Download On the Use of Perceptual Properties for Melody Estimation This paper is about the use of perceptual principles for melody estimation. The melody stream is understood as generated by the most dominant source. Since the source with the strongest energy may not be perceptually the most dominant one, it is proposed to study the perceptual properties for melody estimation: loudness, masking effect and timbre similarity. The related criteria are integrated into a melody estimation system and their respective contributions are evaluated. The effectiveness of these perceptual criteria is confirmed by the evaluation results using more than one hundred excerpts of music recordings.
Download On Stretching Gaussian Noises with the Phase Vocoder Recently, the processing of non-sinusoidal signals, or sound textures, has become an important topic in various areas. In general, the transformation is done by the phase vocoder techniques. Since the phase vocoder technique is based on a sinusoidal model, it’s performance is not satisfying when applied to transform sound textures. The following article investigates into the problem using as example the most basic non-sinusoidal sounds, that are noise signals. We demonstrate the problems that arise when time stretching noise with the phase vocoder, provide a description of some relevant statistical properties of the time frequency representation of noise and introduce an algorithm that allows to preserve these statistical properties when time stretching noise with the phase vocoder. The resulting algorithm significantly improves the perceptual quality of the time stretched noise signals and therefore it is seen as a promising first step towards an algorithm for transformation of sound textures.