As all of Alexandra’s senses are fully simulated and injected by Lumina through the brain implant, Alexandra has no need for her biological sense of hearing or balance.
Alexandra’s eardrums and inner ear are surgically removed, making it physically impossible for her to hear anything, except through the signals from the brain implant. Her inner ear is replaced with sensors that give her the same, even more detailed, information, but fully under the control of Lumina. This allows for even Alexandra’s sense of balance and spatial awareness to be controlled completely by Lumina.
Finally, the space within her ear and ear-canal is then filled with an advanced biocompatible polymer that solidifies into a rigid structure, creating a permanent seal. This material blocks any natural auditory sensation and even integrates with the tissue surrounding the ear, resulting in the entire area growing closed, as if Alexandra never even had ears.
Finally, Alexandra’s entire outer ears are removed, leaving behind only smooth skin, as if Alexandra’s human body never had ears to begin with.