LONDON — Dim the lights. Silence the piped-in music. Turn down the checkout beeps. For an hour on Saturdays, a British supermarket chain is introducing a weekly “quieter hour” aimed at helping people with autism have a better shopping experience by easing sensory overload.

The move by the supermarket, Morrisons, which begins on Saturday and runs from 9 a.m. to 10 a.m., has been welcomed by the National Autistic Society, which says that even small changes can make a big difference in the lives of people with autism and their families.

“Around 700,000 people are on the autism spectrum in the U.K.,” Tom Purser, of the National Autistic Society, said in an email. “This means they see, hear and feel the world differently to other people, often in a more intense way, which can make shopping a real struggle.”

Autism is a lifelong developmental disability that affects how people communicate and relate to others and how they experience the world around them. More than 60 percent of people with autism avoid shops, and 79 percent say they feel socially isolated, according to figures published by the society.