ESA Science & Technology - The CHEOPS satellite surrounded by microphones used for acoustic noise testing

During acoustic noise testing, the sound pressure above, below and around CHEOPS was monitored by microphones mounted on booms. The powerful noise horns on the far wall may look like standard hifi speakers, but have a different design and are powerful enough to reproduce the noise generated by rocket engines. The walls of the test chamber are made from thick concrete and coated with epoxy resin to reduce sound absorption and increase reflections to create a reverberant sound field.