Time series and spectrograms of the stimuli of 180 ms duration. A: The spectrogram of the ‘ba’ sound, limited at 2000 Hz, reveals the first formant at 700 Hz, the second at 1200 Hz, and the fundamental frequency of 120 Hz at t = 0 falling to 100 Hz at the end. Time zero is adjusted to the onset of the ‘ba’ stimulus. B: The ‘mba’ sound differed from the ‘ba’ sound by 10 ms of additional pre-voicing. The arrows indicate the voice onset. The pre-voicing intervals of 10 ms for ‘ba’ and 20 ms for ‘mba’ are marked with red bars below the time series. C: Time series and spectrogram of the frozen noise stimulus.
Ross et al. BMC Neuroscience 2013 14:151 doi:10.1186/1471-2202-14-151