1. A method for determining a form for a headphone part, the method comprising: receiving data representing at least one ear model; using a data processing device, orienting the at least one ear model within a coordinate system using the data, wherein orienting the at least one ear model is based at least in part on alignment with respect to at least one area of an ear; using the data processing device, determining a representative model from a plurality of oriented ear models including the at least one oriented ear model, the representative model representing a volume of space common to at least two of the oriented ear models; determining at least one of a size and shape of the headphone part based on the representative model; receiving comfort level data for the at least one ear model, wherein the comfort level data is obtainable from prototype testing and indicates a level of comfort associated with at least one location on a surface of an ear; rendering a visualization for the representative model within a computer aided design application; and overlaying the visualization with visual indicators based on the comfort level data for the oriented ear models.