Noise and sound can cause confusion for someone with Dementia. Many of the sounds we take for granted can disturb people in the later stage of Dementia simply because they no longer recognize that sound. This might be a ringing telephone, vacuum, doors closing, etc.
Pay attention to the volume of music. Do you have a TV and music on that same time? That is too much noise and is overstimulating.
Recognize the noise and make changes so the environment is calming for the person. Remember. less noise is better.