The article is devoted to the problem of voice signals recognition means introduction in the system of distance learning. The results of the conducted research determine the prospects of neural network means of phoneme recognition. It is also shown that the main difficulties of creation of the neural network model, intended for recognition of phonemes in the system of distance learning, are connected with the uncertain duration of a phoneme-like element. Due to this reason for recognition of phonemes, it is impossible to use the most effective type of neural network model on the basis of a multilayered perceptron, at which the number of input parameters is a fixed value. To mitigate this shortcoming, the procedure, allowing to transform the non-stationary digitized voice signal to the fixed quantity of mel-cepstral coefficients, which are the basis for calculation of input parameters of the neural network model, is developed. In contrast to the known ones, the possibility of linear scaling of phoneme-like elements is available in the procedure. The number of computer experiments confirmed expediency of the fact that the use of the offered coding procedure of input parameters provides the acceptable accuracy of neural network recognition of phonemes under near-natural conditions of the distance learning system. Moreover, the prospects of further research in the field of development of neural network means of phoneme recognition of a voice signal in the system of distance learning is connected with an increase in admissible noise level. Besides, the adaptation of the offered procedure to various natural languages, as well as to other applied tasks, for instance, a problem of biometric authentication in the banking sector, is also of great interest.

A significant threat to critical infrastructure of computer systems has a destructive impact caused by infrasound waves. It is shown that the known infrasound generations are based on using the following devices: a Helmholtz Resonator, Generation by using a Pulsating Sphere such as Monopolies, Rotor-type Radiator, Resonating Cylinder, VLF Speaker, Method of Paired Ultrasound Radiator, and airscrew. Research of these devices was made in this paper by revealing their characteristics, main advantages and disadvantages. A directional pattern of infrasound radiation and a graph of dependence of infrasound radiation from the consumed power was constructed. Also, during the analysis of these devices, there was proven a set of basic parameters, the values of which make it possible to characterize their structural and operational characteristics. Then approximate values of the proposed parameters of each those considered devices, were calculated. A new method was developed for evaluating the effectiveness of infrasound generation devices based on the definition of the integral efficiency index, which is calculated using the designed parameters. An example of practical application of the derived method, was shown. The use of the method makes it possible, taking into account the conditions and requirements of the infrasound generation devices construction, to choose from them the most efficient one.