Download Recognition Of Ellipsoids From Acoustic Cues Ideal three-dimensional resonators are “labeled” (identified) by infinite sequences of resonance modes, whose distribution depends on the resonator shape. We are investigating the ability of human beings to recognize these shapes by auditory spectral cues. Rather than focusing on a precise simulation of the resonator, we want to understand if the recognition takes place using simplified “cartoon” models, just providing the first resonances that identify a shape. In fact, such models can be easily translated into efficient algorithms for real-time sound synthesis in contexts of human-machine interaction, where the resonator shape and other rendering parameters can be interactively manipulated. This paper describes the method we have followed to come up with an application that, executed in real-time, can be used in listening tests of shape recognition and together with human-computer interfaces.
Download Computation of Nonlinear Filter Networks Containing Delay-Free Paths A method for solving filter networks made of linear and nonlinear filters is presented. The method is valid independently of the presence of delay-free paths in the network, provided that the nonlinearities in the system respect certain (weak) hypotheses verified by a wide class of real components: in particular, that the contribution to the output due to the memory of the nonlinear blocks can be extracted from each nonlinearity separately. The method translates into a general procedure for computing the filter network, hence it can serve as a testbed for offline testing of complex audio systems and as a starting point toward further code optimizations aimed at achieving real time.