It is crucial to consider two foundational principles of phonosemantics: the principle of non-arbitrariness (motivation), principle of the arbitrariness of the linguistic sign. The former principle suggests a pervasive interrelation among real-world phenomena and objects. Numerous instances in the history of science demonstrate the discovery of connections between seemingly unrelated phenomena. In contrast, the principle of the arbitrariness of the linguistic sign asserts the independence between the signifier and the signified, clashing with the overarching principle of hierarchization. According to this principle, each element in a ’higher’ system can act as an autonomous ’lower’ system. As such, a word becomes an independent ’lower’ system, possessing a substrate—the signified and the signifier—and a structural relationship between them. Stripping a word of these connections removes its structural integrity; without structure, it ceases to be a system. Therefore, Ferdinand de Saussure, the pioneer of systemic linguistics, declared the principle of the arbitrariness of the linguistic sign, challenging the very concept of systemicity. While embracing the system of arbitrariness of the linguistic sign, we acknowledge that not all words are motivated. Many words exist whose motivation remains undetermined with current etymological research. Thus, we recognize two perspectives on this issue: natural and conventional. Fundamentally, a linguistic sign is arbitrary, yet in contemporary synchronic analysis, it manifests a dual nature: both arbitrary and motivated. It is important to discern which principle dominates in each instance of nomination. In any specific nominative act, a certain characteristic of the denoted object is selected as the basis of the nomination, and in this critical moment, the nomination is motivated rather than arbitrary. Often, the selection of this particular characteristic might be random, highlighting the nomination’s arbitrariness, or its lack of motivation. Phonetic symbolism embodies a regular, non-arbitrary connection, phonetically driven, between the phonemes of a word and the non-acoustic attribute of the denotate that forms the basis of its nomination. Phonetic semantics is a natural spontaneous connection between the phonemes of a word and the non-sound characteristic of the denonation, which serves as the basis for nomination. Scientific research aims to consider the studied phenomenon in two aspects of its manifestation: oh the one hand, phonetic semantics has a statistical character, on the other hand it is psychophysiological process based on synaesthesia, syntenemia and kinematics. Research materials are offered on the examples of Germanic and Slavic languages, which are a demonstration and confirmation of the truth of the investigation. The chronology of scientific facts about the functioning of phonetic semantics allows us to come to the conclusion that this linguistic phenomenon was developed at the early stages of the formation of languages and is in constant dynamics and processes that are regular and dynamic significantly affect the relationship between the occurrence and meaning of lexical units over time, which is evidenced by the linguistic transformations of the lexical endowment of different system languages.