BACKGROUND 0002 There are various needs for understanding the shape and size of
cavity Surfaces, such as body cavities. For example, hearing aids, hearing protection,
custom head phones, and wearable computing devices may require impressions of a
patient's ear canal. To construct an impres sion of an ear canal, audiologists may inject a
silicone mate rial into a patient's ear canal, wait for the material to harden, and then provide
the mold to manufacturers who use the resulting silicone impression to create a custom …