In sensory systems, the thalamus has historically been considered a relay station. Neural representations of temporal modulations in the auditory system undergo considerable changes as they pass from the inferior colliculus (IC) to the auditory cortex. We sought to determine in awake primates the extent to which auditory thalamic neurons contribute to these transformations. We tested the temporal processing capabilities of MGB neurons in awake marmoset monkeys using repetitive click stimuli. MGB neurons were able to synchronize to periodic clicks at repetition rates significantly higher than auditory cortex neurons. Unlike responses in the MGB of anesthetized animals, more than 40% of MGB neurons in awake marmosets displayed non-synchronized discharges when stimulated by high click rates (short interclick intervals). Such non-synchronized MGB responses typically occurred at higher repetition rates than those observed in auditory cortex. In contrast to auditory cortex neurons, many MGB neurons exhibited both synchronized and non-synchronized discharge patterns. In both MGB and auditory cortex, synchronized and non-synchronized responses represented complementary ranges of interclick intervals (1/click rate). Furthermore, the temporal processing abilities of some MGB neurons were sensitive to the spectrotemporal parameters of the click stimuli used. Together, these findings suggest that MGB neurons participate in active transformations of the neural representations of temporal modulations from IC to auditory cortex. In particular, the MGB appears to be the first station in the auditory ascending pathway in which substantial non-synchronized responses emerge.