Towards User-Friendly Spelling with an Auditory Brain-Computer Interface: The CharStreamer Paradigm
Each group of letters is presented from a different direction. Spectrograms of six selected auditory stimuli are shown in B. The course of a trial is shown in C, depicting a sequence of several consecutive iterations. Part D visualizes excerpts with ∼2 seconds duration. To illustrate the mapping of the three groups to the stereo headphone tracks, the corresponding waveforms for each condition are displayed in the background. Moreover, a magnification of plot C is provided in the top-left corner of D.