The paper presents the results of an analysis of the acoustic emission signals recorded both by piezoelectric and adaptive fiber-optical sensors. Fiber-optical sensors have been embedded into the polymer composite material during their manufacture. Fiber-optical sensors are designed on the base of adaptive interferometer that uses a dynamic hologram formed in the photorefractive crystal. It has been shown that the sensitivity of adaptive interferometer allows the detection of acoustic emission signals generated by the Hsu-Nielsen source. Peculiarities of material sound velocity determination with use of acoustic signals detected by distributed fiber-optical sensors are discussed.