After several decades of research, wave energy has reached a pre‐commercial stage, emerging as a potential industry for the future. Despite the wave energy being considered as an environmentally friendly activity, it will probably have positive and negative aspects. The marine environment is an important area of biological diversity, hence the concern about the possible effects of underwater noise has increased among developers and promoters. While it is not expected that each individual device will produce a high level of noise, the deployment of several devices in the same farm, operating day and night, may have an effect on the fauna. However, the acoustic characterization of wave energy devices (WEDs) is not trivial; the noise generated and propagation will depend on oceanographic characteristics and operational conditions. The acoustic signature of each WED is expected to be produced from a variety of different components (mechanical or other moving parts) related to the device itself or by its interaction with the environment. Just after the characterization of the noise emitted by the WEDs and potential coincidence with the hearing sensitivity range of marine animals, a first assessment of possible impacts on the animals can be attempted.