Moreover, in this study it was demonstrated that communicative vocalizations were shorter compared to 'investigative ' vocalizations (approximately 0.35 vs. 1 second).
Consonants are grouped into three major categories for ease of comparison with infants' vocalizations : labials, alveolars and velars.
Quasivowels, representing the least advanced category theoretically, are the first vocalizations with speech-like quality to be produced in very early infancy.
Laboratory assistants kept a rough count of vocalizations during sessions.
Studies of cetaceans have uncovered a number of patterns of behaviour and vocalizations, which some cetologists have ascribed to cultural processes.
One is an unstable volatile substance that elicits ultrasound vocalizations in male mice as an unconditioned response.
Other mammals have only rigid, species-specific, limbic vocalizations.
No single consonant or vowel segments, vegetative sounds, or vocalizations not determined to be canonical babbling were analyzed.
