1. Overview of Acoustic Logging - Applications and Recent Advances. 2. Elastic Wave Propagation in Boreholes. 3. Elastic Wave Velocity and Attenuation Estimation from Array Acoustic Waveform Data. 4. Permeability Estimation - Theory, Methods, and Field Examples. 5. Acoustic Logging in Anisotropic Formations: Theory, Method, and Applications. 6. Summary, Related Topics, and Road Ahead.