The relationship between age-related changes in body physiology and certain acoustic characteristics of voice was studied in a sample of 48 men representing three chronological age grouping (25–35, 45–55 and 65–75) and two levels of physical condition (good and poor). A fundamental frequency analysis program (SEARP) was used to measure mean fundamental frequency, jitter, shimmer, and phonation range from samples of connected speech and sustained vowel production. Subjects in good physical condition produced maximum duration vowel phonation with significantly less jitter and shimmer and had larger phonation ranges than did subjects of similar chronological ages who were in poor physical condition. These differences were most apparent in the production of the elderly subjects. While chronological aging is undoubtedly a contributor to such changes in the acoustic characteristics of voice, these results suggest that age-related changes in body physiology, or physiological aging, also must be considered.

Coordination of jaw muscle activity for speech production sometimes has been modeled using nonspeech behaviors. This orientation has been especially true in representations of mandibular movement in which the synergy of jaw muscles for speech production has been suggested to be derived from the central pattern generator (CPG) for chewing. The present investigation compared the coordination of EMG activity in mandibular muscles over a range of speech and nonspeech tasks. Results of a cross-correlational analysis between EMG signals demonstrated that the muscle synergies of the mandibular system depend on task demands. Contrary to some of the models discussed, continuous speech production yielded activation patterns that were clearly not related to coordinative patterns generated by the chewing CPG.

Porcine-derived xenogeneic extracellular matrix (ECM) has been successfully used as a scaffold for tissue repair and reconstruction in numerous preclinical animal studies and human applications. These scaffolds are completely and rapidly degraded and replaced by host-derived tissues that frequently mimic the original tissue composition and architecture. The purpose of the present study was to examine the morphology of ECM scaffolds after their use for laryngeal reconstruction. Thirty adult female dogs were subjected to a partial hemilaryngectomy. The right thyroid cartilage and vocal fold were replaced with ECM scaffold, and the dogs were painlessly sacrificed from 1 week to 12 months after surgery. Histologic examination of the reconstructed tissue showed the presence of a simple squamous epithelial lining, organized glandular structures within the submucosa, reconstructed thyroid cartilage, and bundles of skeletal muscle by 3 months after surgery. We conclude that ECM scaffolds are promising templates for constructive remodeling of laryngeal tissue.

Various oral structures were evaluated in 25 normal subjects, in order to gather normative data for selected parameters of tactile perception. Results revealed a significant progression of maximal to minimal discriminatory capacity and a tendency toward increased discriminatory ability at the midline aspect of the structures.

This investigation studied the effects on articulation, duration, average peak level, and fundamental frequency of speech demonstrated by normal subjects when oral region tactile and/or auditory sensory information is altered. Thirteen female subjects read a standard passage under the following six conditions: (a) control; (b) binaural masking; (c) topical anesthetization of the oral region by application of Xylocaine HCl 4%; (d) local anesthetization of the oral region by bilateral mandibular and infra-orbital nerve block techniques employing Xylocaine HCL 2%; (e) simultaneous administration of conditions b and c; (f) simultaneous administration of conditions b and d. Recorded speech samples for all conditions were subjected to analysis by use of a high speed level recorder, a phonation timer, and an oscillographic technique. The speech samples were also analyzed for articulatory deviations by a panel of judges. Statistical analysis of the data indicated that significant alterations in average peak level, articulation, and rate variability occur under conditions of altered tactile sensation. Similar trends were also noted for the mean syllable duration and phonation/time ratio variables. In addition it was found that the effects of multiple sensory disturbances are cumulative in nature for certain speech output variables.