Initial assessment of MR's auditory cognition revealed impaired recognition of sounds in the musical and environmental auditory domains. MR was unable to recognise or discriminate between melodic or environmental sounds due to an inability to match the incoming percept with a pre-existing or newly acquired representation. In and of themselves, these overall results neither implicate nor preclude the possibility of an underlying perceptual deficit. However, MR's specific impairment for identifying identical melodies, coupled with the presence of a mild form of musical illusion on the environmental sound identification task, indicate a likely perceptual deficit. MR's perceptual function at the levels of pitch perception and auditory scene analysis were interrogated in order to confirm the existence and pervasiveness of a low-level perceptual deficit.