|A study of hearing damage caused by
personal MP3 players
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) .
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
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.
||Paper, IEC test signal, Music test signal
|Realtime auralization employing a not-linear,
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
|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)
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
|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
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
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
|3dof representation of the acoustic measurements inside the Comunale-Pavarotti Theatre of Modena
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
|Acoustic parameters of the Municipal Theatre of Piacenza shown on different ways of representation
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
|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
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;
|In-Situ Measurements of Normal Impedance and Sound Absorption Coefficient of Hard Materials by using a Laser Doppler Vibrometer
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