Interview focuses on Sonnemann's career as an engineer in the 1950s and 1960s. During that period he contributed to large engineering and science projects such as the secret underwater acoustics array ARTEMIS and the unclassified Large Aperture Seismic Array (LASA), the largest seismic array ever built. He was a key person in the design and installation of LASA, which aimed at a better discrimination of seismic signals from earthquakes and nuclear explosions. Includes a discussion of the role of Robert A Frosch in the translation of array concept from ARTEMIS to LASA.