Design and construction of a convertible hemi/anechoic acoustical laboratory for testing space flight hardware at the NASA Glenn Research Center

Abstract

At the NASA Glenn Research Center, science experiment payloads developed for the International Space Station are designed to meet noise emission criteria that promote hearing conservation and speech intelligibility goals. A key component in the successful design of low-noise hardware is the frequent use of acoustical testing as a diagnostic and design verification tool. NASA has designed and constructed a convertible hemi/anechoic acoustical testing laboratory that provides convenient access to accurate and repeatable sound pressure level measurements as well as state-of-the art capabilities for sound power level testing per ANSI S12.35 using a multichannel PC-based data acquisition system. The laboratory consists of a 100-Hz hemianechoic chamber, vibration-isolated to 3 Hz, with 21′×17′×17′(h) interior working dimensions and removable floor wedges. A separate, sound-isolated control room doubles as a test support equipment enclosure when testing flight hardware that requires remote connections to high-noise support equipment and utilities. Movable modular furnishings facilitate reconfiguration of the enclosure, and data acquisition and test control functions are easily relocated to an adjacent quiet area. The Glenn Research Center Acoustical Testing Laboratory also offers a full range of noise control services to assist payload developers with meeting the ISS noise emission criteria.

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