title: Effects of changing jaw height on F1 during babble: a case study at 9 months.
abstract: An empirical gap exists in our understanding of the extent that mandibular kinematics modulate acoustic changes in natural babble productions of infants. Data were recorded from a normal developing 9-month-old infant. Mandibular position was tracked from the infant during vowel and canonical babble. Linear predictive coding analysis was used to track estimates of formant center-frequency for F1. For each sample, a correlation coefficient was computed between changes in jaw height and formant history for F1. A Mann-Whitney rank sum test reached significance for differences among coefficients for vowel and canonical babble. Coefficients for vowel babble productions were nearest to -1 with a median of r=-0.76, showing the strongest relationship between jaw position and formant history, while the median for canonical babble coefficients was r=-0.54, indicating greater contribution of the tongue and lips. This 9-month-old infant exhibited plasticity for coordinating the jaw, tongue and lips among babble types.
authors.affiliation: Division of Communication Disorders, University of Wyoming, Laramie, WY 82071, USA. rsteeve@uwyo.edu
authors.forename: Roger W
authors.initials: RW
authors.lastname: Steeve
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology*; D002663:Child Language; D006801:Humans; D007223:Infant; D007568:Jaw / Q000502:physiology*; D007804:Language Development; D008046:Lip / Q000502:physiology*; D008297:Male; D010699:Phonation / Q000502:physiology*; D010700:Phonetics; D012016:Reference Values; D013018:Sound Spectrography; D013060:Speech / Q000502:physiology*; D013061:Speech Acoustics; D014059:Tongue / Q000502:physiology*; D014741:Video Recording