About improving recognition of spontaneously uttered French city-names

This paper deals with the recognition of French city-names over the telephone. This recognition task, critical in many applications, involves a 40,000 city-name vocabulary, ranging from short monosyllabic words to long official compound-names. Data collected from a field experiment are analyzed, and several ways of improving speech recognition performance are investigated. This includes a careful checking of the pronunciation lexicon, acceptation of shorter forms (common names), adaptation of the acoustic models and introduction of specific noise models as well as a few frequent words and expressions to facilitate out-of-vocabulary data rejection. Experiments show that all these techniques help improving the overall recognition performances and nicely combine together.