The paper deals with the problem of voice identification of the pilot as part of the crew, which is one of the ways to improve the interface of the cockpit of a modern aircraft. The main trends of pilot voice identification in the task of improving the cockpit interface are voice control of onboard equipment and accident investigation. We introduce a method for identifying the speakers personality using the speakers voice transfer function by frequency and the k-nearest neighbors data classification algorithm. Due to the nature of the task, identification was carried out for small groups of operators of up to four people. The main results of testing the proposed method on the experimental speech data that include 3 and 20 different isolated words are given. Findings of research show that the operator can be identified by a small number of code words with an accuracy of about 97--99 % when using the speakers voice transfer function by frequency. The paper also presents a comparison of the results of applying the methodology for pilots of helicopter aviation with the diagnosis of hearing loss and for a group of operators without diseases of the organs of hearing.