This book interconnects two essential disciplines to study the perception of speech: Neuroscience and Quality of Experience, which to date have rarely been used together for the purposes of research on speech quality perception. In five key experiments, the book demonstrates the application of standard clinical methods in neurophysiology on the one hand, and of methods used in fields of research concerned with speech quality perception on the other. Using this combination, the book shows that speech stimuli with different lengths and different quality impairments are accompanied by physiological reactions related to quality variations, e.g., a positive peak in an event-related potential. Furthermore, it demonstrates that – in most cases – quality impairment intensity has an impact on the intensity of physiological reactions.