Acoustic behavior of porous ceiling absorbers based on local and extended reaction (L)

The acoustic behavior of ceiling absorbers can be pre dicted under different surface reaction assump- tions: Local and extended reaction. This study aims to experimentally validate acoustic transfer func tions near a ceiling absorber in an anechoic chamber based on the two surface reaction models. First, a ceiling absorber with two mounting conditions is mo deled by equivalent fluid models, such as Delany- Bazley’s, Miki’s, and Komatsu’s model, in various w ays: (1) Local vs extended reaction and (2) planewave vs spherical-wave in cidence. For a single absorber under an echoic conditions, the acoustic transfer functions for four source-receiver pairs are simulated using a pressure-based image source model, and then compared with measurements. For a rigid ba cking condition, both the local and extended reaction models agree well with the measurement. For an absorber backed by an air cavity, the extended reaction model agrees better at larger incidence an gles at lower frequencies than the local reaction model.