Reflexive (vegetative) vocalizations

Non-speech sounds such as cries, grunts, sneezing and hiccoughs during the first two months after birth.  One characteristic of these vocalizations is referred to as quasi-resonant nucleic (faint, low-pitched grunt-like sounds with muffled resonance, with a lack of energy above 2000Hz).  These sounds give way those that indicate an increase in the control of phonation (e.g., cooing, babbling).  

See Babbling, Cooing, Crying, Fussing