Cognitive semiotics explores the notion of polysemiotic communication, understood as the intertwined use of two or more semiotic systems and semiotic resources. In real communicative situations, spoken language is a component of a more complex polysemiotic system in which speech is coupled with several other meaningful bodily activities, including body posture, head movements, facial expressions, gaze, and manual gestures. Addressing polysemiotic communication, this paper focuses on the co-expression of speech and gestures. The latter is understood as the so-called spontaneous gesticulation, i.e., gestures that are spontaneously produced, global-synthetic, holistic, and not explicitly planned or monitored. This paper argues that an account of the integration of spoken language and embodied activities can be found in phenomenology, especially within Merleau-Ponty’s philosophy of embodiment. The co-expression of speech and gestures is presented as the co-emergence of two aspects of the same phenomenon: immersion of an embodied subject in an intersubjective and meaningful world. In this context, subjects experience various forms of expression (gesturing, speech) as the activity of one sensing-and-acting body. Finally, the paper considers the dynamicity of pre-reflective and reflective consciousness as one of the key factors contributing to the dynamic relationship between speech and gesturing.