Abstract. This paper gives a survey of the current state of ARTIC -the modern Czech concatenative corpus-based text-to-speech system. All stages of the system design are described in the paper, including the acoustic unit inventory building process, text processing and speech production issues. Two versions of the system are presented: the single unit instance system with the moderate output speech quality, suitable for low-resource devices, and the multiple unit instance system with a dynamic unit instance selection scheme, yielding the output speech of a high quality. Both versions make use of the automatically designed acoustic unit inventories. In order to assure the desired prosodic characteristics of the output speech, system-version-specific prosody generation issues are discussed here too. Although the system was primarily designed for synthesis of Czech speech, ARTIC can now speak three languages: Czech (both female and male voices are available), Slovak and German.

This paper presents part of the data collection efforts undergone within the project COMPANIONS whose aim is to develop a set of dialogue systems that will be able to act as an artificial "companions" for human users. One of these systems, being developed in Czech language, is designed to be a partner of elderly people which will be able to talk with them about the photographs that capture mostly their family memories. The paper describes in detail the collection of natural dialogues using the Wizard of Oz scenario and also the re-use of the collected data for the creation of the expressive speech corpus that is planned for the development of the limited-domain Czech expressive TTS system.

The paper gives a brief summarisation of preparation and recording of a phonetically and prosodically rich speech corpus for Czech unit selection text-to-speech synthesis. Special attention is paid to the process of two-phase orthographic annotations of recorded sentences with regard to their coherence.

Abstract. The paper discusses a hypothesis relating high quality textto-speech (TTS) synthesis in spoken dialogue systems with the concept of "uncanny valley". It introduces a "Wizard-of-Oz" experiment with 30 volunteers engaged in conversations with two synthetic voices of different naturalness. The results of the experiment are summarized and interpreted, leading to the conclusion that the TTS uncanny valley effect in dialogue systems can probably be superseded and inverted by a positive attitude of the systems' users toward new technologies.

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