California corrections officials are handing out earplugs and telling guards to walk softly around some of the most dangerous inmates after they complained about noise.

The prisoners say new welfare checks at Pelican Bay State Prison's notorious security unit are keeping them awake because noise caused by guards rouses them every half-hour around the clock.

Nearly 70 noise complaints have been filed at Pelican Bay since the checks began last month.

Officials said Thursday they are training correctional officers to complete the checks as quietly as possible and exploring ways to quiet clanging doors.

The checks have been used at other prisons for nearly a decade and are intended to deter suicides.

The unit houses gang leaders and those who commit serious crimes behind bars.