Acoustical study of the development of stop consonants in children

This study focuses on the acoustic patterns of stop consonants and adjacent vowels as they develop in young children (ages 2;6-3;3) over a six month period. Speech is generated using a series of articulatory, laryngeal, and respiratory gestures that children must learn to reproduce. As a child's speech develops, the gestures become more precise and coordinated, and the resulting acoustic patterns are refined. To explore their development, over forty different acoustic measurements were made on each of 1049 recorded utterances from ten children, including durational, amplitude, spectral, formant, and harmonic measurements. These acoustic data are interpreted in terms of the supraglottal, laryngeal, and respiratory actions that give rise to them. Data show that some details of the child's gestures are still far from achieving the adult pattern. Children have acquired appropriate positioning of their primary articulator for producing a stop consonant, but are still learning to adjust the tongue body during the consonant production. At constriction release, children have a high incidence of multiple bursts and a short burst duration, interpreted as a reflection of increased articulator compliance, smaller articulator size, and high subglottal pressure. Children are also still acquiring correct adjustment of vocal fold stiffness and glottal spreading as well as intraoral pressure, as evidenced by long voice onset times and highly variable fundamental frequencies. Additionally, amplitude changes over the course of the utterance and high amplitude variability reveal that children have not yet gained full control over subglottal pressure.

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Imbrie, Annika Karin Karlsson

Advisor dc:contributor.advisor

• Kenneth Noble Stevens.

• Harvard University--MIT Division of Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/33072
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/33072

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33072