Christopher M. White

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—This paper examines a query-by-example approach to spoken term detection in audio files. The approach is designed for low-resource situations in which limited or no in-domain training material is available and accurate word-based speech recognition capability is unavailable. Instead of using word or phone strings as search terms, the user presents the(More)
In this paper we examine an alternative interface for phonetic search, namely query-by-example, that avoids OOV issues associated with both standard word-based and phonetic search methods. We develop three methods that compare query lattices derived from example audio against a standard ngram-based phonetic index and we analyze factors affecting the(More)
This paper details the development of a Hybrid Evolutionary Algorithm for solving the Traveling Salesman Problem (TSP). The strategy of the algorithm is to complement and extend the successful results of a genetic algorithm (GA) using a distance preserving crossover (DPX) by incorporating memory in the form of ant pheromone during the city selection(More)
Constraint Dependency Grammar (CDG) is a constraint-based grammatical formalism that has a weak generative capacity b e y ond context-free grammars and supports a very exible parsing algorithm for working with feature grammarss however, the running time of the parser is O(n 4). Hence, we h a ve i n vesti-gated how to improve the running time of the parser(More)
This paper addresses the detection of OOV segments in the output of large vocabulary continuous speech recognition (LVCSR) system. First, standard confidence measures based on frame-based word-and phone-posteriors are investigated. Substantial improvement was however obtained when posteriors from two systems-strongly constrained (LVCSR) and weakly(More)
Automatic Speech Recognition (ASR) systems continue to make errors during search when handling various phenomena including noise, pronunciation variation, and out of vocabulary (OOV) words. Predicting the probability that a word is incorrect can prevent the error from propagating and perhaps allow the system to recover. This paper addresses the problem of(More)
This paper focusses on the effect of pronunciations for Out-of-Vocabulary (OOV) query terms on the performance of a spoken term detection (STD) task. OOV terms, typically proper names or foreign language terms occur infrequently but are rich in information. The STD task returns relevant segments of speech that contain one or more of these OOV query terms.(More)
Indexing and retrieval of speech content in various forms such as broadcast news, customer care data and on-line media has gained a lot of interest for a wide range of applications, from customer analytics to on-line media search. For most retrieval applications, the speech content is typically first converted to a lexical or phonetic representation using(More)
This paper investigates the impact of Constraint Dependency Grammars (CDG) on the accuracy of an integrated speech recognition and CDG parsing system. We compare a conventional CDG with CDGs that are induced from annotated sentences and template-expanded sentences. The grammars are evaluated on parsing speed, precision/coverage, and improvement of word and(More)