This special theme issue of Schizophrenia Bulletin presents a series of related articles focusing on auditory hallucinations, prepared by members of the International Consortium on Hallucination Research [InCoHR] working groups. The InCoHR is a large collaborative framework that serves as a platform for researchers to meet and collaborate on multidisciplinary projects relating to auditory hallucinations [AH] and discuss methodological issues facing transdiagnostic research. Laroi et al. observe the similarities in characteristic features of AHs in different clinical and nonclinical groups, but they also note that differences exist, reflecting the contribution of disease-related process. Waters et al. use findings of shared cognitive impairments across different diagnostic groups with AHs to propose a novel theoretical cognitive framework. Allen et al. describe that the neurobiological substrates of AHs include neural systems involved in language processing, as well as sensory and nonsensory brain regions and that studies are increasingly using fine-grain analysis of patients' characteristics in analyzing neuroimaging data. Ford et al. discuss different neurophysiological approaches and describes hallucination-related alterations in activity in temporal and frontal regions of the brain and particularly in auditory cortical areas. Finally, Sommer et al. review different treatment options for AHs in schizophrenia and other disorders, including pharmacological treatment, cognitive-behavioral therapy [CBT] and acceptance and commitment therapy [ACT], transcranial magnetic stimulation [TMS], and electroconvulsive therapy [ECT]. These related publications describe the current substance and direction of research on AHs across different diagnostic groups.