The Evidence Behind TTS in the Classroom
A meta-analysis published in the Journal of Learning Disabilities by Wood, Moxley, Tighe, and Wagner examined 22 studies on text-to-speech and reading comprehension for students with reading disabilities. The analysis found a positive weighted effect size of d = 0.35 (95% CI [.14, .56], p < .01), with between-subject studies showing stronger effects at d = 0.61. These findings provide evidence that TTS is a meaningful support for students who struggle with decoding, not merely a convenience.
The International Dyslexia Association states that text-to-speech technology "can be as vital for students with dyslexia as a screen reader is for someone who is visually impaired." IDA recommends a dual approach that combines direct reading instruction with assistive technology access, noting that AT "has the potential to increase learner motivation, prolong focus, and build confidence." This aligns with Mote's approach of providing TTS alongside explicit comprehension tools rather than as a standalone accommodation.
Beyond students with identified disabilities, TTS supports the broader classroom through Universal Design for Learning. CAST's UDL Guidelines identify TTS as a core implementation of the principle of multiple means of representation, describing audio transformation of text as "among the most easily accomplished methods for increasing accessibility." When all students have access to Read Aloud, the tool becomes a normal part of classroom learning rather than something that singles out individual learners.