Challenges in understanding and modeling speech perception

Speech perception performance is one of the most widely used measures in audiology and auditory research. Nevertheless, our understanding of how speech is processed by the auditory system is limited. This is not only due to the subject—the complexity of the speech signal itself and the intricacy of disentangling target speech from interfering sounds—but also to the way it is approached: different aspects of speech perception are studied by largely separate research communities. Also when only early processing of speech is considered, excluding psycholinguistic aspects and effects of memory and learning, at least three relevant research fields can be discriminated: audibility and masking, auditory scene analysis, and attention. Although there is increasing interest in the crosslinks between these fields, approaches are still insufficiently integrated and important questions remain unanswered. Furthermore, modeling efforts are lagging behind and are only partly driven by advances in neurophysiological research. After reviewing progress in the three fields, a conceptual model will be presented that attempts to tie results together. Finally, knowledge gaps and open research issues will be highlighted.