The acoustic behavior is an important quality criterion of technical products. Therefore, optimizing acoustic criteria is a crucial goal in the product development process. It is known that the acoustic behavior of bolted assemblies is significantly influenced by the damping in the bolted joints rather than by the material damping of the components. However, bolted joints are often dimensioned only with respect to the mechanical strength, while their acoustic behavior is often not considered during the product development process. The investigations known in literature are limited to the metal-to-metal contact so far. However, thermoplastics are also frequently used in industrial applications. It is known that the mechanical properties of thermoplastics depend on the moisture level in the components. Therefore, this article investigates the dependence of the acoustic behavior of thermoplastics on the moisture level using the academic example of the Brake-Reuß-Beam. Also, the transferability of the results to an industrial use case is demonstrated. Particular attention is paid to whether the bolted joint damping of thermoplastics also outweighs material damping as well as the influence of different moisture levels of the thermoplastic’s behavior. For the material pairing thermoplastic-thermoplastic, it was observed that the system’s vibration amplitude varies by up to 7.46 dB with different bolt preloads, yielding a significant influence of bolt damping on the system’s vibration behaviour.