Enhancing Acoustics Education Through Experiential Learning: Implementation of an Impedance Tube for Teaching Sound Absorption in Materials
Academic Article in Scopus
This paper presents the design, construction, and educational implementation of a low-cost impedance tube for teaching sound absorption in an undergraduate Acoustics course. The tube, built from carbon steel and integrated with MATLABbased analysis, follows ASTM E1050 and ISO 10534-2 standards for normal-incidence absorption measurements. Technical validation showed absorption curves consistent with literature and manufacturer data, with uncertainties below 1% in amplitude and 0.6° in phase. Tests with foams, carpets, and fibrous panels confirmed accuracy and repeatability, demonstrating suitability for instructional use. Educational evaluation involved 52 students divided into control and experimental groups. The experimental group, which conducted hands-on measurements, achieved higher learning gains (normalized gain 0.56 vs. 0.27), reported greater motivation (90% vs. 55%), and demonstrated stronger analytical skills in laboratory reports. The results indicate that the impedance tube functions not only as a reliable measurement device but also as a pedagogical tool that improves conceptual understanding, engagement, and skill development. This approach offers a scalable pathway to strengthen acoustics education in contexts with limited access to specialized laboratories.
