Cross-Language Speech Retrieval: Establishing a Baseline Performance

We present here the realisation of a cross-language speech retrieval system which retrieves German speech documents in response to user queries specified as French text. This has been achieved through the integration of two existing modules of the SPIDER information retrieval system, namely the query pseudo-translation module and the speech retrieval module. Our approach to cross-language retrieval uses an automatically constructed corpus-based information structure called a similarity thesaurus. A similarity thesaurus can be constructed over any loosely comparable corpus - a parallel corpus is not necessary. The similarity thesaurus used here was constructed over a 330 MByte corpus of comparable German and French news stories. Our speech retrieval module is based on a speaker-independent phoneme recognizer and it indexes speech documents by N-grams of phonemic features. The speech retrieval module includes an additional probabilistic matching technique designed to aid retrieval from e..