Some stores here play the same songs all day — and play them loudly. Employees say shifts have become unbearable.
"To listen to it for eight hours a day is not healthy, that's for sure," said Alexandr Leiner, a union leader. "And for the customers, it's almost unbearable as well."
Leiner said unions have written to major chains, such as Tesco, and demanded that employees be compensated. He said the unions want 500 koruna ($19) or two days off as a possible compensation. They've received no response.
Tesco spokesman Vesselin Barliev said the chain has not received any complaints.
"We don't see the music as a problem," Barliev said.
Unions in neighboring Austria have lodged similar complaints against stores there. Labor unions are pressing stores to stop the incessant playing of carols, denouncing the practice as "psychological terrorism" that grates the ears of shop employees.
"They become aggressive and develop an aversion to Christmas music," said Gottfried Rieser, a leader of the campaign. "It gets to the point where on Christmas Eve, when they're at home with their families, they can't stand 'Silent Night' or 'Jingle Bells' one more time."
Rieser wants shops to limit carol playing to one hour - 3 p.m. to 4 p.m. - to give workers a break. "There's no sense in playing 'Softly Falls the Snow' in the sausage department," he said.
Earlier this month, The Arizona Republic listed what its interviews suggested were considered the worst Christmas carols.
Among the picks: "Jingle Bell Rock" by Bobby Helms, "The Twelve Days of Christmas" by the Ray Coniff Singers, Jimmy Durante's version of "Frosty the Snowman," "We Wish You a Merry Christmas" by Stu Goldberg, "Feliz Navidad" by Jose Feliciano, "Here Comes Santa Claus" by Gene Autry.
Also on the Republic's naughty list: "Jingle Bells" when sung by dogs, "I Saw Mommy Kissing Santa Claus" when sung by a child, and "Christmas Don't Be Late," the high pitched classic by Alvin & the Chipmunks.