Abstract
Long-term heart rate variability (HRV) series can be described by time-variant autoregressive modelling. HRV recordings show dependence between distant observations that is not negligible, suggesting the existence of long-range correlations. In this work, selective adaptive segmentation combined with fractionally integrated autoregressive moving-average models is used to capture long memory in HRV recordings. This approach leads to an improved description of the low- and high-frequency components in HRV spectral analysis. Moreover, it is found that in the 24-h recording of a case report, the long-memory parameter presents a circadian variation, with different regimes for day and night periods.

Abstract
Multichannel audio is increasingly ubiquitous in consumer audio applications such as satellite radio broadcast systems; surround sound playback systems, multichannel audio streaming and other emerging applications. These applications often present challenging bandwidth constraints making parametric multichannel coding schemes attractive. Several techniques have been proposed recently to address this problem. Here we present a novel low bit rate five channel encoding system that has shown promising results. This technique called the Immersive Soundfield Rendition (ISR) System emphasizes accurate reproduction of multi-band temporal envelope. The ISR system also incorporates a very low over-head (blind upmixing) mode. The proposed multichannel coding system has yielded promising results for multi-channel coding in 0-12 kbps range. More information and audio demos are available at http://ww.atc-labs.com/isr.

Abstract
Bandwidth Extension has emerged as an important tool for the satisfactory performance of low bit rate audio and speech codecs. In this paper we describe the components of a novel integrated audio bandwidth extension toolkit (ABET). The ABET toolkit is a combination of two bandwidth extension tools: (i) The Fractal Self-Similarity Model (FSSM) for signal spectrum; and, (ii) Accurate Spectral Replacement (ASR). Combination of these two tools, which are applied directly to high frequency resolution representation of the signal such as the Modified Cosine Transform (MDCT), has several benefits for increased accuracy and coding efficiency of the high frequency signal components. At the same time the combination of the two tools entails a number of important algorithmic and perceptual considerations. In this paper we describe the components of the ABET bandwidth extension toolkit in detail. Algorithmic details, audio demonstrations, and, ABET configuration details are presented. Additional information and audio samples are available at http://www.atc-labs.com/abet/.

Abstract
This paper presents a new method performing real-time adaptive equalization of room acoustics in the frequency domain. The developed method obtains the frequency response of the room by means of the transparent insertion of a certain number of acoustic probe signals into the main audio spectrum. The opportunities for the insertion of tones are identified by means of a spectral analysis of the audio signal and using a psychoacoustic model of frequency masking. This enhanced version of the adaptive equalizer will be explained as well as its real time implementation on a TMS320C6713 DSP based platform. Finally the results of the acoustic tests and conclusions about its performance will be presented.

Abstract
Internet accessibility for the visually impaired community is still an open issue. Guidelines have been issued by the W3C consortium to help web designers to improve web site accessibility. However several studies show that a significant percentage of web page creators are still ignoring the proposed guidelines. Several tools are now available, general purpose, or web specific, to help visually impaired readers. But is reading a web page enough? Regular sighted users are able to scan a web page for a particular piece of information at high speeds. Shouldn't visually impaired readers have the same chance? This paper discusses some features already implemented to improve accessibility and presents a user feedback report regarding the AudioBrowser, a talking browser. Based on the user feedback the paper also suggests some avenues for future work in order to make talking browsers and screen readers compatible.

Abstract