear sound pressure level during use of mp3 players. The method is based on standard EN 50332 (100dB as maximum SPL), IEC 60959 (HATS) and IEC 60711 (ear simulators), as explained in the January 2007 issue of the Bruel and Kjaer Magazine (page 13) [1]. In this study a number of MP3 players were tested, employing a dummy head and a software for spectrum analysis. The measurements were aimed to assess the hearing damage risk for youngsters who employ an MP3 player for several hours/day. The students of an Italian high school (15-18 years old) were asked to supply their personal devices for testing, leaving untouched the gain from the last usage. The results show that the risk of hearing damage is real for many of the devices tested, which revealed to be capable of reproducing average sound pressure levels well above the risk threshold.
Adriano Farina 2007 Paper, IEC test signal, Music test signal
Realtime auralization employing a not-linear, not-time-invariant convolver
Abstract The paper reports the first results of listening tests performed with a new software tool, capable of not-linear convolution (employing the Diagonal Volterra Kernel approach) and of time-variation (employing efficient morphing among a number of kernels). The listening tests were done in a special listening room, employing a menu-driven playback system, capable of presenting blindly sound samples recorded from real-world devices and samples simulated employing the new software tool, and, for comparison, samples obtained by traditional linear, time-invariant convolution. The listener fills up a questionnaire for each sound sample, being able to switch them back and forth for better comparing. The results show that this new device-emulation tool provides much better results than already-existing convolution plugins (which only emulate the linear, time-invariant behavior), requiring little computational load and causing short latency and prompt reaction to user???s action.
Angelo Farina, Adriano Farina 2007 Paper, Presentation
First description of the sound pressure and particle velocity components of the ambient noise and boat noise recorded at the WWF- Miramare Natural Marine Reserve (Trieste, Italy)
Abstract Boat noise represents a chronic source of harassment for fish species, whose communication for inter- and intra-sexual selection is mainly based on low frequency sound signals (Amorim 2006). Investigating the impact of boat noise on target fish species is particularly relevant for coastal MPAs, which are biologically rich locations deserving protection from anthropogenic pollutants. Although many fish species are primarily sensitive to the kinematic components of the sound field (Popper and Fay 1999), namely to particle acceleration, boat noises have been characterized so far mostly by means of sound pressure measurement. In this work, the underwater acoustic background noise, and the noise produced by a small outboard-engine boat moving at 6 knots, were recorded inside the WWF-Natural Marine Reserve of Miramare (Trieste, Italy) by using a novel hydrophonic probe (???Soundfish???) placed on the sea bottom (8 meters depth). This allowed for characterization of the sound field not just in terms of sound pressure, but also of the three Cartesian components of the particle velocity.
Angelo Farina, Adriano Farina, Enrico Armelloni, Linda Sebastianutto, Carlo Franzosini, Marta Picciulin 2010 Paper
A comparison of different surround sound recording and reproduction techniques based on the use of a 32 capsules microphone array, including the influence of panoramic video
Abstract This paper provides a comparison between the operational results obtained reproducing a three-dimensional sound field by means of traditional 1st order Ambisonics, and employing for the first time the virtual microphone technique 3DVMS. Audio and video were recorded at the same time, employing 32-capsules spherical microphone arrays and a panoramic video capture system of our design. In both cases, a matrix of FIR filters was employed, for deriving the standard 4 B-format components (Ambisonics), or 32 highly- directive virtual microphones pointing at the same directions of the 32 loudspeakers (3DVMS). A pool of test subjects was employed for comparative listening tests, evaluating some standard psycho- acoustical parameters. Furthermore, the same tests were repeated with and without the accompanying panoramic video. The tests were performed inside the 3Sixty room in the University of York, an immersive space with all- around video projection and a 32 speakers array. A complete set of IRs has been measured placing a microphone in the center of the room and sending a sine sweep test signal to each of the 32 loudspeakers. These IRs have been employed for equalizing individually each loudspeaker for Ambisonics and 3DVMS playback. In addition to this, we experimented with the capture of a live performance inside the room and with the virtual reconstruction of the complete audio-visual experience.
Fabio Manola, Andrea Genovese, Adriano Farina 2012 Paper
3dof representation of the acoustic measurements inside the Comunale-Pavarotti Theatre of Modena
Abstract The investigation of the acoustics inside the Italian Opera theatres has been undertaken by scholars in order to deepening their scientific studies on the architectural and cultural heritage. This paper deals with alternative ways of how to represent acoustic data, in particular by adding a 3dof representation of the impulse response (IR) besides the graphs related to the main acoustic parameters in line with the standard requirements. The 3dof screen shots have been undertaken by an overlay elaboration, showing the particular architectural components of the theatre that contribute to the early and late sound reflections. A brief introduction of the historical background related to the Comunale-Pavarotti theatre of Modena has been given to understand the architectural characteristics of the entire structure.
Antonella Bevilacqua; Francesca Merli; Angelo Farina; Enrico Armelloni; Adriano Farina; Lamberto Tronchin 2021 Paper
Acoustic parameters of the Municipal Theatre of Piacenza shown on different ways of representation
Abstract The Italian Opera theatres are always subject to scientific studies that try to investigate as deeply as possible this historical heritage to preserve the architectural and acoustical information for future generations. This paper deals with two ways of data representations based on the outcomes derived from the variety of equipment used during the measurements. In particular, a methodology in line with standards and regulations has been introduced to representing the graphs of the main acoustical parameters; besides, a video of the real-time room impulse response (RIR) has been snapped with a few shots in place of visualizing the sound reflections that occurred inside the entire volume. After a brief description of the historical background of the Municipal theatre of Piacenza, the authors introduce the two methods just discussed to highlight the completeness of data representation regarding any type of room that is intended to be analyzed acoustically.
Antonella Bevilacqua; Francesca Merli; Enrico Armelloni; Angelo Farina; Adriano Farina; Lamberto Tronchin 2021 Paper
Acoustic Design Review for the Historical Aula Magna at the University of Parma. Measurement and Simulation Tools to Predict the Amount of Absorption to be put in Place
Abstract The Aula Magna (great hall) of the University of Parma, historically known as the Hall of the Philosophers, is part of a 16th-century palace located in the core of the city. The Aula Magna hosts official ceremonies and graduations. The geometrical composition of the room, provided with a wagon vault, and the high level of reflections due to the hard finish materials lead to a poor quality of speech intelligibility. This paper deals with an acoustic design review of the current furniture inside the auditorium, with the purpose of adjusting the acoustic parameters to be suitable for the current uses of the room. Acoustic measurements have been undertaken in accordance with the standard requirements outlined by ISO 3382-1, capturing the existing conditions of the hall. A highly accurate digital model of the room was obtained with photogrammetry and modelling, in order to carry out numerical simulations regarding the implementation of the acoustic treatments. The quantity and quality of the proposed absorbing panels improve the listening conditions to a degree of comfort assessed against the criteria set by UNI 11532-2:2020.
Angelo Farina; Antonella Bevilacqua; Adriano Farina; 2022 Poster
In-Situ Measurements of Normal Impedance and Sound Absorption Coefficient of Hard Materials by using a Laser Doppler Vibrometer
Abstract Standard techniques to measure the sound absorption coefficient or the acoustic impedance of materials are the Kundt???s tube and the reverberant room, albeit they are not practicable in-situ. In addition, these measurement methodologies involve extracting small or large samples of the material under test, which is not permitted for materials of historical importance. In this paper, the possibility of determining the normal acoustic impedance and the normal sound absorption coefficient based on direct in-situ measurements using a Laser Doppler Vibrometer (LDV) has been analyzed. Specifically, measurements have been conducted avoiding any contact on historical sandstones, bricks, and wood planks of the Greek-Roman Theater of Tyndaris located in Sicily (Italy).
Saccenti, Leonardo; Armelloni, Enrico; Farina, Adriano; Bevilacqua, Antonella; Lavagna, Lorenzo 2022 AES E-Library
New method for the computation of acoustical parameters according to the updated Italian Legislation
Abstract Standard acoustic parameters such as reverberation time T20 and clarity C50 are measured or calculated according to ISO 3382-1. The additional parameter STI (Speech Transmission Index) is measured or calculated according to the IEC 601268-16 standard, recently upgraded in 2020. In Italy, it is a legal requirement to verify the values of these acoustic parameters for new public buildings, both in the design phase (calculated values) and in the official assessment of the building performance (measured values). The relevant legislation was drafted in 1997, updated in 2017 with the introduction of the minimum environmental criteria (Decree of the Ministry of the Environment of 11/10/2017), and recently further updated with the Decree by Ministry of Ecological Transition No. 256 of 23/06/2022. This decree became legally effective in December 2022 and is still very innovative at the time of writing. It requires that the values of three ???advanced??? acoustic parameters (T20, C50 and STI) be evaluated in all new public buildings, with particularly severe prescriptions in the values to be achieved in special categories of buildings, such as schools. These advanced acoustic parameters are additional to the standard ones, such as the sound reduction index of partitions and facades, the impact sound level and the noise level generated by HVAC systems, which are mandatory in Italy for all types of buildings since the introduction of DPCM 5/12/1997. This paper deals with these three advanced acoustic parameters, which have only recently become mandatory, and describes the update of the Ramsete and Aurora software packages, widely used in Italy to perform predictive calculations and experimental verification of these ???room acoustic??? parameters. Recent updates to these software tools make them compatible with the newer version of the standards, and hence with the new legislation. In particular, these developments now include a new method for calculating the room impulse response, and hence the STI value, taking into account the different orientations of the speaker, synthesizing the corresponding voice directivity balloon. This new STI(?) measurement allows the evaluation of the speech intelligibility index for the case when the speaker is not facing the listener. This result can be obtained both experimentally and in computer simulations by evaluating the MIMO Room Impulse Response, and then synthesizing a virtual source with the standardized human voice directivity and proper aiming.
Bevilacqua, Antonella; Farina, Adriano; Saccenti, Leonardo; Farina, Angelo 2023 AES E-Library
MIMO Technique applied to the Greek Theatre of Tyndaris
Abstract Spatial Multiple Input Multiple Output (MIMO) is an innovative technique developed to provide an appropriate filter array required to virtually reconstruct the perceived sound field at the listener's position, generated by a sound source with arbitrary and time-varying directivity. This is particularly useful when the sound source has a complex directivity pattern (e.g. the human voice or specific musical instruments). To mimic the directivity of a real sound source, a “DodecMIMO” was developed. This prototype loudspeaker is capable of simulating the directivity of any dynamic sound source as well as a standard omnidirectional sound source. Prior to field applications, the sound source was measured in an anechoic chamber to obtain its acoustic characterization. The first on-site application took place in the Greek-Roman theatre of Tyndaris (Sicily, Italy). The measured impulse responses (IRs) were analyzed and compared with previous acoustic studies performed with omnidirectional sound sources. The outcomes were used to compute the acoustic maps for each measuring point by overlapping the panoramic image acquired at each position with the acoustic response recorded by the microphone. This innovative technique is very well suited to create a virtual 3D audio reproduction, technically called auralization, which can faithfully reproduce a complex real sound source.
Armelloni, Enrico; Saccenti, Leonardo; Bevilacqua, Antonella; Lavagna, Lorenzo; Shtrepi, Louena; Astolfi, Arianna; Farina, Adriano; Farina, Angelo; 2023 Paper