I have been DE shaving with a Blue Tip Super Speed for awhile and have been getting great shaves. Maybe I'm nuts but it seems that the sound the blade makes as it cuts the hair changes with each blade brand. Astra's sound different than Sharks, Feathers sound different than Derby. Am I crazy or does each blade have it's own sound and could this be due to the coating ? Sharpness ? or maybe the thickness of the blade? Has anyone else noticed this or do I need to seek professional help and check into a rubber padded room?