When I use a Madrona Labs plugin (Aalto, Kaivo, Sumu), I hear a wave sound that resembles ocean waves at regular intervals (60 seconds). It doesn't matter if I'm playing the instrument(s) or not. It happens with each plugin on each of the DAWs mentioned above. It also happens on different presets.
Are your plugins registered? If not, that's why you hear the ocean sound. The demo versions play the sound until you register them.
Now that I think about it I should add a popup message when the demo sounds plays also, to make this clearer.
Thanks for writing.