https://www.nature.com/articles/nn1256.pdf (Publisher version)
Petkov, C., Kang, X., Alho, K., Bertrand, O., Yund, E., & Woods, D. (2004). Attentional modulation of human auditory cortex. Nature Neuroscience, 7(6), 658-663. doi:10.1038/nn1256.