Stephen D. Voran

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The Institute for Telecommunication Sciences (ITS) has developed an objective video quality assessment system that emulates human perception. The system returns results that agree closely with quality judgements made by a large panel of viewers. Such a system is valuable because it provides broadcasters, video engineers and standards organizations with the(More)
Part I of this paper describes a new approach to the objective estimation of perceived speech quality. This new approach uses a simple but effective perceptual transformation and a distance measure that consists of a hierarchy of measuring normalizing blocks. Each measuring normalizing block integrates two perceptually transformed signals over some time or(More)
The value or harm associated with an increase in speech coding quality depends on the type of the increase as well as the temporal location of the increase in an utterance. For example, some increases in speech coding bandwidth can be perceived as impairments. The higher quality associated with the wider bandwidth can offset the impairment, but only if the(More)
Over the past decade, advances in digital information transmission, switching, processing, and storage technologies have created the potential for a global information infrastructure that could empower enterprises and enrich societies worldwide. Paradoxically, the same technology advances have created a bewildering overabundance of product alternatives and(More)
In advanced heterogeneous telecommunication networks, network resources can dynamically dictate the type of speech coding that is used. An increase in resources allows for lower coding distortion or it might also be used to provide wideband speech instead of narrowband speech. Existing studies have demonstrated that wideband speech is preferred to(More)
We present an objective estimator of speech intelligibility that follows the paradigm of the Modified Rhyme Test (MRT). For each input, the estimator uses temporal correlations within articulation index bands to select one of six possible words from a list. The rate of successful word identification becomes the measure of speech intelligibility, as in the(More)
Perceived speech quality is most directly measured by subjective listening tests. These tests are often slow and expensive, and numerous attempts have been made to supplement them with objective estimators of perceived speech quality. These attempts have found limited success, primarily in analog and higher-rate, error-free digital environments where speech(More)
ITU-T Recommendation P.861 describes an objective speech quality assessment algorithm for speech codecs [1]. This algorithm transforms codec input and output speech signals into a perceptual domain, compares them, and generates a noise disturbance value, which can be used to estimate perceived speech quality. The performance of this algorithm can be judged(More)