Analyzing Speech Quality Perception Using Electroencephalography

Common speech quality evaluation methods rely on self-reported opinions after perceiving test stimuli. Whereas these methods-when carefully applied-provide valid and reliable quality indices, they provide little insight into the processes underlying perception and judgment. In this paper, we analyze the performance of electroencephalography (EEG) for indicating different types of degradations in speech stimuli. We show that a certain EEG technique, event-related-potentials (ERP) analysis, is a useful and valid tool in quality research. Three experiments are reported which show that quality degradations can be monitored in conscious and presumably non-conscious stages of processing. Potential and limitations of the approach are discussed and lines of future research are drawn.