Sound examples illustrating the paper:


" Analysis-Synthesis of Impact Sounds
by Real-Time Dynamic Filtering"

Mitsuko ARAMAKI, Richard KRONLAND-MARTINET


IEEE Transactions on Audio, Speech and Language Processing
Volume 14, number 2, pages 695-705, March 2006.


  Synthesis of the material contribution (see paragraph (III.A)):
The main characteristics of an impacted material are reproduced with the model (without adding any modes).
  • 1:  Strong damping (the sound present some "wooden" characteristics)
  • 2:  Weak damping (the sound present some "metallic" characteristics)

  Simulation resultsfrom the two implementations of the synthesis  model for an arbitrary set of parameters (see paragraph (III.D)):
The dynamic filter F is arbitrarily chosen as a one pole-one zero filter. The time evolution of the synthesis parameters are shown on Figure 3. The initial white noise is filtered by a bandpass filter to take into account the impact strength of the excitator.
We arbitrarily chose to simulate five emergent modes for the two approaches (for the additive approach, a sum of five sinusoids and for the digital waveguide approach, five feedback loops).
  • 3:  Synthesis signal from the model using the additive approach (signal represented on Figure 4 (a))
  • 4:  Synthesis signal from the model using the banded digital waveguide approach (signal represented on Figure 4 (b))
The sounds generated by the two approaches are similar. An important difference between these two approaches is that for the additive
approach, the modes are obtained from a stationary signal (sinus waves) and for the banded digital waveguide approach, the modes are obtained from a non-stationary signal (white noise). Consequently, the sounds generated by the second approach seem more realistic because the deterministic part (contribution of the most prominent modes) of the signal is more correlated to the stochastic part.

To increase the realism of the sounds generated by the additive approach, we can replace the sum of sinusoids by a sum of filtered white noises centered around the frequencies of the sinusoids.
Example of synthesis signals, provided the same set of parameters:
  • 5:  Synthesis signal from the model using the additive approach with a sum of sinusoids
  • 6:  Synthesis signal from the model using the additive approach with a sum of filtered white noises
For the sound 6, the fluctuant characteristic of the filtered white noises allows the resonant part of the signal to be less separated from the noisy part.

  Sound example of impacted rectangular thin plates of various  materials (see paragraph (IV.C.1)):
The following signals were obtained experimentally by impacting rectangular thin plates.

  Example of  analysis-synthesis of an experimental signal (see paragraph (IV.C.2)):
We have resynthesized the impulse response of a piano soundboard, obtained experimentally.
The synthesis parameters were estimated from the analysis of the original signal.


  Control of the real-time synthesis model through the Radio Baton interface:
The model has been implemented in real-time using the Radio Baton interface and for our purpose, two batons are used.
With one baton, we control the evolution of the parameter to vary.
With the second baton, we lauch the sound and control the strength of the impact.


  Morphing effects, simulating the continuous transition between two materials:
Each transition is composed of 22 consecutive hybrid sounds obtained by interpolating thesynthesis parameters.
These sound examples are currently used in neurophysiological experiments to study the categorization process of impacted materials