Phonation is the act or process of producing speech sounds; To utter or vocalize sound/sounds using one's voice.

Laryngeal muscles that function in phonation.

Phonation stage is the first sound production stage in babies between 0 and 2 months. It involves quazi-resonant or quazi-vocal sounds, the child will later develop into the primitive articulation stage (1-4 months) with the appearance of primitive syllables.

Using signlanguage to comminicate with an infant.

Articulation refers to the physical movements of the speech organs to produce speech sounds, phonation is the vibration of the vocal cords to produce sound, and speech is the overall expression of sounds, including articulation and phonation, to convey language.