Embodiments of the present invention pertain to adaptation of a corpus-driven general-purpose TTS system to at least one specific domain. The domain adaptation is realized by adding a limited amount of domain-specific speech that provides a maximum impact on improved perceived naturalness of speech. An approach for generating optimized script for adaptation is proposed, the core of which is a dynamic programming based algorithm that segments domain-specific corpus into a minimum number of segments that appear in the unit inventory. Increases in perceived naturalness of speech after adaptation are estimated from the generated script without recording speech from it.