825 research outputs found
Search of spoken documents retrieves well recognized transcripts
This paper presents a series of analyses and experiments on spoken
document retrieval systems: search engines that retrieve transcripts produced by
speech recognizers. Results show that transcripts that match queries well tend to
be recognized more accurately than transcripts that match a query less well.
This result was described in past literature, however, no study or explanation of
the effect has been provided until now. This paper provides such an analysis
showing a relationship between word error rate and query length. The paper
expands on past research by increasing the number of recognitions systems that
are tested as well as showing the effect in an operational speech retrieval
system. Potential future lines of enquiry are also described
The relationship of word error rate to document ranking
This paper describes two experiments that examine the relationship of Word Error Rate (WER) of retrieved
spoken documents returned by a spoken document retrieval system. Previous work has demonstrated that
recognition errors do not significantly affect retrieval effectiveness but whether they will adversely affect
relevance judgement remains unclear. A user-based experiment measuring ability to judge relevance from
the recognised text presented in a retrieved result list was conducted. The results indicated that users were
capable of judging relevance accurately despite transcription errors. This lead an examination of the
relationship of WER in retrieved audio documents to their rank position when retrieved for a particular
query. Here it was shown that WER was somewhat lower for top ranked documents than it was for
documents retrieved further down the ranking, thereby indicating a possible explanation for the success of
the user experiment
Speech and hand transcribed retrieval
This paper describes the issues and preliminary work involved
in the creation of an information retrieval system that will
manage the retrieval from collections composed of both speech
recognised and ordinary text documents. In previous work, it
has been shown that because of recognition errors, ordinary
documents are generally retrieved in preference to recognised
ones. Means of correcting or eliminating the observed bias is
the subject of this paper. Initial ideas and some preliminary
results are presented
Spoken query processing for interactive information retrieval
It has long been recognised that interactivity improves the effectiveness of information retrieval systems. Speech is the most natural and interactive medium of communication and recent progress in speech recognition is making it possible to build systems that interact with the user via speech. However, given the typical length of queries submitted to information retrieval systems, it is easy to imagine that the effects of word recognition errors in spoken queries must be severely destructive on the system's effectiveness. The experimental work reported in this paper shows that the use of classical information retrieval techniques for spoken query processing is robust to considerably high levels of word recognition errors, in particular for long queries. Moreover, in the case of short queries, both standard relevance feedback and pseudo relevance feedback can be effectively employed to improve the effectiveness of spoken query processing
Robust audio indexing for Dutch spoken-word collections
Abstract—Whereas the growth of storage capacity is in accordance with widely acknowledged predictions, the possibilities to index and access the archives created is lagging behind. This is especially the case in the oral history domain and much of the rich content in these collections runs the risk to remain inaccessible for lack of robust search technologies. This paper addresses the history and development of robust audio indexing technology for searching Dutch spoken-word collections and compares Dutch audio indexing in the well-studied broadcast news domain with an oral-history case-study. It is concluded that despite significant advances in Dutch audio indexing technology and demonstrated applicability in several domains, further research is indispensable for successful automatic disclosure of spoken-word collections
Examining and improving the effectiveness of relevance feedback for retrieval of scanned text documents
Important legacy paper documents are digitized and collected in online accessible archives. This enables the preservation, sharing, and significantly the searching of
these documents. The text contents of these document images can be transcribed automatically using OCR systems and then stored in an information retrieval system. However, OCR systems make errors in character recognition which have previously been shown to impact on document retrieval behaviour. In particular relevance feedback query-expansion methods, which are often effective for improving electronic
text retrieval, are observed to be less reliable for retrieval of scanned document images. Our experimental examination of the effects of character recognition errors
on an ad hoc OCR retrieval task demonstrates that, while baseline information retrieval can remain relatively unaffected by transcription errors, relevance feedback via query expansion becomes highly unstable. This paper examines the reason for this behaviour, and introduces novel modifications to standard relevance feedback methods. These methods are shown experimentally to improve the effectiveness of relevance feedback for errorful OCR transcriptions. The new methods combine similar recognised character strings based on term collection frequency and a string edit-distance measure. The techniques are domain independent and make no use of external resources such as dictionaries or training data
Spoken content retrieval: A survey of techniques and technologies
Speech media, that is, digital audio and video containing spoken content, has blossomed in recent years. Large collections are accruing on the Internet as well as in private and enterprise settings. This growth has motivated extensive research on techniques and technologies that facilitate reliable indexing and retrieval. Spoken content retrieval (SCR) requires the combination of audio and speech processing technologies with methods from information retrieval (IR). SCR research initially investigated planned speech structured in document-like units, but has subsequently shifted focus to more informal spoken content produced spontaneously, outside of the studio and in conversational settings. This survey provides an overview of the field of SCR encompassing component technologies, the relationship of SCR to text IR and automatic speech recognition and user interaction issues. It is aimed at researchers with backgrounds in speech technology or IR who are seeking deeper insight on how these fields are integrated to support research and development, thus addressing the core challenges of SCR
Indexing, browsing and searching of digital video
Video is a communications medium that normally brings together moving pictures with a synchronised audio track into a discrete piece or pieces of information. The size of a “piece ” of video can variously be referred to as a frame, a shot, a scene, a clip, a programme or an episode, and these are distinguished by their lengths and by their composition. We shall return to the definition of each of these in section 4 this chapter. In modern society, video is ver
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