Overview: Definitions and Meaning of Loudness.- Measurement of Loudness, Part I: Methods, Problems, and Pitfalls.- Measurement of Loudness, Part II: Context Effects.- Correlates of Loudness.- Loudness in the Laboratory, Part I: Steady State Sounds.- Loudness in the Laboratory, Part II: Time-varying Sounds.- Binaural Loudness.- Loudness in the Real World.- Models of Loudness.