What can I do about living above a Mentally Challenged individual who bangs on the walls throughout the day and night?

I have spoken to my landlord multiple times about the disturbances and have video and audio recordings. He states that he has spoken to them multiple times but he noises haven't ceased. It is keeping us awake at night and waking us very early in the morning, ultimately hurting us and our sleep habits. There are no other apartments available to switch to and it seems the landlords haven't taken any further steps to fix the situation other than talking to them. What can I do?