“…The endocrine activity in males is responsible for voice break in puberty [2,8,[12][13][14], while in women, the timbre and pitch of voice may undergo cyclic changes in relation with the menstrual cycle [1,2,7,12]. It should be noted, however, that the anatomy of the larynx and the timbre of voice are the secondary sex characteristics, as well as the structural proportions, increased muscle mass, the skeletal structure and the growth of body hair [1,7,8,15]. Nevertheless, one should take into consideration the fact that the vocal efficiency of the larynx is influenced by many factors, such as rest or body hydration [7], and voice, as an individual feature, depends on a number of individual properties of man: personality, emotional state, diseases and mental disturbances (depression, anhedonia, anxiety) [7,8,16].…”