An improved algorithm for acoustic emission source localization with P-wave velocity v(p) calculation and an enhanced methodology for P-wave onset time determination, called CLAPWaVe [1], is applied to analyze the distribution of damage within rock specimens under diametral compression. The analyses allowed the identification of four zones of damage accumulation within the specimen volume, each of them with different cracking levels, absolute energy release and associated v(p) values. The observed non-homogeneous damage distribution confirms that using a unique v(p) value for the localization of all AE sources, as usually adopted, is not representative of the real condition of the specimen. (C) 2019 Elsevier Ltd. All rights reserved.