Synthetic and Natural Speech Intelligibility in Individuals with Visual Impairments: Effects of Experience and Presentation Rate Marialena BAROUTI a , Konstantinos PAPADOPOULOS a,1 and Georgios KOUROUPETROGLOU b a Department of Educational and Social Policy, University of Macedonia, Thessaloniki, Greece c Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Greece Abstract. The present study aims to compare the intelligibility of words produced in natural and synthetic speech both with normal and fast speaking rate. The effect of several individual parameters on the intelligibility of synthetic speech was also investigated. Thirty adults with visual impairment took part in the research. The experimental design consisted of two parts: a structured interview and a psychoacoustic test. The interviews were focused on the participants’ demographic data experience in using synthetic speech. he results indicated that participants performed more accurately in recognizing words presented in normal speaking rate than in a fast rate. Moreover, the results indicated that the differences between synthetic and natural speech were statistically significant. Keywords. Visual impairments, speech intelligibility, synthetic speech. Introduction Synthetic speech perception is usually discussed in the literature with regard to intelligibility and comprehension [1]. Intelligibility is the listener’s ability to recognize phonemes and words presented in isolation [2], whereas comprehension involves the extraction of the underlying meaning from the acoustic signals of speech [3]. There is an abundance of research carried out regarding the intelligibility of synthetic speech produced by Text-to-Speech (TtS) systems experienced by non disabled people. These studies showed that the intelligibility of natural speech is significantly greater than that of TtS synthesis systems [4]. Nevertheless, limited research is available on the perception of synthetic speech by individuals who have visual impairments [5]. Stevens et al. [6] Found that the gender of the voice and the quality of the signal in TtS synthesis affect the intelligibility. Moreover, previous studies indicate that 1 Corresponding Author: Konstantinos Papadopoulos, University of Macedonia, Department of Educational and Social Policy, 156 Egnatias st., GR-54006 Thessaloniki, Greece. Tel.: +30 2310891403; Fax: +30 2310891388; E-mail: kpapado@uom.gr Assistive Technology: From Research to Practice P. Encarnação et al. (Eds.) IOS Press, 2013 © 2013 The authors and IOS Press. All rights reserved. doi:10.3233/978-1-61499-304-9-695 695