The study investigated auditory object cognition in patients with dementia syndromes like Alzheimer's disease and primary progressive aphasias. An experimental battery assessed three levels of auditory processing - early perceptual coding, perceptual representations of whole objects, and recognition of object semantics. Results showed distinctive profiles of impaired auditory object processing in different dementia syndromes after controlling for non-verbal working memory performance. The findings suggest dementia syndromes affect auditory object cognition through separable stages of analysis. Future research should study larger cohorts and additional diseases to better understand auditory dysfunction in these disorders.