This is a clear, comprehensive introduction to communication sciences and disorders, with an evidence-based, lifespan perspective. This edition continues the evidence-based, lifespan perspective. It reviews and explains the most recent research evidence pertaining to the assessment and treatment of communication disorders from birth through the end of life in a clear, comprehensible fashion. Each chapter is concise, yet provides comprehensive information appropriate for an introductory-level text. Students gain a basic foundation in the areas of anatomy and physiology of the speech and hearing mechanisms, and an overview of the various disorders that affect voice, fluency, articulation, language, cognition, swallowing, and hearing, along with detailed descriptions of the varying etiologies that cause these impairments