Measurements of Acoustic Absorption of Baffles Comparing Edge Effect and Room Position

Abstract

This study presents an experimental analysis of the acoustic absorption performance of suspended baffles, focusing on the influence of edge effect, and room position. Measurements were conducted in a 223 m(3) reverberation chamber according to ISO 354. The experimental setup included 120 x 20 cm baffles (spaced at every 30 cm) composed of high-density glass wool and thermally treated polyester felt. Key variables included three room positions (single wall, double wall and middle of the room), and three mounting configurations of edge cover (deep well, well and no-well) to assess performance variations. The methodology involved sound absorption measurements using pink noise excitation, eight omnidirectional microphones, and dodecahedron loudspeakers. The results revealed that the deep-well method minimized edge effects, leading to consistent absorption results across different room positions. In contrast, well and no-well configurations exhibited significant variations. Measurements at the room center consistently demonstrated higher absorption due to additional reflections, while configurations adjacent to two walls exhibited the lowest performance. Findings emphasize the importance of edge effect and mounting configurations in the measurement of acoustic efficiency. This study contributes to the understanding of baffle-based sound absorption in interior spaces.