Vocal fold injury alters acoustic phenotype despite preserved vocal activity

Vocal communication depends on the biomechanical integrity of the vocal folds, yet how impairment alters vocal behavior remains poorly understood. We used the California mouse (Peromyscus californicus), a highly vocal species that produces songs through airflow-induced vocal fold vibration, to experimentally examine how defined vocal fold injury alters vocal production. Longitudinal recordings were combined with histological assessment to track changes in vocal function after impairment. Injury produced acute edema of the lamina propria and thyroarytenoid muscle. Despite stable levels of vocal activity, the vocal phenotype shifted characteristically following injury. Thus, vocal behavior can persist despite substantial alteration of the biomechanical tissues underlying sound production, demonstrating that maintenance of behavioral output does not necessarily indicate preservation of the physiological system that generates it. More broadly, these findings establish an experimental link between vocal fold injury and vocal phenotype and provide a framework for understanding how tissue damage and remodeling can reshape acoustic communication even when vocal behavior is maintained. Because repeated vocalization can impose substantial mechanical demands on vocal folds, this framework may have broad relevance for understanding how vocal use, injury, and tissue remodeling interact to shape vocal communication.