Auditory BCIs for Visually Impaired Users: Should Developers Worry About the Quality of Text-to-Speech Readers

Abstract. Auditory-based brain-computer interfaces (BCI) have been gaining significant grounds recently, particularly for visually impaired users. The majority of existing auditory BCIs are based on P300 auditory event related potentials. Previous studies have shown, however, that P300s may be affected by the quality of the presented speech stimuli. Since visually impaired users commonly rely on text-to-speech (TTS) readers to e.g., navigate websites and read documents, this study investigated if the quality of the TTS system had an effect on observed P300 amplitudes. An experiment with 14 healthy subjects showed that indeed TTS synthesizer quality plays a significant effect on P300 amplitude. Hence, it is recommended that auditory BCI developers pay careful attention to the quality of the TTS system commonly utilized by the user, as low-quality systems may negatively affect BCI performance