My mom has last stage dementia. The doctors say the last thing that will happen to her is she will lose her voice?

Not necessarily. My husband and my mother, both with dementia, never lost their voices, though my husband's got more quiet in the moderate stage.

Swallowing problems may get severe near the end. Eating may cease. Pneumonia often happens near the end and is the immediate cause of death. (This may be from aspirating food or liquid into the lungs.)

Each case is different.

Have you requested Hospice care? They can help you understand what is happening as the end of life nears, as well as help keep your loved one comfortable.