A Novel Model for Examining Recovery of Phonation After Vocal Nerve Damage

Objectives/Hypothesis Recurrent laryngeal nerve injury remains a dominant clinical issue in laryngology. To date, no animal model of laryngeal reinnervation has offered an outcome measure that can reflect the degree of recovery based on vocal function. We present an avian model system for studying recovery of learned vocalizations after nerve injury. Study Design Prospective animal study. Methods Digital recordings of bird song were made from 11 adult male zebra finches; nine birds underwent bilateral crushing of the nerve supplying the vocal organ, and two birds underwent sham surgery. Songs from all the birds were then recorded regularly and analyzed based on temporal and spectral characteristics using computer software. Indices were calculated to indicate the degree of similarity between preoperative and postoperative song. Results Nerve crush caused audible differences in song quality and significant drops (Pآ آ 0.05) differences in song after nerve crush. Conclusion The songbird model system allows functional analysis of learned vocalization after surgical damage to vocal nerves.