DescriptionThe caudomedial nidopallium (NCM) is an area of songbird telencephalon analogous to a portion of the mammalian auditory cortex and is important for conspecific song discrimination, memorization and individual recognition. The tuning properties of NCM neurons differ between canaries and zebra finches. To test whether these differences reflect recent experience, three groups canaries of each sex were housed for 9 days in different conditions: conspecific aviary (normal condition), zebra finch aviary (cross condition) or in isolation box (isolation condition). Extracellular multi-unit electrophysiological responses to simple pure tone stimuli (250-5000Hz) in NCM of awake birds were recorded. Both phasic and tonic responses were measured, and auditory tuning width was quantified as the number of contiguous frequencies at least 1 SD above baseline. Compared to normal birds, tuning was narrower in cross-housed birds and wider in isolated birds. This effect was more pronounced in female canaries than in males. Tuning width was narrower early in the year and broader later in the year and this effect was most pronounced in cross-housed males. These findings demonstrate that tuning properties of NCM neurons are not fixed, but change in response to recent experience. The acoustic and social environment and season-related hormonal change may have important effects on auditory tuning and thus affect the perception of complex songs.