Sound analysis, sound synthesis, and sound processing for audio and musical applications

这项研究项目旨在通过受益于信号处理技术的最新进展来提高音频信号表示和建模的准确性和充分性。更准确地说，目标是更好地解决声音信号的双重性质，声音信号通常是时间瞬变和调制频率分量的混合。它将带来更好的声音处理和声音合成质量，并将培育高质量声源分离或音频变形等应用项目。*该项目是用于声音合成和声音处理的所谓分析/合成方法的一部分，该方法在音乐应用中经常使用，但也在声音设计、音频编码和录音中使用。分析/综合的基本目标是构思相关的模型，以通过一组控制合成结构的时间函数(控制参数)来表示声信号。这些时间函数可以抽象地生成，或者在分析过程期间从预先记录的声音中提取。重新合成产生的信号听起来与原始声音完全相同。通过修改和替换控制参数，该分析/合成方案可以提供非常精细和精确的声音材料处理。例如，它可以允许人们产生从单个原始声音派生的一系列合成声音信号，或者在两个关键声音之间执行变形。它还可以用来通过对时间函数进行适当的分类和分组来做出源分离的决定。*我们计划对复调信号的分音的时变参数进行更一般和更高级别的描述，并开发补充分析技术。我们还希望为音频源分离提供更好的策略，这将受益于对声音信号基本结构的先验知识，特别是关于相位的先验知识。最后，将分析/合成方法扩展到某些类型的非线性系统将有助于更统一地看待声音合成和声音处理，并将允许对现有的几种音频效果进行一般表示。*除了知识的进步和高素质人员的培训外，在应用方面的预期意义是，更好的分析/合成程序将导致改进的合成和处理方法。更具体地说，这种改进在少数声源分离有用的应用中可能是决定性的，例如用于录音、音频恢复、编码、游戏行业和电影音效的高级混音。它还将有助于设计涉及复杂声音混合的工业应用，如环境声音(滚动、球、风、水和马达的声音)。

This research project aims at improving the accuracy and the adequacy of audio signal representations and modelling by benefiting from recent advances in signal processing techniques. More precisely the goal is to better address the dual nature of sound signals, which are often a mixture of temporal transients, and modulated frequency components. It will result in a better quality of sound processing, sound synthesis, and will nurture applied projects such as high-quality sound source separation or audio morphing.***This project is part and parcel of the so-called analysis/synthesis approach for sound synthesis and sound processing, an often-used approach in musical applications, but also in sound design, audio coding and sound recording. The basic goal of analysis/synthesis is to conceive relevant models to represent acoustical signals by a set of temporal functions (the control parameters) that controls a synthesis structure. These temporal functions can be generated in the abstract or extracted from a pre-recorded sound during the analysis process. Re-synthesis produces a signal that sounds perceptually identical to the original sound. By modifying and substituting control parameters, this analysis/synthesis scheme can provide for very refined and precise processing of sound material. For example, it may allow one to produce a family of synthetic sound signals derived from a single original one or to carry out a morphing between two key sounds. It can also be used to make a decision on source separation by a proper sorting and grouping of temporal functions into coherent subsets.***We plan to put in place a more general and higher-level description of time-varying parameters of the partials of polyphonic signals, and develop complementary analyses techniques. We also hope to provide better strategies for audio source separation that will benefit from prior knowledge of the underlying structure of sound signals, particularly as regards the phase. Finally, the extension of the analysis/synthesis approach to some classes of non-linear-systems will contribute to a more unified view of sound synthesis and sound processing and will allow for a general representation of several existing audio effects. ***Beyond the advance of knowledge and the training of highly qualified personnel, the expected significance in terms of applications is that a better analysis/synthesis procedure would lead to refined synthesis and processing methods. More specifically, this refinement could be decisive in applications where the separation of a few sound sources is useful, such as advanced remix for sound recording, audio restoration, coding, game industry, and movie sound effects. It would also help to design industrial applications which involve mixture of complex sounds such as 'environmental sounds' (rolling, balls, wind, water, and motor sounds).