The Discrete Fourier Transform, Part 2: Radix 2 FFT

The Danielson-Lancoz lemma shows that a sequence must be divided up into its odd and even subsets. That these subsets must in-turn be divided into their subsets. This continues until we have only two members per subset

Switched Spatial Impulse Response Convolution as an Ambisonic Distance-Panning Function

Ambisonics offers a robust and effective approach to the recording, processing and delivery of Spatial Audio. The Ambisonic system is often considered to provide a perceptually and computationally advantageous Spatial Audio experience in comparison to typical Binaural systems. This is true even when an end-step Binaural render is required, as is typical in Virtual or Augmented Reality systems which naturally imply audio delivery via headphones. Standard Ambisonic processing allows for the rotation of a sound field around an origin position. There is not, however, a strongly established means of modulating the radial distance of a virtual sound source from the origin. This paper presents a potential solution to an Ambisonic distance-panning function for both static and dynamic virtual sources in the form of a FOA (First Order Ambisonics) Switched-SIR (Spatial Impulse Response) Convolution Reverberator. This includes a presentation of the framework for such a function, and an analysis of audio rendered using prototype scripts

Time-frequency Analysis of Biomedical Signals

Tato diplomová práce je zaměřena na vytvoření výukového modulu pro zkoumání metod časově-frekvenční analýzy biomedicínských signálů. V rámci práce jsou představeny základní metody analýzy biomedicínských signálů v časově-frekvenční oblasti s cílem analýzy biomedicínských signálů vykazujících frekvenční nestacionaritu. V teoretické části jsou představeny metody spektrální analýzy a vyplývající metody analýzy v časově-frekvenční oblasti. V praktické části jsou popsány demonstrační algoritmy pro výpočty frekvenčních spekter pomocí Rychlé Fourierovy transformace a je provedena analýza jejich časové výpočetní náročnosti. Pro výpočet časově-frekvenčních spekter jsou vybrány metody Krátkodobé Fourierovy transformace, Vlnkové transformace a Winger-Ville rozdělení. Jsou představeny algoritmy výpočtu těchto metod a je provedena kvantitativní analýza dynamické intenzity šumu v kontextu časově-frekvenční analýzy. V rámci práce bylo vytvořeno graficko-uživatelské prostředí pro výuku problematiky časově-frekvenční analýzy bio signálů a byla vytvořena databáze testovacích biomedicínských signálů.This diploma thesis is focused on the creation of a learning module for the investigation of time-frequency analysis methods. Basic methods of analysis of biomedical signals in time-frequency domain with are presented. In the theoretical part are introduced spectral analysis methods and time-frequency analysis methods. In the practical part are described demonstration algorithms for calculation of frequency spectra by Fast Fourier transform. An analysis of their computational complexity is performed. For calculation of time-frequency spectra, the methods of Short-time Fourier transform, Wavelet transform and Winger-Ville distribution are selected. Algorithms of calculation of these methods are presented and quantitative analysis of dynamic noise intensity in context of time-frequency analysis is performed. In this thesis a graphical-user interface for teaching time-frequency analysis of bio signals was created and a test database of biomedical signals was created.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn

Audio for Virtual, Augmented and Mixed Realities: Proceedings of ICSA 2019 ; 5th International Conference on Spatial Audio ; September 26th to 28th, 2019, Ilmenau, Germany

The ICSA 2019 focuses on a multidisciplinary bringing together of developers, scientists, users, and content creators of and for spatial audio systems and services. A special focus is on audio for so-called virtual, augmented, and mixed realities. The fields of ICSA 2019 are: - Development and scientific investigation of technical systems and services for spatial audio recording, processing and reproduction / - Creation of content for reproduction via spatial audio systems and services / - Use and application of spatial audio systems and content presentation services / - Media impact of content and spatial audio systems and services from the point of view of media science. The ICSA 2019 is organized by VDT and TU Ilmenau with support of Fraunhofer Institute for Digital Media Technology IDMT