Acoustic testing methods play a very important role in the quality assurance of technical components and semi-finished products. Essentially, these are the classic contact ultrasound with frequencies of several MHz. With the increasing use of lightweight materials and components, conventional non-destructive testing methods are reaching their limits. The lecture gives examples of how the quality of the test results can be improved by means of novel test approaches for complex components such as composite materials and sandwhich components. As a first example, the lecture highlights the method of local defect resonance in first technical applications where direct imaging detection methods in the form of IR-camera or acoustic camera are also used. Furthermore, it will be shown how the use of broadband laser excitation and broadband detection opens up new ways in pore detection in CFRP components. Lightweight construction often requires the combination of different materials, which then often have to be bonded adhesively. We report here on the use of nonlinear ultrasound to detect insufficiently bonded components. Since automation and the use of robotics will become increasingly important, we also highlight the use of air-coupled ultrasound on a new type of dual robot system, which can be positioned via air cushions and referenced by means of a special laser system.