The Centre for Speech Technology Research, The university of Edinburgh


Project Summary

The Spoken Output Labelling Explorer

Project Details

The SOLE project is researching ways in which to couple natural language generation (NLG) systems with Text-to-Speech (TTS) systems.


A major aspect of SOLE is to couple two existing state-of-the-art systems to form a single speech generation system. The ILEX system, developed jointly by HCRC and AI is the NLG system operating in the museum labelling domain. Festival is the speech synthesis system developed at CSTR. We expect that coupling these two systems will have a positive effect on intonation: ILEX will be able to tell Festival when it's comparing or contrasting two objects, when it's referring to old or new information, when it's using a parenthetical or starting a new paragraph, etc., and Festival will decide, based on this information, that it needs to pause, to emphasise or deemphasise, to modify its pitch range, etc.


SOLE is aimed at providing a general interface between NLG and TTS systems, but for purposes of development and demonstration we have built a domain-specific demonstrator system. Continuing the work on the ILEX project, the domain chosen is one of an automated museum guide whose purpose is to provide intelligent tailored information on exhibits. Eventually the system will be contained in a portable unit so that visitors can recieve spoken information on their tour of a Museum.

Standard Interfacing

A goal of the project is to formalise the ways in which any TTS and NLG systems can be integrated. The experience gained from the integration will be used to aid the development of a speech synthesis markup langauge, SOLEML.

Personnel (University of Edinburgh)


The project aims to develop and evaluate the effectiveness of a rhetorically-oriented language to a text-to-speech system:

Current Progress

In the first phase of the project, we:

We found that the SOLEML tags that are the most useful as predictors of accent placement are anaphora-elem (our annotation of noun phrases for syntactic, semantic and reference type) and rhet-emph (our annotation of the phrases within rhetorical structure that receive emphasis because they are constrastive, etc.). Our results are reported in the article "On the Use of Automatically Generated Discourse-Level Information in a Concept-to-Speech Synthesis System", which will appear in the Proceedings of the International Conference on Speech and Language Processing, Australia, December 1998. We are currently completing phase 1 of the project by comparing different statistical techniques for accent placement prediction and completing development of the S1 version of the SOLE system.

In the second phase of the project (beginning September 1998), we plan to improve upon our results by adding to the set of SOLEML tags and by predicting accent size and contours as well as accent placement. Specifically, we will:

Related issues

Issues that might be appropriate for other grants under the EPSRC programme include the following:


This work is being funded by the Engineering and Physical Science Research Council.
Grant reference GR/L50341
Duration: May 1997 - April 2000

Current Publications

Contact Janet Hitzeman for more details.