ACEL 

The ACoustics and ELectronics research group

Dept. of Physics, Univ. Federico II , Complesso Universitario MSA, via Cintia, I-80126 Naples, Italy

ACEL hosted International Conference on DigitalAudioEffects 2004

Phone: +39-81-676252, Fax: +39-81-676346, e-mail: ACEL@na.infn.it

Research	History	Staff
Acoustics / DSP Publications	Hearing & other DSP	Demos
Program of the DSP course	Other Publications (in related scientific areas)	Corso di Informatica Musicale
SuperB project	ISWA project	Cybernetic Theatre

you are visitor no.  since november 2002 (by )

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ACEL Group: Research Interests

The Acoustics and Electronics (ACEL) research group at University of Naples has been active in the field of acoustic signal processing for over fifteen years, promoting and performing research activities in computer music, speech and music analysis, synthesis and coding, vibration analysis and digital signal processing. These include the organization of a series of conference meetings -- the "International Workshops on Representations of Musical Signals" -- editing of specialized books, participation in international conferences on speech and music signal processing, the publication of a number of original papers in international journals and the development of hardware and software systems for acoustical signal processing. 

Active research topics are pitch-synchronous representations of pseudo-periodic signals, such as voiced sounds in speech and musical tones, and physical models of natural instruments.

The aim of the pitch-synchronous methods developed is that of representing the average periodic behavior and the fine fluctuations over this behavior into distinct components. This is useful for the analysis, synthesis and coding of audio signals in order to detect and model transients or to extract the excitation signal, such as the bow noise in a violin tone. The different components extracted form the signal call for distinct techniques of synthesis or different data-rates. Novel transforms based on frequency warping via Laguerre expansions have been defined in order to extend the pitch synchronous representations to the class of signals having unequally spaced spectral lines, such as piano and drums. 

By exploiting physical models, the sound of natural instruments may be accurately synthesized and controlled by means of few meaningful parameters. The actual differential equations or their solutions are discretized in order to design efficient algorithms suitable for a digital implementation. In particular, we developed estimation techniques for the parameters of the flexible string model (Karplus-Strong) and accurate stiff strings models based on dispersive delay lines with applications to the synthesis of piano. 

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ACEL Group: A Brief History

The ACEL group was founded in the early seventies by Giuseppe Di Giugno who started the design and realization of a modular synthesizer based on analog circuits. The synthesizer was then interfaced to a Digital PDP-11 computer. 

The system encountered the favor of several musician such as Luciano Berio. Soon Prof. Di Giugno realized that only by means of a fully digital synthesizer one could have gained total control of the overwhelming number of meaningful variables and interconnections. With the help of his students he started designing and prototyping a digital machine, the 4A synthesizer, based on fixed waveform oscillators and a fully programmable connections. 

By the late seventies G. Di Giugno was lured by IRCAM at the Centre Pompidou in Paris, where he perfectioned and expanded the design of the 4A machine, leading to the design and realization of the 4X machine. Meanwhile he appointed Prof. Aldo Piccialli as chair of the ACEL group, who was then joined by two researchers, Sergio Cavaliere and Immacolata Ortosecco, with the technical support of Pasquale Parascandolo.

The ACEL group devoted itself to the research of efficient algorithms for the synthesis of sound and to the realization of low-cost synthesizer. The leading idea was that only a large scale diffusion of the new instruments would have formed a generation of musicians able to master computer generated music. The group designed and realized several "TROLL" boards based on look-up table oscillators and multiplierless additive synthesis. By the early eighties the interest shifted towards data-reduction techniques in order to minimize the data-rate from the controlling (personal) computer to the synthesizer. A phase-modulation technique was implemented in a novel machine, the "PSOTROLL," in which the phase of each oscillator could be approximated by a piecewise linear function, requiring very few parameters in order to generate rich and realistic sounds. 

The development of this machinery gave the group the opportunity to interact with musicians who greatly contributed to the project with real-time computer music compositions. Expecially significant were the interactions with Fausto Razzi for the realization of early computer music performances and, later on, with Giancarlo Sica who is the coordinator of musical activity since 1982. He realized a number of compositions based on TROLL and PSOTROLL machines, such as "Arcana", "Timesteps" and "Cantata (ex machina)," for soprano and computer ; then based on Csound language and voice processing, works as "Kane no koe", "En sueno" , "Tsuna" and  "Particles", mainly based on granular and formant synthesis; also, based on the use of the MARS workstation by IRIS and on MAX software, some  composition based on interactive performance and real time voice processing such as "La luna" for tenor and computer.
Giancarlo Sica is also involved in the activity of a Journal on contemporary music perspectives, Konsequenz

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For the history of the ACEL group see also "Il Gruppo AC.EL. e la Computer Music in Campania,"KonSequenz, abridged version in Italian).

With the spreading of commercial synthesizers, the research interests shifted towards representations of signals for the analysis, synthesis and transmission of audio signals, based on numerical methods and transforms such as running window, granular synthesis, synthesis by analysis and wavelets. The scope of the research was extended to both speech and music, in the general setting of signal processing. 

With the external support of Gianpaolo Evangelista, who recently joined the group, several pitch-synchronous techniques were developed for the representation of pseudo-periodic sounds, including PS wavelets. The research on sound synthesis is currently focused on physical models of natural instruments. 

In March 1995 Prof. Piccialli died from heart attack in the course of one of his generous lectures. The group is motivated in pursuing the research line drawn by the late Aldo Piccialli and his original ideas, by developing novel techniques and transforms for the analysis and synthesis of signals. 

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ACEL Group: Staff

Sergio Cavaliere Sergio Cavaliere is associate professor in the Dept. of Physical Sciences at the University "Federico II" of Napoli (Italy), where he teaches Computer Architecture and Signal Processing for Multimedia in the Computer Science curriculum. Since the early 70's he has been involved in the developments of high speed special purpose hardware for real time sound and music synthesis and processing. He has also been a research associate with IRIS, Paliano, Italy, where he was involved in the design of VLSI chips for real-time sound analysis and synthesis and in the realization of the MARS workstation for sound manipulation. He has been involved in the development of algorithms for sound synthesis and manipulation and also, based on these algorithms, in the realization of a number of specialized real-time systems. Besides his main activity in digital sound and signal processing , he is also a research associate with INFN for the realization of a very-large system for data acquisition from nuclear-physics experiments and for the development of techniques for the detection of signals in high level noise. He was author or co-author of several scientific papers, mainly in the field of acoustic signal processing, specialized computers for sound processing and high-speed data acquisition systems. His current interests are in algorithms for speech and music synthesis and analysis, physical modeling of sound sources ,time-scale and wavelet representations for signal analysis and transformation, in which field his research group introduced novel approaches to wavelets. His interests are also focussed in VLSI, parallel architectures and hardware systems for sound processing. 

List of papers

Personal home page for didactical activity

cavaliere@na.infn.it

Gianpaolo Evangelista is a research associate with the Dept. of Physical Sciences at the University "Federico II" of Naples. He has also been a researcher at CEMAMU / CNET, Paris, France, where he contributed towards the development of the UPIC system for interactive sound synthesis from graphic input, and a research engineer at the Microgravity Advanced Research and Support Center, Naples, Italy, where he developed algorithms for object tracking and image velocimetry. He received the laurea in physics, summa cum laude, from the Univ. "Federico II" of Naples in 1984, and both the M.Sc. and Ph.D. from the University of California, Irvine, in 1987 and 1990, respectively. He is author or coauthor of a number of papers in the field of signal processing published in international journals, books and conference proceedings. His current interests are in signal and image processing, time-frequency representations, wavelet transforms, analysis, synthesis and coding of speech and music and theory and applications of pitch-synchronous representations. 

Curriculum vitae

evangelista@na.infn.it

Immacolata Ortosecco ---- under construction

Aldo Piccialli, was chair of the ACEL research group from the early seventies until 1995. He was an associate professor with the Dept. of Physical Sciences at the University "Federico II" of Naples. He was the author of several scientific papers in the field of acoustic signal processing and co-edited the books Representations of Musical Signals, MIT Press and Musical Signal Processing, Swets & Zeitlinger. He was a founding member of Associazione d'Informatica Musicale Italiana (AIMI) and a founding member the Interdepartmental Research Center on Signal Analysis and Synthesis (CIRASS), Naples. He died in March 1995. 

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ACEL Group: Publications

Recent papers may be found using the NEC database:   Cavaliere and Evangelista  

Books

G. De Poli, A. Piccialli and C. Roads, Eds., Representations of Musical Signals, Cambridge, MA: MIT Press, 1991. 

G. De Poli, A. Piccialli, S. Pope and C. Roads, Eds., Musical Signal Processing, Swets and Zeitlinger

, 1997. Book Description

Papers in International Journals

G. Evangelista, "Dyadic Warped Wavelets," Advances in Imaging and Electron Physics, Academic Press, vol. 117, pp. 73-171, Academic Press, April 2001. Academic Press, 2001. 

G. Evangelista, “Flexible Wavelets for Music Signal Processing,” to appear in Journal of New Music Research, vol. 30, no.1, Swets & Zeitlinger, 2001.

P. Polotti, G. Evangelista, “Fractal Additive Synthesis by means of Harmonic-Band Wavelets,” to appear in Computer Music Journal, MIT Press, Fall 2001.

G. Evangelista, S. Cavaliere, "Audio Effects Based on Biorthogonal TimeVarying Frequency Warping," Applied Signal Processing, Hindawi Publishing Co., Vol 2001 No 1,March 2001, pp. 27-35. 

P. Polotti, G. Evangelista, "Analysis and Synthesis of PseudoPeriodic 1/flike Noise by means of Wavelets with Applications Digital Audio," ," Applied Signal Processing, Hindawi Publishing Co., Vol 2001 No 1,March 2001, pp. 1-14. 

G. Evangelista, S.Cavaliere, "Discrete Frequency Warped Wavelets: Theory and Applications," IEEE Trans. on Signal Processing, special issue on Theory and Applications of Filter Banks and Wavelets, vol. 46, no. 4, pp.874-885, April 1998. Abstract

G. Evangelista, S.Cavaliere, "Frequency Warped Filter Banks and Wavelet Transform: A Discrete-Time Approach Via Laguerre Expansions," IEEE Trans. on Signal Processing, vol. 46, no.10, pp.2638-2650, October 1998. Abstract

G. Evangelista, "Comb and Multiplexed Wavelet Transforms and Their Applications to Signal Processing," IEEE Transactions on Signal Processing, vol. 42, no. 2, pp. 292-303, Feb. 1994. Abstract

G. Evangelista, "Pitch Synchronous Wavelet Representations of Speech and Music Signals," IEEE Transactions on Signal Processing, special issue on Wavelets and Signal Processing, vol. 41, no. 12, pp. 3313-3330, Dec. 1993. Abstract

G. Evangelista, "The Coding Gain of Multiplexed Wavelet Transforms," IEEE Trans. on Signal Processing, vol. 44, no. 7, pp. 1681-1692 July 1996. Abstract

S. Cavaliere, G. Evangelista and A. Piccialli, "Synthesis by Phase Modulation and its Implementation in Hardware," Computer Music Journal, vol.12, no.1,pp. 29-42 MIT Press,Cambridge,  MA:, Spring 1988.Abstract

S. Cavaliere, L. Papadia and P. Parascandolo, "From Computer Music to the Theatre: the realization of a theatrical automaton," Computer Music Journal, Cambridge, MA: MIT Press, vol 6, no.4, Winter 1982, pp.22-35. Abstract

S. Cavaliere, I.Ortosecco, P. Parascandolo, A. Piccialli, "Efficient coding for digital filters coefficients in noise measurements in PCM systems," Signal processing, North-Holland, vol. 4, nos. 5-6, October 1982, pp.375-385. Abstract

S. Cavaliere, I.Ortosecco., A. Piccialli and P. Parascandolo, "A digital IIR implementation for a psofometric weighting filter with 7 bits coefficients," Alta Frequenza, vol. L, no. 4, pp. 226-228, 1981.

S. Cavaliere, G. Di Giugno, V.Fedullo and I. Ortosecco, "A special purpose fast digital processor for Acoustical Applications," Annals of IUN, vol. XLV-XLVI, pp. 235-241, 1976-77. Abstract

Book Chapters in Edited Books

G. Evangelista, “Time and Frequency Warping of Musical Signals,” Digital Audio Effects, Wiley, in print. 

G. Evangelista, "Wavelets That We Can Play: An Update," Diderot Forum on Mathematics and Music,Computational and Mathematical Methods in Music, H. G. Feichtinger and M. Dörfler, Eds. 1999, pp. 153-168, Österreichische Computer Gesellschaft, Vienna, Austria. 

S. Cavaliere, "New generation architectures for music and sound processing," in Representation of Musical Signals, G. De Poli, A. Piccialli and C. Roads, Eds., Cambridge, MA: MIT Press, 1991, pp.391-412.Abstract

G. Evangelista, "Wavelet transforms that we can play," in Representations of Musical Signals,G. De Poli, A. Piccialli and C. Roads, Eds. 1991, pp. 119-136.MIT Press, Cambridge, MA: Abstract

G. Evangelista, "Wavelet Representations of Musical Signals," in Musical Signal Processing, Piccialli, De Poli, Roads and Pope Edts.,Swets and Zeitlinger, Amsterdam, 1997. Abstract

S. Cavaliere, A.Piccialli, "Granular Synthesis of Musical Sound," in Musical Signal Processing, Piccialli, De Poli, Roads and Pope Edts., Swets and Zeitlinger, Amsterdam, 1997.Abstract

G. Sica, "Notations and interfaces for musical signal processing," in Musical Signal Processing, Piccialli, De Poli, Roads and Pope Edts., Swets and Zeitlinger, Amsterdam, 1997. 

P. Basile, F. Cotugno, P. Maturi and A. Piccialli, "The time-scale transform method as an instrument for phonetic analysis," in Visual Representations of Speech Signals, M. Cooke, S. Beet and M. Crawford, Eds., John Wiley, 1993. 

G. De Poli and A. Piccialli, "Pitch-Synchronous Granular Synthesis," in Representations of Musical Signals, Cambridge, MA: MIT Press, 1991, pp. 187-219. 

G. Evangelista, "Wavelet Transforms and Wave Digital Filters," in Wavelets and Applications, Y. Meyer, Ed., Springer-Verlag, 1992, pp. 396-412. Paper presented at the Int. Conference on Wavelets and Applications, Marseille, France, May 1989. Abstract

Papers in Conference Proceedings

G. Evangelista, S. Cavaliere, “Analysis and Processing of Sounds by Means of the Pitch-Synchronous MDCT,” Proc. of the 14-th Colloquium on Musical Informatics, Florence, Italy, May 2003.

S.Cavaliere, G.Sica." Il gesto nella didattica Musicale," Atti del V CONVEGNO INTERNAZIONALE "Musica, Infanzia e Adolescenza", Napoli, Italy, December 2002

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S.Cavaliere, G.Sica." Granular Synthesis of Sounds: the DSP approach," Atti del Convegno Capire e Creare la Musica , Caserta, Italy, June 2001.

G. Evangelista, S. Cavaliere, "Modifying the frequency content of speech signals: a new approach," Proc. 17th ICA, International Congress on Acoustics , Roma, Italy, Sept. 2001. 

G. Evangelista, "Real-Time Time-Varying Frequency Warping via Short-Time Laguerre Transform," Proc. of DAFx 2000, Verona, Italy, pp. 7-12, Dec. 2000. 

P. Polotti, G. Evangelista, "Harmonic-Band Wavelet Coefficient Modeling for Pseudo-Periodic Sound Processing", Proc. of DAFx 2000, Verona, Italy, pp. 103-108, Dec. 2000.

G. Evangelista, S.Cavaliere,"Signal Transforms for the Detection and Identification of Signals", Proc. of the European Signal Processing Conference, EUSIPCO 2000, Tampere, Finland Sept. 2000. 

Cavaliere S., G.Evangelista, G.Sica. "Teaching Music and Acoustics : interaction by use of sensors in a Virtual Music Zone" Proceedings of the XIII CIM 2000 L'Aquila, settembre 2000.

G. Evangelista, S. Cavaliere, "Representation and Modification of Time-Varying Sound Signals," Proc. of the 13-th Colloquium on Musical Informatics, L'Aquila, Italy, pp. 25-28, Sept. 2000.

G. Evangelista. “The Short-Time Laguerre Transform: a New Method for Real-Time Frequency Warping of Sounds” Proc. of the ICMC 2000 (Internat. Computer Music Conference) pp. 380-383, Berlin, Germany,August 2000.

P. Polotti, G. Evangelista, "Time-Spectral Modeling of Sounds by Means of Harmonic-Band Wavelets," Proc. of the Internat. Computer Music Conference, ICMC 2000, Berlin, Germany, pp. 388-391, Aug. 2000.

S.Cavaliere, G.Evangelista, G.Sica." Didattica della musica: un sistema basato su controlli gestuali," Proc. of the XXVIII Convegno Nazionale dell'AIA (Associazione Italiana di Acustica) , Trani, Italy, June 2000.

G. Evangelista, S.Cavaliere, "Time-Varying Frequency Warping: Results and Experiments" Proc. of the Digital Audio Effects Workshop, DAFx99,pp. 13-16, Trondheim, Norway, Dec.1999. 

P.Polotti, G. Evangelista, "Dynamic Models of Pseudo-Periodicity," Proc. of the Digital Audio Effects Workshop, DAFx99,pp. 147-150, Trondheim, Norway, Dec.1999. 

G. Evangelista, S.Cavaliere, "On Asymptotic Properties of Frequency Warped Wavelets," Proc. of IASTED-SIP International Conference Signal and Image Processing, pp.338-342, Nassau, The Bahamas, Oct.1999 . 

S.Cavaliere, G. Evangelista,  "Unitary transform and modification of sound," Proc. of the workshop "Sistemi Intelligenti per l'Arte e l'intrattenimento" Napoli, Italy, Aprile 1999 appeared on Notizie AIIA, Sept. 1999.Abstract

S.Cavaliere, G.Evangelista." Disarmonicità di suoni da corde vibranti in presenza di rigidità del mezzo: Caratterizzazione Quantitativa e classificazione," Proc. of the XXVII Convegno Nazionale dell'AIA (Associazione Italiana di Acustica) pp.37-40 ,Genova, Italy, May 1999.

G.Evangelista, S.Cavaliere " Banchi di filtri e trasformazioni di frequenze basate su modelli uditivi," Proceedings of the XXVII Convegno Nazionale dell'AIA (Associazione Italiana di Acustica) pp.272-277,Genova, Italy, May 1999.

G. Evangelista, S.Cavaliere, "Dispersive and Pitch-Synchronous Processing of Sounds," Proc. of the Digital Audio Effects Workshop, DAFx98, pp. 232-236, Barcelona, Spain, Nov. 1998. Abstract

G. Evangelista, P. Polotti,  "Analysis and Synthesis of Pseudo-periodic 1/f-like Noise by means of Multiband Wavelets," Proc. of the XII CIM Colloquio di Informatica Musical, pp.35-38, Gorizia, Italy, Sept. 1998. 

S.Cavaliere,G. Evangelista,  "Optimum Frequency Warping of Pseudo-Periodic Signals," Proc. of the XII CIM Colloquio di Informatica Musical, pp.31-34, Gorizia, Italy, Sept. 1998. Abstract

G. Evangelista, S.Cavaliere, "Arbitrary Bandwidth Wavelet Sets," Proc. of IEEE Internat. Conference on Acoustics, Speech and Signal Processing, ICASSP'98, vol. III, pp. 1801-1804, Seattle (Washington), May 1998, Abstract

G. Evangelista, S.Cavaliere, "Auditory Modeling via Frequency Warped Wavelet Transform," Proc. of the European Signal Processing Conference, EUSIPCO '98, vol. I, pp.117-120,Rhodes, Greece, sept. 1998. Abstract

S.Cavaliere, G. Evangelista, "Representation of Pseudoperiodic Signals by means of Pitch-Synchronous Frequency Warped Wavelet Transform", Proc. of the European Signal Processing Conference, EUSIPCO 98,vol II, pp.625-628, Rhodes, Greece, Sept. 1998. Abstract

G. Evangelista, S.Cavaliere, "Analysis and Regularization of Inharmonic Sounds via Pitch-Synchronous Frequency Warped Wavelets," Proc. of the Interanat. Computer Music Conference, ICMC '97, ,pp. 51-54, Thessaloniki, Greece, Sept.1997. Abstract

I. Testa, G. Evangelista and S. Cavaliere, "A Physical Model of Stiff Strings," Proc. of the Internat. Symp. on Music and Acoustics, ISMA'97, pp. 219-224 Edinburgh, U.K., Aug. 1997 . Abstract

G. Evangelista, S.Cavaliere, "The Discrete-Time Frequency Warped Wavelet Transform," Proc. ofIEEE Internat. Conference on Acoustics, Speech and Signal Processing,ICASSP '97,vol. III 2105-2108, Munich, Germany, April 1997. Abstract

I. Testa, S.Cavaliere, G.Evangelista. "Sintesi delle corde vibranti: algoritmi basati su un modello dispersivo".Proceedings of the XXV Convegno AIA (Associazione Italiana di Acustica), pp.81-88. Perugia, Italy, 1997.

S.Cavaliere, G.Evangelista. "Una Tecnica di Analisi e Sintesi dei Segnali Acustici Pseudoperiodici mediante Trasformate Wavelet e Deformazioni Spettrali di Laguerre". Proceedings of the XXV Convegno AIA (Associazione Italiana di Acustica), pp.39-46. Perugia, Italy 1997. 

G. Evangelista, "Pseudo-Periodic 1/f-Like Noise," Proc. of the IEEE Internat. Symposium on Time-Frequency and Time-Scale (TFTS'96), pp. 121-124, Paris, France, June 1996. Abstract

S. Cavaliere, G. Evangelista,  "Deterministic Least Squares Estimation of the Karplus-Strong Synthesis Parameter," Proc. of the International Workshop on Physical Model Synthesis, pp15-19, Firenze, Italy, June 1996 

S. Cavaliere, G. Evangelista, L. Romano."Un nuovo metodo di analisi e stima dei parametri per la sintesi di suoni mediante algoritmo Karplus-Strong," Proceedings of the XXIV Convegno AIA (Associazione Italiana di Acustica), pp.197-200. Trento, Italy, June 1996.

G.Frattini,S. Cavaliere ,G. Evangelista, "Sintesi Granulare delle Consonanti Fricative Sorde". Proceedings of the XXIV Convegno AIA (Associazione Italiana di Acustica) pp. 123-126. Trento, Italy, June1996.

S. Cavaliere, G. Evangelista, I. Ortosecco, A. Piccialli  "PSOTROLL : A new synthesis Technique and Related Hardware," Proc. dell' XI Colloquio d' Informatica Musicale, pp. 85-88, Bologna, Italy, Nov. 1995. Abstract

A. Piccialli et al., "Implementation of Signal Processing Algorithms," in Parallel Computing: Methods and Applications, P. Messina and A. Murli (eds.), Elsevier Science, 1992. 

S. Cavaliere, I. Ortosecco and A. Piccialli. "Modifications of natural sounds using a pitch synchronous approach," in Proc. of the 2-nd International Workshop on Models and Representations of Musical Sounds, Capri, Italy,  Casalini Ed., 1992. 

S. Cavaliere, G. Di Giugno and E. Guarino, "Mars : the X20 device and SM1000 board," in Proc. of the International Computer Music Conference, San Jose, CA, pp. 348-351, 1992. Abstract

G. Evangelista, "Multiplexed Wavelet Transforms for the Representation of Musical Signals," Proceedings of the 2-nd Workshop on Representations of Musical Sounds, Capri, Italy, Casalini Ed., Oct. 1992. Abstract

G. Evangelista, "Time-scale representations of musical signals," Proc. of IX Colloquio d' Informatica Musicale, pp. 303-313, Genova, Italy, Nov. 1991. Abstract

G. Evangelista, A. Piccialli, "Trasformate Discrete Tempo-Scala,". Proceedings of the XIX Convegno AIA (Associazione Italiana di Acustica) pp. 401-407, Napoli, Italy, April 1991.

A. Piccialli, P.Basile, G. Evangelista, S.Vergara "Rappresentazione Tempo-Frequenza dei Segnali Digitali Basati sulle Trasformazioni Tempo-Scala ," Proceedings of the XIX Convegno AIA (Associazione Italiana di Acustica) pp. 455-458, Napoli, Italy, April 1991.

G. Evangelista and C. W. Barnes, "Discrete-Time Wavelet Transforms and Their Generalizations," invited paper at IEEE-ISCAS'90, International Symposium on Circuits and Systems, Proceedings of ISCAS'90 , New Orleans, LA, May 1990. Abstract

G. Evangelista, "Orthogonal Wavelet Transforms and Filter Banks," IV Multidimensional Signal Processing Workshop, Pacific Grove, CA, September 1989. 

G. Evangelista, "Orthogonal Wavelet Transforms and Filter Banks," Proceedings of the 23-rd Asilomar Conference, Pacific Grove, CA, November 1989. Abstract

G. Evangelista, "Discrete-Time Wavelet Transforms," Ph.D. dissertation at Univ. of California, Irvine, June 1990. Abstract

S. Cavaliere, "A general testbed for signal flow graph, connection and systolic architectures for digital signal processing," in Proc. of Signal Processing IV, EURASIP '88 , North Holland, pp.903-906, 1988. Abstract

S. Cavaliere, "New Generation architectures for DSP," in Proc. of the 1-st International Workshop on Models of singing voice and musical sound, Sorrento (Italy), 1988. 

S. Cavaliere, I. Ortosecco, A. Piccialli. "Sintesi per formanti : Controllo mediante modulazione di fase". Proc. of the VII Colloquio di Informatica Musicale. Roma 1988.

S. Cavaliere, I. Ortosecco and A. Piccialli, "Syntesis by formants: a new approach," in Proc. of the 1986 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, pp. 179-184, La Paltz, NY, 1986. Abstract

S. Cavaliere and A. Piccialli, "Phase modulation with interpolated time functions: a powerful algorythm for sound synthesis," in Proc. of the 12-th International Computer Music Conference, pp. 293-297, The Hague, Holland, 1986. Abstract

S. Cavaliere, I. Ortosecco and A. Piccialli, "Digital Noise Measurements on telephone networks," in Proc. of Noise Control '85, pp. 179-184, Cracow, Poland, 1985 

S. Cavaliere, G. Evangelista, I. Ortosecco and P. Piccialli, "Digital Signal Processing aspects in the synthesis of audio signals," in Proc. of the XXXII Open Seminar on Acoustics, pp. 325-334, Cracow, Poland,1985 

S. Cavaliere, G. Evangelista, I. Ortosecco, A. Piccialli. "Una tecnica di sintesi per modulazione di fase : sviluppi," Proc. of the VI Colloquio di Informatica Musicale. pp. 186-194, Napoli, Italy, Oct. 1985.

S.Cavaliere, G. Evangelista, I. Ortosecco, A. Piccialli, "PSOTROLL: A New Synthesis Technique and Related Hardware," Proc. of the Internat. Computer Music Conference, ICMC '94, Paris, France, Oct.1984. 

S. Cavaliere, I. Ortosecco, P. Piccialli, E. Sassi. Didattica della musica: un sistema basato su personal. Proc. of the Congresso annuale dell' AICA (Associazione Italiana di Calcolo Automatico), vol. II pp.245-249. Napoli, settembre 1983.

S. Cavaliere, I. Ortosecco, P. Parascandolo and A. Piccialli, "An efficient method to implement amplitude modulation: an hardware realization," in Proc. of the International Computer Music Conference, Venice, Italy, Sept. 1982. 

S. Cavaliere, I. Ortosecco, P. Parascandolo, A. Piccialli. "Un sistema hardware per la sintesi ed il trattamento dei segnali acustici," Proc. of the Congresso annuale dell' AICA (Associazione Italiana di Calcolo Automatico), pp.407-413.Padova, ottobre 1982.

S. Cavaliere, I. Ortosecco, A. Piccialli, S. Vergara. "Un banco microprogrammato di oscillatori," Proc. of the IV CIM Colloquio di Informatica Musicale, a cura del CNUCE CNR, pp.88-102. Pisa (Italy) dicembre 1981.

S. Cavaliere, L. Papadia. "Informatica, Musica, Teatro : Progetto di Teatro Cibernetico," Proc. of the IV CIM Colloquio di Informatica Musicale, a cura del CNUCE CNR.Pisa (Italy) pp.323-335. Dicembre 1981.

S. Cavaliere, G. Di Giugno, V. Fedullo, I. Ortosecco. "Un calcolatore veloce orientato per la sintesi di segnali acustici in tempo reale," Proc. of  I Colloquio su : Aspetti teorici di Informatica Musicale. Milano (Italy) dicembre 1977.

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ACEL Group: Audio Demo Files

The following are audio files in the AU format: 

The following example was obtained by means of pitch synchronous wavelet representation. The harmonic and inharmonic (bow noise) components correspond, respectively, to the regular trend (scaling component) and fluctuations (wavelet components) 

violin | violin harmonic component | violin inharmonic component

However, piano and other string instruments may produce sounds whos harmonics are not equally spaced, a dispersive effect due to stiffness. In this case one needs to perform a more complex operation in order to separate the "harmonic" component from transients (hammer noise). The following example was obtained by means of frequency warped pitch synchronous wavelet transform. 

piano | piano harmonic component | piano inharmonic component

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