Stimuli were presented in blocks of constant or random tone sequences. All of those tone sequences were either presented in silence or in noise. The length of the tone stimuli was 0.7 s, the ISI was randomized between 1.3 and 2.3 s. Exemplary sound files are attached to Additional file 1.
Lagemann et al. BMC Neuroscience 2010 11:156 doi:10.1186/1471-2202-11-156