1 Introduction: On the Treatment of Hearing Loss 2 Fundamentals of Hearing Aid Acoustics and Hardware 3 Standards for Assessing Hearing Aid Performance 4 Hearing Aid Coupling: Theory and Application 5 Hearing Aid Coupling: Techniques and Technology 6 Audio Signal Processing for Hearing Aids 7 Fundamentals of Real-Ear Measurement 8 Real-Ear Measurement Techniques 9 Hearing Aid Prescriptive Fitting Methods 10 Outcome Measures in the Prescription of Hearing Aids for Adults 11 Hearing Aid Selection and Prescription for Children 12 Cochlear Implants in Adults 13 Cochlear Implants in Children 14 Bone Conduction Hearing Solutions 15 Hearing Assistive and Related Technology 16 Hearing Protection Devices 17 Tinnitus and Sound Sensitivity