Natural Language Engineering 1 (1): 000–000. Printed in the United Kingdom c  1998 Cambridge University Press 1 Finite-state models for Speech-based Search on Mobile Devices Taniya Mishra and Srinivas Bangalore AT&T Labs-Research 180 Park Ave Florham Park, NJ 07932 ( Received 24 September 2010 ) Abstract In this paper, we present techniques that exploit finite-state models for voice search appli- cations. In particular, we illustrate the use of finite-state models for encoding the search index in order to tightly integrate the speech recognition and the search components of a voice search system. We show that the tight integration mutually benefits Automatic Speech Recognition and improves the search. In the second part of the paper, we discuss the use of finite-state techniques for spoken language understanding, in particular, to seg- ment an input query into its component semantic fields so as to improve search as well as to extend the functionality of the system and be able to execute the user’s request against a backend database. 1 Introduction Mobile devices have revolutionized access to information. Information access has moved from desktop and laptop computers in office and home environments to be an any place, any time activity due to mobile devices. Mobile devices are pervasive due to their ability to access unlimited amount of information, almost everywhere, through the Internet. Even so, information access using text input on mobile devices with small screens and soft/small keyboards is tedious and unnatural. In addition, by the mobile nature of these devices, users often like to use them in hands-busy environments, ruling out the possibility of typing text. Therefore it might be expected that spoken utterances provide a more natural and less cumbersome modality for accessing information using mobile devices. A second issue we address in this paper is to shorten the time needed to satisfy the user’s information need. The current approach of information access involves a user typing in a query using keywords to a search engine, browsing the returned results on the small screen to select a potentially relevant document, suitably magnifying the screen to view the document and searching for the answer to her question in the document. By providing a method for the user to pose her query in natural