Abstract
Problem
In-vivo phonation using animals with layered structure similarities and phonation characteristics akin to humans are needed for the study of vocal fold reparative processes. The authors’ previous studies have demonstrated the feasibility of eliciting vocalization in a flow-controlled in-vivo rabbit preparation. In the current study, the authors provide information relative to temporal stability of nerve elicited rabbit phonation.
Methods
Eight New Zealand White breeder rabbits received pulsatile current to the laryngeal nerves with airflow delivered at a constant rate. Measurements of vocal intensity and fundamental frequency were recorded every 5, 30, and 90 minutes after the onset of phonation. Pearson correlations were used to investigate relationships among vocal intensity and fundamental frequency.
Results
Phonation was elicited with fundamental frequency and intensity ranging from 300 to 1000 Hz and 68 to 80 dB SPL, respectively at 5 minutes, 55 to 840 Hz and 70 to 79 dB SPL at 30 minutes, and 51 to 438 Hz and 68 to 76 dB SPL measured at 90 minutes. Correlation coefficients revealed predictable relationships among the dependent variables over time.
Conclusion
Continuous, audible phonation within the range of human phonation was produced over a 90 minute duration using an in-vivo rabbit preparation. Expected relationships between vocal intensity and fundamental frequency were observed over time.
Significance
Considering the vocal fold microarchitectural properties and phonation characteristics of the rabbit, the in-vivo preparation described may provide a useful small animal option for investigations of phonation dependent tissue remodeling, maintenance of the vocal fold lamina propria, and development of pathology.
Support
NIH-NIDCD R03 DC008400.
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