Fig. 1.

The regression procedure with the used predictors for the whole time series. The first and third predictor (right panel) were associated with voice onset and offset and were created by convolving an impulse function (left panel) at voice onsets and voice offsets respectively, with a subject specific Gaussian function over the whole time series. The second predictor, which was related to sustained activity during vowel pronunciation, was created by convolving a block function (left) between voice onset and voice offset with the same Gaussian function. Horizontal bars at the top (speech signal) indicate the time periods where subjects spoke. A regression was performed and the signal (gray) and model thereof (black) are shown at the bottom.