[en] Sound synthesizers are a popular instrument used to generate or emulate sounds. Unlike any other instrument, synthesizers have the unique feature to allow the direct control over the sound generation process. Although useful to explore and generate new sounds, they present a major issue: a counter-intuitive interface whose complexity is inherently linked with its sound generating capabilities and the amount of data needed to control the timbre as they expand. The usage of a synthesizer lies in two different aspects: the creation of interesting sounds and the ability to perform a musical piece with that sound. In keyboard-based synthesizers the ability to perform relies in the interface musical technique. However the ability to generate sounds is more linked to concepts such as waveform, spectrum, modulation and filtering. The peak of a performer's ability is to play while the sound is being shaped, performing and shaping the sound at the same time. Due to the control limitations previously stated, synthesizers are generally used in a "first generate, then play" sequence, this means preparing the sounds and storing them previously to be loaded and played them during the performance. This, somehow, limits synthesizer's capabilities, using only half of their potential at a time. The main objective of this project is to bring closer both sound-generation and performance processes in synthesizers, trying to avoid the "first-generate, then play" typical usage by providing an interface to allow a comfortable usage of both sides at the same time. First of all, a synthesizer is needed. Despite there are many synthesizer available (both software and hardware), they usually lack the control exhaustiveness required to access to every single synthesizer parameter with external means. For this purpose, a specific synthesizer with these accessing capabilities needs to be implemented. Different synthesis techniques are studied in order to obtain a wide range of sound generating capabilities, specifically frequency modulation, additive, subtractive and granular synthesis. Regarding granular synthesis, an approach based on machine learning is proposed in order to overcome some intrinsic issues presented by this technique. The second step is to implement an interface to enable the control of several parameters simultaneously in real time. As the usual interfaces (knob, fathers, wheels…) do not fulfil these requirements, a non-standard interface should be studied. These interfaces can provide an exhaustive control over a large number of sound synthesis parameters at the same time, enhancing the controllability of the designed synthesizer. Different technologies to develop the interface should be studied. Finally an implementation using embedded systems is proposed. The choice of embedded systems is because of its simplicity for development –due to running an operating system just as a desktop computer–, but at the same time providing the portability and packaging possibilities that lack in a personal computer, while retaining a substantial part of its computational power.

[es] Los sintetizadores de sonidos son unos instrumentos populares para generar o emular sonidos. A diferencia de cualquier otro instrumento, los sintetizadores tienen la característica única de permitir el control directo sobre el proceso de generación del sonido. Aunque son muy útiles para explorar y generar nuevos sonidos, presentan un importante problema: una interfaz poco intuitiva, la complejidad de la cual esta inherentemente ligada a las capacidades de generación sonora y a la cantidad de información necesaria para controlar el timbre. La utilización de los sintetizadores recae en dos aspectos, la habilidad de generar nuevos sonidos y la habilidad de interpretar una pieza musical con el sonido generado. En los sintetizadores basados en teclado, la habilidad de interpretar recae sobre la técnica pianística mientras que la capacidad para generar sonidos está más relacionada con conceptos como ondas, espectro, modulación y filtraje. La máxima habilidad de un intérprete es la modificación del sonido mientras interpreta una pieza. Debido a las limitaciones de control nombradas anteriormente, los sintetizadores se utilizan en una secuencia "primero generar, después interpretar". Esto significa generar y guardar previamente todos los sonidos para ser posteriormente cargados e interpretar con ellos. Esta utilización limita las posibilidades del instrumento, utilizando solo la mitad de potencial en cada instante. El objetivo de este proyecto es acercar los campos de generación de sonido y la interpretación en los sintetizadores, evitando la secuencia "primero generar, después interpretar", proveyendo una interfaz que permita una cómoda utilización los dos aspectos del instrumento al mismo tiempo. Para conseguir-lo un sintetizador es diseñado y implementado, usando técnicas de síntesis de sonido aditiva, substractiva, modulación en frecuencia y granular. Respecto a la síntesis granular se propone un procedimiento basado en aprendizaje automático para superar algunas de las limitaciones intrínsecas presentadas por esta técnica. En el segundo lugar se estudia la implementación de una interfaz de control no estándar usando distintas tecnologías. Finalmente se propone una implementación usando sistemas encastados.