Text-to-speech: what the research says
Douglas, K. H.; Ayres, K. M.; Langone, J.; Bell, V.; & Meade, C. (2009). Expanding literacy for learners with intellectual disabilities: The role of supported etext. Journal of Special Education Technology 24(3), 35-44.
This quasi-experimental research study, published in a peer-reviewed academic journal, investigated the effects of presentational, translational, illustrative, instructional, and summarizing supports on the reading and listening comprehension of students with moderate intellectual disabilities through a series of single subject experiments. For the purpose of this annotated bibliography only the text-to-speech results will be summarized. The participants included eight students: five attended high school, and three attended middle school. Short reading passages at the fourth grade reading level were imported into Microsoft Reader, software that provides both text-to-speech and word-by-word highlighting options. There is no mention of training on this software.
RESULTS: The results from this adapted alternating treatments design, where students were exposed to alternating conditions (i.e., text plus audio alone, and highlighted text plus audio) indicated that text-to-speech can provide students with moderate intellectual disabilities improved independent access to content housed in both narrative and informational text. However, the results also suggest that highlighting did not contribute markedly to the comprehension or reading ability of students with moderate intellectual disabilities.
Izzo, M. V., Yurick, A., & McArrell, B., & (2009). Supported eText: Effects of Text-to-Speech on Access and Achievement for High School Students with Disabilities. Journal of Special Education Technology 24(3), 9-20.
This quasi-experimental research study, published in a peer-reviewed academic journal, examined the effects of a text-to-speech screen reader program on the academic achievement of nine students in a high school resource room. The participants included seven high school students: one with a traumatic brain injury, one diagnosed with high-functioning autism, three with cognitive disabilities, one with an emotional disability and one with a learning disability. The open-source assistive technology program called CLiCk, Speak was used in this study to provide text-to-speech. The researchers providing training in how to use this text-to-speech software. A reverse research design was used and the text-to-speech intervention lasted approximately 14 weeks. A treatment fidelity checklist was used to measure adherence to the intervention project protocols.
RESULTS: The results of this study indicated the CLiCk, Speak translational support increased quiz performance with large effect sizes. Therefore, text-to-speech positively affects achievement supporting the use of text-to-speech as a translational resource for readers needing support to decode and comprehend content-area material.
Lange, A. A., McPhillips, M., Mulhern, G., & Wylie, J. (2006). Assistive software tools for secondary-level students with literacy difficulties. Journal of Special Education Technology, 21(3), 13.
This experimental research study, published in a peer-reviewed academic journal, examined the compensatory effectiveness of four assistive software tools (speech synthesis, spell checker, homophone tool, and dictionary) on literacy. For the purpose of this annotated bibliography only the speech synthesis results will be summarized. The participants included 93 students: 46 girls and 47 boys aged 14–15 years, who were at least one year behind in reading age as measured by the Group Reading Test II. The study adopted a two-factor mixed design and followed a pretest, training, posttest format. Participants were assigned to one of three groups: Assistive Software group, Microsoft Word Control group, and Full Control group. Groups were matched on IQ, reading ability, spelling ability, computer exposure, and socioeconomic status. The Assistive Software group used Read & Write Gold, Version 6 (2002), in conjunction with Microsoft Word; the Microsoft Word Control group used advanced tools in Microsoft Word; and the Full Control group accessed the tests through Microsoft Word but could not use the tools within the program. The Assistive Software group was trained on assistive software for use on the posttests, the Microsoft Word Control group was trained on assistive tools in the Microsoft Word software package for use on the posttests, and the Full Control group was not trained on software and had no assistance on the posttests. The effect of the speech synthesis assistive tool (Read & Write Gold) was assessed using a two-way mixed ANOVA with Pre-/Post-test performance as the within-subjects factor and Group as the between-groups factor.
RESULTS: Post-hoc tests comparing the Assistive Software group, Microsoft Word Control group, and Full Control group, respectively, revealed a significant improvement of approximately 8% for the Assistive Software group and no significant change for either the Microsoft Word Control group or the Full Control group. The Assistive Software group showed a significant improvement in reading comprehension using the speech synthesis tool, while the other two groups showed no improvement.
Pisha, B., & Coyne, P. (2001). Jumping off the page: Content area curriculum for the Internet age. Reading Online, 5(4).
This qualitative study was a formative evaluation of a digital prototype of a high school history book. The participants included 70 grade eleven students: 53 typical learners, 16 students with learning disabilities, and one student with a visual impairment.
RESULTS: This study revealed text-to-speech support was extremely popular with the readers with disabilities in the sample. Also, several students with no identified special needs reported they used the highlighting function of text-to-speech without the synthetic voice to support them. Another important finding was a number of students classified as typical learners chose to shut off the text-to-speech feature of the textbook.