Paragraph prosodic patterns to enhance text-to-speech naturalness

Abstract

Speech synthesis has reached a reasonable high quality in recent years. However, there is still room for improvement in terms of naturalness and expressiveness when dealing with large multisentential discourse, since most text-to-speech synthesizers do not fully take into account the prosodic differences that have been observed in discourse units such as paragraphs. This work presents an implementation of paragraph-based prosodic patterns into the open-source MARYTTS platform, enriching its prosody output by means of intra- and inter-paragraph prosodic features. The set of characteristics include pitch decay, pitch range and speech rate variation (as intra-paragraph features), as well as paragraph break pauses and speech rate variation (as inter-paragraph features), previously analyzed in a large set of TED Talks and read-speech sections of the Spoken Wikipedia Corpus. The perception tests, performed both in English and German parametric voices, suggest that paragraph-based features should be further studied and taken into account on future implementations to synthesize large discourse speech.