Cove's vibrations are very subtle. To find a test the intensity, try this:
Start a session before you put on Cove
Set the intensity to level 5, and feel the pads with your fingers to get an idea of the feeling
Put on Cove, and let the session run at intensity 5 for a few minutes so you can acclimate
Adjust the intensity if needed, bearing in mind higher intensity is not more effective