Impacts of growing time and physical modifications on the acoustical properties of mycelium-composite materials

The need to control how sound travels within a room, or how sound is transmitted from one room to another room, has necessitated a commercial industry that manufactures sound absorbing panels and sound transmission reduction products. The design of acoustic treatments targets high acoustic absorption or high transmission loss, respectively. However, many of the present-day treatments available include materials that do not meet current sustainability demands (i.e., petrochemical foam, hard Styrofoam, and molded plastic). This paper investigates sustainable options for acoustic products and seeks to quantify the acoustic absorption and transmission loss of “myco-materials,” a composite of lignocellulosic fibers bound together by fungal mycelium. These myco-materials were tested in an impedance tube under various conditions, including several modifications to the myco-material specimens that sought to alter the acoustic properties. The impedance tube tests show that myco-materials show moderate acoustic absorption and transmission loss. Myco-materials have potential for future research into improving both absorptive and transmission loss properties, they are relevant for diffuse surfaces in architectural acoustic applications.