PROJECT SUMMARY/ABSTRACT A major aim of the parent grant is to quantify the fundamental frequency (pitch) range and vocal fold posturing stability achievable by measuring ligament properties and embedding them into a finite element fiber-gel model of vocal fold vibration. The fiber-gel model is a primary mathematical simulation component of the VoxInSilico software package. Its general application is to predict vocalization outcomes when structural and motor activation inputs are modified with surgery, therapy, or voice training. Muscle activation plots are produced that show how fundamental frequency varies with cricothyroid and thyroarytenoid activation. Laryngeal framework mechanics of translation and rotation of the cricothyroid joint and the cricoarytenoid joint are used to calculate vocal fold strain (elongation). The role of the ligament in control of fo, limitation of vertical displacement, and stabilizing adduction is quantified. The goals of the supplement project are (1) to update the code from Fortran to Python, (2) to develop user interfaces that many clinicians and voice trainers can use in daily practice, and (3) the dissemination of VoxInSilico software to a wide group of users through national voice/speech organizations.