A digital waveguide-based approach for Clavinet modeling and synthesis

The Clavinet is an electromechanical musical instrument produced in the mid-twentieth century. As is the case for other vintage instruments, it is subject to aging and requires great effort to be maintained or restored. This paper reports analyses conducted on a Hohner Clavinet D6 and proposes a computational model to faithfully reproduce the Clavinet sound in real time, from tone generation to the emulation of the electronic components. The string excitation signal model is physically inspired and represents a cheap solution in terms of both computational resources and especially memory requirements (compared, e.g., to sample playback systems). Pickups and amplifier models have been implemented which enhance the natural character of the sound with respect to previous work. A model has been implemented on a real-time software platform, Pure Data, capable of a 10-voice polyphony with low latency on an embedded device. Finally, subjective listening tests conducted using the current model are compared to previous tests showing slightly improved results

Timbre from Sound Synthesis and High-level Control Perspectives

International audienceExploring the many surprising facets of timbre through sound manipulations has been a common practice among composers and instrument makers of all times. The digital era radically changed the approach to sounds thanks to the unlimited possibilities offered by computers that made it possible to investigate sounds without physical constraints. In this chapter we describe investigations on timbre based on the analysis by synthesis approach that consists in using digital synthesis algorithms to reproduce sounds and further modify the parameters of the algorithms to investigate their perceptual relevance. In the first part of the chapter timbre is investigated in a musical context. An examination of the sound quality of different wood species for xylophone making is first presented. Then the influence of instrumental control on timbre is described in the case of clarinet and cello performances. In the second part of the chapter, we mainly focus on the identification of sound morphologies, so called invariant sound structures responsible for the evocations induced by environmental sounds by relating basic signal descriptors and timbre descriptors to evocations in the case of car door noises, motor noises, solid objects, and their interactions

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

The epidemiology of multiple sclerosis in Devon: a comparison of the new and old classification criteria

Objectives: To determine the prevalence of multiple sclerosis in Devon and compare the new McDonald classification guidelines with the Poser criteria currently used. Methods: All patients known to have multiple sclerosis and alive and resident within the chosen area on 1 June 2001 were included in the study. Seven sources of case ascertainment were used and each patient was classified according to both the Poser criteria and the McDonald guidelines. Results: The prevalence of multiple sclerosis in Devon was 118 per 100 000 (definite and probable cases, Poser criteria) in a population of 341 796, on the prevalence day. The prevalence of definite and possible cases, as classified by the new McDonald guidelines, was slightly lower at 117 per 100 000. Clinical demographics of the prevalent population were similar to those of other studies in the United Kingdom. Conclusions: This is first survey to use the new recommended guidelines and compare these criteria with the Poser classification. The difficulties encountered with applying the new criteria in research are highlighted, as are the differences between the new and old criteria. This study reports one of the highest prevalences in the south of the UK, adding support for a north-south divide being a step effect rather than a latitudinal gradient

Synthetic Studies on the MARDI Cascade : Stereoselective Synthesis of Heterocyclic Seven-Membered

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