A series of systematic impact tests have been carried out to investigate the influence of particle size, free stream velocity, particle impact angle, and nominal particle concentration on the amount of energy dissipated in a carbon steel target using a slurry impingement erosion test rig, as indicated by the acoustic emission (AE) recorded by a sensor mounted on the back of the target. Silica sand particles of mean particle size 152.5, 231, and 362.5 μm were used for impingement on the target at angles varying between 30° and 90° while the free stream velocity was changed between 4.2 and 12.7 m/s.