Download Fast Sinusoid Synthesis for MPEG-4 HILN Parametric Audio Decoding Additive sinusoidal synthesis is a popular technique for applications like sound synthesis or very low bit rate parametric audio decoding. In this paper, different algorithms for the efficient synthesis of sinusoids on general purpose CPUs as found in today’s PCs are investigated. Fast algorithms for time domain synthesis of constant and linearly changing frequencies are presented and compared to frequency domain synthesis approaches. Execution time and accuracy (SNR) of the algorithms are reported for different CPU types. Finally, the algorithms are implemented in a fast MPEG-4 HILN parametric audio decoder in order to evaluate their performance in a real world application.
Download From Lossy to Lossless Audio Coding Using SPIHT This paper discusses the design and implementation of a scalable audio compression scheme that scales up from lossy to lossless compression. Scalable audio compression has been of interest in the audio compression community for some time, with the most obvious attempt at obtaining a solution coming in the form of the MPEG-4 standard [1]. At the same time the increase in bit rates in both mobile communications [2] and the internet’s broadband technology means that audio compression algorithms with higher bit rates than currently used, such as MPEG’s mp3 [1], can be employed to obtain higher quality. However, the new increased data rates are not necessarily constant, this is especially the case when considering the internet. As such, scalable schemes that can scale to lossless compression have become rather interesting from an application point of view. The scheme presented in this paper achieves lossless compression that is comparable with the state of the art whilst maintaining a scalable embedded bitstream.
Download Measuring Sensory Consonance by Auditory Modeling A current model of pitch perception is based on cochlear filtering followed by a periodicity detection. Such a computational model is implemented and then extended to characterise the sensory consonance of pitch intervals. A simple scalar measure of sensory consonance is developed, and to evaluate this perceptually related feature extraction the consonance is computed for musical intervals. The relation of consonance and dissonance to the psychoacoustic notions of roughness and critical bandwidth is discussed.
Download Human Perception and Computer Extraction of Musical Beat Strength Musical signals exhibit periodic temporal structure that create the sensation of rhythm. In order to model, analyze, and retrieve musical signals it is important to automatically extract rhythmic information. To somewhat simplify the problem, automatic algorithms typically only extract information about the main beat of the signal which can be loosely defined as the regular periodic sequence of pulses corresponding to where a human would tap his foot while listening to the music. In these algorithms, the beat is characterized by its frequency (tempo), phase (accent locations) and a confidence measure about its detection. The main focus of this paper is the concept of Beat Strength, which will be loosely defined as one rhythmic characteristic that could allow to discriminate between two pieces of music having the same tempo. Using this definition, we might say that a piece of Hard Rock has a higher beat strength than a piece of Classical Music at the same tempo. Characteristics related to Beat Strength have been implicitely used in automatic beat detection algorithms and shown to be as important as tempo information for music classification and retrieval. In the work presented in this paper, a user study exploring the perception of Beat Strength was conducted and the results were used to calibrate and explore automatic Beat Strength measures based on the calculation of Beat Histograms.
Download Live-Electronics Algorithms in the Multimedia Work “Swim Swan” Swim Swan is a multimedia work for clarinet, live electronics and computer graphics. The principles underlying the work are exposed and a set of sound-processing and synthesis algorithms that are used in this work are described. The issue of the control of the computer by the clarinet is emphasized. The artistic issues of such a work are addressed.
Download Investigations with the Sonic browser on two of the perceptual auditory dimensions of sound objects: Elasticity and force The Sonic Browser is a software tool developed especially for navigating among sounds in a 2-D space, primarily through listening. It could be used for managing large collections of sounds, but now it is turning out to be useful also for conducting psychophysical experiments, aiming at investigating perceptual dimension scaling of sounds. We used it for analyzing the relationship between the physical parameters involved in the sound synthesis and for studying the quality of the sounds generated by the SOb models. Some experiments in this direction have been already reported [1, 2], examining real and model generated sounds of impacts and bounces of objects made with different materials. In this paper, we introduce our further investigations, by analyzing perceptually the impacts and bounces sounds from a different perspective, focusing on other two perceptual dimensions, i.e elasticity of the event and the force applied to the dropped object. We will describe the new experiment we conducted and we will report the collected data, by analyzing the resulting perceptual evaluation spaces.
Download On the evaluation of perceptual similarity measures for music Several applications in the field of content-based interaction with music repositories rely on measures which estimate the perceived similarity of music. These applications include automatic genre recognition, playlist generation, and recommender systems. In this paper we study methods to evaluate the performance of such measures. We compare five measures which use only the information extracted from the audio signal and discuss how these measures can be evaluated qualitatively and quantitatively without resorting to large scale listening tests.
Download Independent subspace analysis using locally linear embedding While Independent Subspace Analysis provides a means of blindly separating sound sources from a single channel signal, it does have a number of problems. In particular the amount of information required for separation of sources varies with the signal. This is as a result of the variance-based nature of Principal Component Analysis, which is used for dimensional reduction in the Independent Subspace Analysis algorithm. In an attempt to overcome this problem the use of a non-variance based dimensional reduction method, Locally Linear Embedding, is proposed. Locally Linear Embedding is a geometry based dimensional reduction technique. The use of this approach is demonstrated by its application to single channel source separation, and its merits discussed.
Download Interpolation of long gaps in audio signals using the warped Burg's method This paper addresses the reconstruction of missing samples in audio signals via model-based interpolation schemes. We demonstrate through examples that employing a frequency-warped version of Burg’s method is advantageous for interpolation of long duration signal gaps. Our experiments show that using frequencywarping to focus modeling on low frequencies allows reducing the order of the autoregressive models without degrading the quality of the reconstructed signal. Thus a better balance between qualitative performance and computational complexity can be achieved.
Download Nonlinear time series analysis of musical signals In this work the techniques of chaotic time series analysis are applied to music. The audio stream from musical recordings are treated as representing experimental data from a dynamical system. Several performance of well-known classical pieces are analysed using recurrence analysis, stationarity measures, information metrics, and other time series based approaches. The benefits of such analysis are reported.