Research

Why the graphic tablet ?

A major component of the Cantor Digitalis is its interface. Several criteria are considered for the selection of the control interface.

First, as a reactive musical instrument, the latency must be less than the perception threshold, as control gestures are planned and not only selection gestures. The time resolution of the Wacom Intuos 5M tablets is 5 ms with a pen and 20 ms with a finger, and the USB time transmission of the data to the computer is negligible. Here are the conditions to get the illusion that the sound and the gesture are related by a direct causality, like in an acoustical instrument.

Second, the interface must perform a high spatial resolution to allow the continuity of the control gesture to avoid hearing the quantification steps. Wacom Intuos 5M tablets have a spatial resolution of 5080 lines per inch (0.005 mm) and 2048 levels of pressure, which is far higher than what a graphic tablet pen can reach (limited by the diameter of the pen tip and the small amplitude of the pen tip spring).

Lastly, a synthetic sound is all the more realistic than its parameters are not static. Hence the interface must allow a precise, repeatable, intuitive and constantly dynamic gesture. The pen tablet, initially designed for computer drawing, meets these criteria by using a gesture known by all and practiced since the childhood. Compared to mouse or trackpad, the tablet offers the possibility of playing subtle modulations of parameters, essential for the sound quality. The touch technology takes advantage of a new but spreader and spreader use of fingers on phones and computer tablets.

Nevertheless, to get an overview of the system without possessing a graphic tablet, the software proposes a control with mouse and keyboard.

The synthesizer

Cantor Digitalis is a performative parametric voice synthesizer. It implements the linear acoustic source-filter model of voice production. The "filter" or "vocal tract" part of the system is computed using a parallel structure made of digital second-order resonators. Vowels are controlled according to synthesis rules. The "source" or "glottal flow derivative" part of the system is computed using a linear model. The parameters are combined for controlling six vocal dimensions: pitch, voice tension, breathiness, roughness, laryngeal mechanisms, and vocal effort. CantorDigitalis includes presets for voice categories (baritone, tenor, alto, soprano), voice range profiles, source-filter interactions (formant and harmonic tuning), high F0 resolution, vocal tract size, vocalic space and voice quality control.

Related scientific publications

PhD Thesis

O. Perrotin
Chanter avec les mains: Interfaces chironomiques pour les instruments de musique numériques
PhD Thesis, Université Paris-Sud, 2015, (.pdf )
L. Feugère
Synthèse par règles de la voix chantée contrôlée par le geste et applications musicales
PhD Thesis, Université Pierre et Marie Curie (UPMC), 2013, (.pdf )
S. Le Beux
Contrôle gestuel de la prosodie et de la qualité vocale
PhD Thesis, Université Paris Sud, 2009. (.pdf)

Journal papers

L. Feugère, C. d’Alessandro, B. Doval, O. Perrotin
Cantor Digitalis: Chironomic Parametric Synthesis of Singing
EURASIP Journal on Audio, Speech and Music Processing, in edition.
O. Perrotin, C. d'Alessandro
Seeing, listening, drawing: interferences between sensorimotor modalities in the use of a tablet musical interface
ACM Transactions on Applied Perception (TAP), 14(2), 2016. (.pdf)
O. Perrotin, C. d'Alessandro
Target Acquisition vs. Expressive Motion: Dynamic Pitch Warping for Intonation Correction
ACM Transactions on Computer-Human Interactions (TOCHI), 23(3), 2016. (.pdf)
L. Feugère, C. d'Alessandro
Gestural control of voice synthesis: the Cantor Digitalis and Digitartic instruments
Traitement du signal, 32(4), 2015, 417-442. (.pdf)
C. d’Alessandro, L. Feugère, S. Le Beux, O. Perrotin, A. Rilliard
Drawing melodies: Evaluation of Chironomic Singing Synthesis
J. Acoust. Soc. Am., 135(6), 2014, 3601-3612. (.pdf)
C. d'Alessandro, A. Rilliard, S.Le Beux
Chironomic stylization of intonation
J. Acoust. Soc. Am., 129(3), 2011, 1594-1604. (.pdf)
N. d'Alessandro, P. Woodruff, Y. Fabre, T. Dutoit, S. Le Beux, B. Doval, C. d'Alessandro
Real time and accurate musical control of expression in singing synthesis
Journal on Multimodal User Interfaces, 1(1), pp. 31-39, 2007. (.pdf)

Conferences and workshop proceedings

O. Perrotin, C. d'Alessandro
Quel ajustement de hauteur mélodique pour les instruments de musique numériques ?
Journées d'Informatique Musicale (JIM15), Faculté de Musique, Université de Montreal, QC, Canada, May 7-9, 2015. (.pdf)
O. Perrotin, C. d'Alessandro
Visualizing Gestures in the Control of a Digital Musical Instrument
Proceedings of the 2014 International Conference on New Interfaces for Musical Expression (NIME14), Goldsmiths, University of London, UK, June 30-July 4, 2014, pp. 605-608. (.pdf)
O. Perrotin, C. d'Alessandro
Adaptive mapping for improved pitch accuracy on touch user interfaces
Proceedings of the 2013 International Conference on New Interfaces for Musical Expression (NIME13), Daejeon + Seoul, Korea Republic, May 27-30, 2013, pp. 186-189. (.pdf)
L. Feugère, C. d'Alessandro, B. Doval
Performative voice synthesis for edutainment in acoustic phonetics and singing: a case study using the Cantor Digitalis
5th International ICST Conference, INTETAIN, Mons, Belgium, July 3-5, 2013. In Intelligent Technologies for Interactive Entertainment, Vol. 124, 169-178, 2013, Revised Selected Papers. Springer 2013 Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. ISBN 978-3-319-03891-9.) (.pdf)
L. Feugère, S. Le Beux, C. d'Alessandro
Chorus digitalis: polyphonic gestural singing
1st International Workshop on Performative Speech and Singing Synthesis (P3S 2011), Vancouver, Canada, March 14-15, 2011, 4p. Unreferenced printed proceedings. (.pdf)
S. Le Beux, L. Feugère, C. d'Alessandro
Chorus digitalis: experiment in chironomic choir singing
12th Annual Conference of the International Speech Communication Association (INTERSPEECH 2011), Firenze, Italy, August 27-31, 2011, 2005-2008. ISSN 1990−9772. (.pdf)
N. d'Alessandro, C. d'Alessandro, S. Le Beux, B. Doval
Real-time calm synthesizer: new approaches in hands-controlled voice synthesis
Proceedings of the 6th International Conference on New Interfaces for Musical Expression (NIME'06), pp. 266-271, 2006. (.pdf)
C. d'Alessandro, N. D'Alessandro, S. Le Beux, B. Doval
Comparing time domain and spectral domain voice source models for gesture controlled vocal instruments
Proceedings of the 5th International Conference on Voice Physiology and Biomechanics, pp. 49-52, Tokyo, July 12-14, 2006 (.pdf)
C. d’Alessandro, N. d’Alessandro, S. Le Beux, J. Simko, F. Cetin, and H. Pirker
The speech conductor: Gestural control of speech synthesis
Technical Report Final Project Report #6, eNTERFACE’05, Mons, Belgium, July-August 2005. (.pdf)
B. Doval, C. d’Alessandro, and N. Henrich
The voice source as a causal/anticausal linear filter
In ISCA, editor, Proceedings of Voqual’03: Voice Quality: Functions, analysis and synthesis, Geneva, Switzerland, 2003. (.pdf)

Prizes

C. d'Alessandro, B. Doval, L. Feugère, S. Le Beux, O. Perrotin
First prize of the Margaret Guthman musical instrument competition
Margaret Guthman musical instrument competition, Atlanta, GA, USA, February 19-20, 2015.
C. d'Alessandro, B. Doval, L. Feugère, S. Le Beux, O. Perrotin
Finalists of the international competition on musical software (Lomus) of AFIM
Journées d'informatique musicale, Bourges, France, May 23, 2014.