Language portability of a speech understanding system

Abstract

An important problem in automatic speech understanding is the transport of an existing application system to a new language. Design choices are required to keep the cost and implementation time of the porting as low as possible. One of the bottlenecks in spoken language system development is represented by data collection. When moving an application from the original language to a new one, it is very important to exploit, as much as possible, the data collected in the first language. This paper discusses the construction of a speech-based Air Travel Information Service (ATIS) for Italian, starting from (American) English. The aim of the work is to maximize the use of data available in English for the ATIS task in the construction of the Italian system. All components will be examined and proposed strategies will be evaluated by experimental tests. By just using a small Italian corpus and the ATIS data available in English, an understanding error rate of 6·7% was obtained on Italian written transcriptions. By adapting to speakers acoustic models and by training a language model on translations of transcriptions, an understanding error rate of 17·9% was obtained by considering read as well as spontaneous Italian sentences.