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D. Rocchesso: Sound Processing
developed by Philippe Depalle, Chris Rogers and Gilles Poirot at the IRCAM
(Institut de Recherche et Coordination Acoustique-Musique) for the Apple Mac-
intosh platform. Based on a versatile FFT-based phase vocoder called SVP(which
stands for Super Vocodeur de Phase), Audiosculpt is essentially a drawing pro-
gram which allows the user to "draw" on the spectrum surface of a sound.
Time-Domain
Envelope
Current
FFT Frame
-60
Editing Regions
Spectrogram
Graphic Editing Palette
-35
Figure 9: A typical AudioSculpt session
In fig. 9, some portions of the spectrogram have been delimited and different
magnitude reductions have been applied to them.
Other applications, such as Lemur
, (running on Apple Macintoshes) [33]
or Ceres (developed by Oyvind Hammer at NoTam
) perform different sets of
operations such as partial tracking and tracing, logical and algorithmic editing,
timbre morphing, etc.
The contemporary sound designer can also benefit from tools which are
specifically designed to transform sound objects in a controlled fashion. One
such tool is SMS
(Spectral Modeling Synthesis), designed by Xavier Serra as
an offspring of his and Smith's idea of analyzing sounds by decomposing them
into stochastic and deterministic components [95] or, in other words, noise and
sinusoids. SMS uses the Short-Time Fourier Transform (STFT) for analysis,
tracking the most relevant peaks and resynthesizing from them the deterministic
component of sound, while the stochastic component is obtained by subtraction.
The decomposition allows flexible transformations of the analysis parameters,
thus allowing good-quality time warping, pitch contouring, and sound morphing.
In order to further improve the quality of transformations, extensions of the SMS
model have been proposed though not included in the distributed software yet.
Namely, a special treatment of transients has been devised as the way of getting
rid of artifacts which can easily come into play when severe transformations
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