Noise‐Reduction Study in a Scaled‐Model Acoustic Test Facility Free

The acoustic properties of five insulation materials were investigated in a $110‐scale$ model acoustic facility. The materials were designed for applications in space vehicles. The model facility, consisting of a reverberation chamber coupled to an anechoic chamber, was evaluated for its use in noise‐reduction testing. It was found that a reasonably diffuse sound field existed above 900 Hz. Modal‐density graphs of the reverberation chamber and spatial acoustic gradients measured within the chamber and across the test‐panel opening are compared to an idealized facility. [This work was performed for the National Aeronautics and Space Administration under contract.]