The noise is caused by the presence of food-grade silica gel desiccants inside the packaging, which are included to protect the device from moisture during transport. When the box is moved or shaken, the desiccant pellets can create a rustling sound as they shift within their packaging.
This is a normal occurrence and does not affect the quality or functionality of your device. The desiccants are essential for maintaining the device's condition during shipping, and the sound you hear is simply due to their movement inside the box.