Exploring NASA's Sound-Killing Aero-Acoustic Propulsion Lab
NASA's Aero-Acoustic Propulsion Lab (AAPL) in Cleveland, Ohio, is an anechoic chamber that absorbs sound and prevents echoes. The lab is covered with 17,000 spiky fiberglass wedges that absorb sound and provide highly accurate sound level readings for aircraft and rockets. Researchers test jet and rocket engines inside AAPL to develop quieter aircraft. The fiberglass wedges are an excellent sound absorber and come in wedges because that's the shape that absorbs the most sound with the least material. AAPL helps make the world a quieter place by ensuring new aircraft parts meet noise guidelines.