In this study, the obtainment procedure and the analysis of temporal distributions of acoustic emission pulses during fracturing of structurally heterogeneous materials are considered. The possibility for pulses to be pre-separated into several groups and the pulses temporal distributions to be further analyzed independently is demonstrated. The proposed approach was evaluated on a fiberglass of STEF brand with its fracturing due to a small number of competing mechanisms – cracking of reinforcing material, delamination of fibers from the matrix, and fiber tear. Two groups of pulses were identified. A first group is a low-amplitude pulses related to spreading of microcracks, and a second group is a high-amplitude group related to spreading of macrocracks and tearing the reinforcing filaments. It is shown that during the deformation process, temporal distribution features for the identified groups are essentially different. This fact is caused by specific collective behavior features of ensembles of acoustic emission sources of different nature under deformation and fracturing of a fiberglass.