Journal articles: JMUI and JASA 2016

Double win for PADVA project!!!









Two fresh new journal papers are going to be published.



This paper is an invited publication and extended version of Michele and Federico ‘s ICAD 2015 publication.

M. Geronazzo, F. Avanzini, and F. Fontana.
Auditory navigation with a tubular acoustic model for interactive distance cues and personalized head-related transfer functions.
Journal on Multimodal User Interfaces, May 2016. (link to JMUI page)


This paper presents a novel spatial auditory display that combines a virtual environment based on a Digital Waveguide Mesh (DWM) model of a small tubular shape with a binaural rendering system with personalized head-related transfer functions (HRTFs) allowing interactive selection of absolute 3D spatial cues of direction as well as egocentric distance. The tube metaphor in particular minimizes loudness changes with distance, providing mainly direct-to-reverberant and spectral cues. The proposed display was assessed through a target-reaching task where participants explore a 2D virtual map with a pen tablet and hit a sound source (the target) using auditory information only; subjective time to hit and traveled distance were analyzed for three experiments. The first one aimed at assessing the proposed HRTF selection method for personalization and dimensionality of the reaching task, with particular attention to elevation perception; we showed that most subjects performed better when they had to reach a vertically unbounded (2D) rather then an elevated (3D) target. The second experiment analyzed interaction between the tube metaphor and HRTF showing a dominant effect of DWM model over binaural rendering. In the last experiment, participants using absolute distance cues from the tube model performed comparably well to when they could rely on more robust, although relative, intensity cues. These results suggest that participants made proficient use of both binaural and reverberation cues during the task, displayed as part of a coherent 3D sound model, in spite of the known complexity of use of both such cues. HRTF personalization was beneficial for participants who were able to perceive vertical dimension of a virtual sound. Further work is needed to add full physical consistency to the proposed auditory display.


We are so proud of this JASA paper resulting from a joint collaboration with the Dept. of Computer Science at Aalto University School of Science (Finland).

S. Prepelita, M. Geronazzo, F. Avanzini, and L. Savioja.
Influence of voxelization on finite difference time domain simulations of head-related transfer functions.
Journal of the Acoustical Society of America, April 2016. (link to JASA page)


The scattering around the human pinna that is captured by the Head-Related Transfer Functions (HRTFs) is a complex problem that creates uncertainties in both acoustical measurements and simulations. Within the simulation framework of Finite Difference Time Domain (FDTD) with axis-aligned staircase boundaries resulting from a voxelization process, the voxelization-based uncertainty propagating in the HRTF-captured sound field is quantified for one solid and two surface voxelization algorithms. Simulated results utilizing a laser-scanned KEMAR mesh show that in the context of complex geometries with local topology comparable to grid spacing such as the human pinna, the voxelization-related uncertainties in simulations emerge at lower frequencies than the generally used accuracy bandwidths. Numerical simulations show that the voxelization process induces both random error and algorithm-dependent bias in the simulated HRTF spectral features. Frequencies fr below which the random error is bounded by various dB thresholds are estimated and predicted. Particular shortcomings of the used voxelization algorithms are identified and the influence of the surface impedance on the induced errors is studied. Simulations are also validated against measurements.

IJHS paper: got the star!

We are honored that our publication

Geronazzo, M., Bedin, A., Brayda, L., Campus, C., Avanzini, F., 2016. Interactive spatial sonification for non-visual exploration of virtual maps. International Journal of Human-Computer Studies, Data Sonification and Sound Design in Interactive Systems 85, 4–15. doi:10.1016/j.ijhcs.2015.08.004

received such an important endorsement from the Editors-in-Chief, Professor Enrico Motta. Check this out in the star after the paper title!

IJHS paper got a star!

Elsevier is providing the following personal article link, which will provide free access to our article, and is valid for 50 days, until December 25, 2015

Anyone who clicks on the link until December 25, 2015, will be taken to the final version of your article on ScienceDirect for free. No sign up or registration is needed – just click and read!

The PADVA team

PADVA was @ ICSV22 and 42nd AIA meeting

AIA_EricaLast week we were in Florence for two scientific events:

  • the 22nd edition of the International Congress on Sound and Vibration (ICSV22), where Simone presented the invited paper Subjective evaluation of a low-order parametric filter model of the pinna for binaural sound rendering (S. Spagnol, S. Scaiella, M.Geronazzo, F. Avanzini) within the Special Session on Analysis, Perception and Render of 3D Spatial Sound;
  • the 42nd Italian Acoustic Association (AIA) meeting in Pisa where our student Erica Tavazzi presented the paper Discriminazione della distanza relativa tra sorgenti sonore virtuali [Relative distance discrimination of virtual sound sources] (E. Tavazzi, S. Spagnol, F. Avanzini), based on a follow-up of her Bachelor’s work.

Both works were quite well-received by the audience!


ICAD in Space

ICAD 2015 @ Graz was a great event!

PADVA contributed successfully to the special topic “ICAD in space” with three scientific contributions:

  • S. Spagnol, and F. Avanzini “Anthropometric Tuning of a Spherical Head Model for Binaural Virtual Acoustics Based on Interaural Level Differences” in Proc. of the 21st  Int. Conf. on Auditory Display (ICAD 2015), Graz, Austria, 2015, pp. 204–209.
  • M. Geronazzo, F. Avanzini, and F. Fontana, “Use of Personalized Binaural Audio and Interactive Distance Cues in an Auditory Goal-Reaching Task” in Proc. of the 21st  Int. Conf. on Auditory Display (ICAD 2015), Graz, Austria, 2015, pp. 73–80.
  • B. Boren, M. Geronazzo, F. Brinkmann, and E. Choueiri, “Coloration Metrics for Headphone Equalization” in Proc. of the 21st  Int. Conf. on Auditory Display (ICAD 2015), Graz, Austria, 2015, pp. 29–34.

Have a look at this link for a complete list of PADVA scientific publications.

Check them out in the ICAD proceedings.


IEEE 2nd VR Workshop on Sonic Interactions for Virtual Environments


We are glad to announce the first official event organized by PADVA: the second IEEE workshop on Sonic Interactions in Virtual Environments (SIVE), satellite event of the IEEE Virtual Reality Conference.

SIVE will take place in Arles, on March 24. The main goal is to increase among the virtual reality community the awareness of the importance of sonic elements when designing virtual environments. SIVE will also discuss how research in other related fields such as film sound theory, product sound design, sound and music computing, game sound design and computer music can inform designers of virtual reality environments. Moreover, SIVE will feature state of the art research on the field of sound for virtual environments.
More information available at the official webpage.

PADVA’s research will also be presented by Federico with the paper

“Evaluating Vertical Localization Performance of 3D Sound Rendering Models with a Perceptual Metric”
by Michele Geronazzo, Andrea Carraro, and Federico Avanzini.

Conference article: Personalization Support for Binaural Headphone Reproduction in Web Browsers

Tomorrow the 1st Web Audio Conference (WAC) will start. The closing talk of the first day will be “Personalization Support for Binaural Headphone Reproduction in Web Browsers” (full text) by Michele Geronazzo, Jari Kleimola, and Piotr Majdak. The mission of PADVA in promoting individualization support for spatial audio rendering will be brought to the attention of the international web audio community.

The future of 3D-media environments and broadcasting is constantly moving towards high spatial fidelity in sound field reproduction systems that are able to allow personal fruition of spatialized audio contents, leading to the next generation of portable audio devices. Audio technologies should be fully integrated with mobile devices and browsers, being able to provide an authentic individual listening experience.
This study propose a web framework with Web Audio API, giving support to the download of head-related transfer functions (HRTFs) associated with listener’s personal profile from a server and the synchronization between the listener’s devices. With each playback device and listener, the individual headphone equalization filters will be computed from headphone transfer functions (HpTFs) stored on the server. At server side, we propose to store the HRTFs and HpTFs in spatially oriented format for acoustics (SOFA). At client-side, we propose to convert the data to a new structure (WAV) ensuring a compatible solution with existing Web Audio API implementations. A binaural rendering implementation in JavaScript acting as a proof-of-concept reveals critical issues related to the native implementation in web browsers.

Journal article: On Distance Dependence of Pinna Spectral Patterns in Head-Related Transfer Functions

Year 2014 closes with good news for PADVA. The manuscript “On Distance Dependence of Pinna Spectral Patterns in Head-Related Transfer Functions” authored by Simone Spagnol  is published on the January 2015 issue of the Journal of the Acoustical Society of America (JASA, check it here), Express Letters section.


The aim of the article is to address a little understood question in sound source localization: Can the distance of a near sound source affect our own perception of its elevation? The issue is studied by means of an objective analysis of a database of distance-dependent head-related transfer functions (HRTFs) of a KEMAR mannequin with different pinnae on a dense spatial grid. Iso-directional HRTFs are compared through spectral error metrics; results indicate significant distance-dependent HRTF modifications due to the pinna occur when the source is close to the interaural axis.

BTDEI HpIR Database is now on-line for the AES Los Angeles 2014

AES137-600x360The 137th Audio Engineering Society Convention is approaching and a piece of PADVA is flying to Los Angeles with the paper “PHOnA: A Public Dataset of Measured Headphone Transfer Functions” by Braxton Boren, Michele Geronazzo, Piotr Majdak, and Edgar Choueiri. Check the PADVA’s publication page.


SOFA SingleHeadphoneIR-0.1On the occasion of this event, the PADVA project makes publicly available and hosts the BT-DEI HpIR Database which is a database of Headphones Impulse Response (HpIR) measurements for 3 different headphones and up to 24 different subjects, including the KEMAR mannequin with and without large pinnae.

The database includes 10 measurements of headphone impulse responses for each headphones and subject. These measurements were recorded at the entrance of open and blocked ear canal, OEC and BEC respectively, with Soundman OKMII Classic in-ear microphones. All the measurements are stored in bt-dei format v. 0.2 (a Matlab based data format).


Finally, we are proud to announce that the BT-DEI HpIR Database has been part of the PHOnA dataset (Princeton Headphone Open Archive) since July 2014, with the purpose of making the large amounts of existing HpTF data publicly available to researchers worldwide. All measurements are stored in SOFA data format (SimpleHeadphoneIR convention) thanks to the SOFA project and Michele’s contribution for headphone support.

Journal article: Synthetic Individual Binaural Audio Delivery by Pinna Image Processing

The manuscript “Synthetic individual binaural audio delivery by pinna image processing” authored by Simone Spagnol, Michele Geronazzo, Davide Rocchesso and Federico Avanzini is accepted for publication on the July 2014 issue of the International Journal of Pervasive Computing and Communications. The article is an extended version of the best MoMM 2013 poster award winner paper “Extraction of pinna features for customized binaural audio delivery on mobile devices”, presented at the 11th International Conference on Advances in Mobile Computing & Multimedia in December 2013, and includes results of a localization test conducted in early 2014.


The manuscript presents a system for customized binaural audio delivery based on the extraction of relevant features from a 2-D representation of the listener’s pinna. The most significant pinna contours are extracted by means of multi-flash imaging, and they provide values for the parameters of a structural head-related transfer function (HRTF) model. The HRTF model spatializes a given sound file according to the listener’s head orientation, tracked by sensor-equipped headphones, with respect to the virtual sound source. A preliminary localization test shows that the model is able to statically render the elevation of a virtual sound source better than non-individual HRTFs. The whole model has low complexity and is suitable for implementation on mobile devices, thus showing that custom binaural audio can be deployed without the need of cumbersome subjective measurements.