Patil et al. (2012) - The Biological Bases of Musical Timbre Perception (article, .pdf available) User thisicouldnotdo, in the The Perception and Cognition of Music subreddit, 06 Nov 2012
Neurophysiological study explains how our brain distinguishes sounds of different musical instruments User raja_2000, in the Reddit Science subreddit, 02 Nov 2012