The morphology, histology, and tonotopic organisation of the human auditory cortex vary significantly across individuals. Similarly, auditory perception and cognition are also characterised by considerable variability in both naive and expert listeners. Focusing on both the behavioural and neural domains, this thesis explores how individual differences in auditory perception and expertise relate to the functional and structural properties of the
human auditory cortex. In the first experimental chapter, we investigate the auditory perception and cognition of two groups of auditory experts: music instrumentalists and audio engineers. We find that musicians and audio engineers have lower thresholds than controls across several psychoacoustic measures. We also see an advantage across three auditory scene analysis tasks: musicians performed best in a sustained selective attention task with two competing streams of tones and a speech-in-babble-noise task, while audio engineers could better memorise and recall auditory scenes composed of non-musical sounds. Next, we present a series of MRI investigations on the structural and functional properties
of the human auditory cortex. We introduce an automated pipeline for the classification of Heschl’s gyrus’ duplication patterns and alignment of individuals with similar morphologies. After testing the pipeline’s validity, we classify the morphology of 58
subjects and compare results with previous benchmarks and publicly available data. We then localise functional and structural homologies across gyri with different morphologies, align homologous regions, and compare the resulting average maps with those generated by existing curvature-based alignment techniques.
Finally, we explore whether the structural characteristics of Heschl’s gyrus are associated with auditory perception and musical training. We find that individuals with a single gyrus in the left hemisphere have lower pitch discrimination thresholds, and that greater myelination of the right Heschl’s gyrus is associated with lower duration discrimination thresholds. Conversely, there were no differences in musical training between individuals with different gyral morphologies.