Submitted by: Carl Frederickson, carlf@uca.edu on 05/15/2026
Three Physics majors presented their research at the 190th Meeting of the Acoustical Society of America in Philadelphia, Pennsylvania on Monday May 11th. The students are mentored by Dr. Carl Frederickson.
Cole Morrison presented a talk titled “Impedance measurements of 3D printed porous material.”
Abstract: Understanding the acoustic impedance of porous media is fundamental to acoustic engineering. This study investigates the relationship between acoustic impedance and key material characteristics, including porosity, pore shape, and pore length. We leveraged 3D printing technology to precisely vary these characteristics and uniformly distribute the pores across the material. Experiments were conducted using a traditional impedance tube setup with a top-mounted speaker and dual microphones, measuring frequencies from 100 Hz to 1.5 kHz. For this experiment, a custom Python script was developed that utilizes binary data acquisition and the Fourier Transform for accelerated data collection, allowing for rapid iteration without sacrificing accuracy. Furthermore, recent optimizations have led to a marked improvement in the quality of our impedance data, enabling us to compare acoustic properties with greater precision. This study can be used to influence the design of novel acoustic materials.
Bradel Lee and Armando Montoya Pina presented a talk titled “Measurement of the airflow resistance of 3D printed porous materials.”
Abstract: The concept of acoustic impedance of porous media holds significant importance in acoustical engineering. An important characteristic of porous media that influences the acoustic impedance is the media’s airflow resistance. However, due to airflow resistance measurements being highly sensitive to experiment and method design, it is a challenge to determine the airflow resistance precisely. The goal of this study is to modify a previously designed and 3-D printed airflow device that more closely follows engineering standards EN ISO 9053-1 and stabilizes the airflow through 3-D printed porous plugs being studied to reduce uncertainty of measured airflow resistance values. The studied 3-D printed porous plugs vary in multiple properties, including pore length, pore shape, pore number, and overall porosity. Using the modified airflow device and the porous plugs with varying properties, a relationship between material properties and airflow
