It’s been almost three years since Rolls-Royce revealed the second-generation Ghost luxury sedan which was touted as one of the quietest combustion engine cars. The British marque went to great lengths to eliminate outside noise and make the cabin of the new Ghost a relaxing and quiet space. This included things like adding 220lb of sound-deadening materials at various parts of the car. Even the double-glazed windows were fitted with a clear composite center sheet while the luxury sedan’s tires were lined with lightweight acoustic insulation foam.
Interestingly, the early prototypes of the luxury sedan were so silent on the inside that they caused discomfort to the occupants. The engineers realized that the near-total silence inside the cabin was disorienting as the lack of sound didn’t match up with the car’s movement.
Rolls-Royce chief engineer Jon Simms told Bloomberg that during the early phase of Ghost’s five-year development period, the cabin was so silent it felt unnatural and caused the test drivers to become disoriented, “bordering on nausea.” In fact, the only way to fix it was to make the cabin louder; however, the process was a lot more complicated than it sounds. The sound engineers had to work hard to harmonize various sounds inside the cabin in a way that they all add up to create a continuous soft and soothing whisper. For example, the rear seat frames and other trunk components were designed to vibrate at a specific low frequency. Furthermore, the massive 6.75-liter twin-turbo V12 was specifically calibrated to produce a pleasing sound.