My husband constantly gets up to explore every little noise he hears in the house or outside. Is there something I can do to manage?

Try playing music. It will be soothing, relaxing and take his mind away from distractions.

Gincat: Perhaps he can go to day care.

I agree with the other suggestions. Also wanted to add — Perhaps 2-3 days per week in adult daycare would help. At least it would get him out of the house and you some peace and quiet. Maybe if you are lucky, it would also give him something else to focus on, tire him out a little, and maybe give his schedule more structure.

When my dad had dementia, he had a lot of house and property related obsessions that drove my mom around the bend, plus some of them were dangerous and destructive. In his case, he was also doing this mischief in the middle of the night (climbing up onto the roof, disconnecting water pipes to house, prying the thermostat off the wall, unplugging the computer and TV then waking her up to say they didn’t work, etc) making it even worse. Getting him on Seroquel plus trazodone (after several trials of various meds to find out what worked for him) improved his sleep and reduced the overall obsessions considerably. My mom never agreed to adult daycare no matter how crazy he drove her.

Good luck!

You could try a white noise machine.

Have you tried keeping the blinds or curtains closed so he can't see outside? That's one thought.
And how about perhaps leaving the TV or radio up loud enough where he can't possible hear every noise in the house or outside? Just another thought.
And my final thought would be to speak to his doctor about putting your husband on some kind of medication to help with his agitation.

Not really. Hypervigilance is the norm. You could discuss this with the doctor. Sometimes a very low dose anti-depressant can shut down some of this a little bit. Wishing you good luck.

Maybe an anxiety medication would be good for him.