Thanks for the responses. Beavis, the doors are maple and due to WAF definitely not an option to remove them from the cabinet.
Photon46, I initially detected the problem you describe of the vibration at the interface of door and cabinet and have managed to dramatically reduce this using a felt lining in the frame which makes it a tight fit. Whilst the noise is reduced significantly, I can still hear some resonance noise in the door panel itself. I think I might try your idea of dampening sheets which I can secure to the insides of the doors (so ugliness not an issue). Thanks for the suggestion.
Photon46, I initially detected the problem you describe of the vibration at the interface of door and cabinet and have managed to dramatically reduce this using a felt lining in the frame which makes it a tight fit. Whilst the noise is reduced significantly, I can still hear some resonance noise in the door panel itself. I think I might try your idea of dampening sheets which I can secure to the insides of the doors (so ugliness not an issue). Thanks for the suggestion.