Some of California's most dangerous inmates should be getting more sleep under an agreement that requires guards to hold down the noise.

Dozens of prisoners complained that they were being kept awake around the clock by overnight welfare checks every half-hour.

An agreement announced on Thursday requires guards in Pelican Bay State Prison's notorious security housing unit to conduct the checks half as often between 10 p.m. and 6 a.m.

The change will continue while state corrections officials try to figure out ways to minimize the clanging of metal doors.

The checks began in August as a way to deter suicides. But attorneys representing inmates say the resulting sleep deprivation was causing health problems and psychological stress.

Guards are even handing out earplugs to help inmates rest.