Title: Designing Brain-computer Interfaces for Sonic Expression Authors: Satvik Venkatesh, Edward Braund, and Eduardo Reck Miranda Email: {satvik.venkatesh, edward.braund, eduardo.miranda}@plymouth.ac.uk Affiliation: Interdisciplinary Centre for Computer Music Research (ICCMR), University of Plymouth, UK 1. Introduction - Brain-computer interfaces (BCIs) are beneficial for patients who are suffering from motor disabilities [1]. - BCIs provide a communication medium that is independent of muscular control. 2. Objectives - Evaluate sound synthesis techniques to build BCI-based synthesisers based on SSVEP [2]. - Find novel ways for patients to express themselves through sound. 3. BCI-based Synthesisers Image: SSVEP-based sound synthesiser that allows the user to adjust amplitude, frequency, attack, decay, sustain, and release. 4. Sonic Expression - This study proposes a new concept called sonic expression, that is to express oneself purely through the synthesis of sound. - The degree of sonic expression is calculated by the number of spectral peaks and formant regions. 5. Evaluation - The different synthesis techniques evaluated are additive, subtractive, simple FM, MMFM, and MCFM. - They are evaluated based on two criteria: degree or sonic expression and efficiency of target utilisation. Image: A comparison of synthesis techniques. Subtractive synthesis has maximum efficiency of target utilisation and MCFM and maximum degree of sonic expression. References [1] L. F. Nicolas-Alonso and J. Gomez-Gil. Brain-computer interfaces, a review. Sensors, 12(2):1211-1279, 2012. [2] X. Chen, Y. Wang, M. Nakanishi, X. Gao, T.-P. Jung, and S. Gao. High-speed spelling with a noninvasive brain-computer interface. Proceedings of the national academy of sciences, 112(44):E6058-E6067, 2015.