<p>Human subject experiment data.</p>

The sounds often co-occur, arriving at the ear of a human listeners as a mixture of the different sources. The auditory system is tasked with segregating the individual sound sources of the mixture into meaningful representations.

In contrast with human auditory perception in urban environments, which include speech and music, little is known about our capacity to segregate mixtures common in natural environments. Here, we report on the capacities of the human auditory system when presented with mixtures of bird vocalizations – that is, scenes common in natural environments – by systematically varying the number of vocalizations from the same species and from different species.