The White House East Room floor was packed yesterday with 178 excited children, but you could hardly hear a sound.

They were from Kendall School, the federally funded elementary school at Gallaudet College for the Deaf, and they were here for a Christmas party featuring Virl and Tom Osmond, of the Osmonds, and the great dancer Jacques d'Amboise, who now runs the National Dance Institute in New York for hearing-impaired children.

It was Mrs. Reagan's idea, and when she came in, wearing a pink and gray knit dress with ruffled shirt (in the style of Chanel, according to authorities at the scene), she sat right down with the children. Right away she learned to sign some words. She also read messages scrawled on paper and held up for her. One small girl hung onto her hand the whole time, like a talisman.

The Osmond brothers -- Tom is 90 percent deaf and Virl deaf in the left ear -- did a pretty good dance with top hats and canes, then played Christmas carols on the saxophone, piano, Swiss bells and xylophone. Finally they signed "We Wish You a Merry Christmas" and the whole audience joined in, some signing and some singing along. Many of Gallaudet's staff were there, and the children's teachers stood at the fringe.

D'Amboise had 13 of his kids on hand. "This is our first rehearsal," he told the first lady. "Wow, what a rehearsal!" His institute is about to launch a dance-for-the-deaf program for 1,000 children in New York. They dance to drumbeats. They do a lot of leaping. Peter McCarrick, 14, leaped over a huge pile of people.

This time he slipped, but in the past he has jumped over 16 prone adults. D'Amboise taught him to land with a "ta-da!" -- chest and arms outflung. "He's amazing," the dancer said later. "Absolutely deaf. I didn't know it for six months because he could read my lips." Another young soloist was Greg Scheuer, 12, who moved with energy, ebullience and e'clat and performed a dance, "40 Counts," that he had composed himself.

Some rather flamboyant people greeted the young guests. They were local actors who had volunteered their time, and were wearing costumes loaned by Henri Bendel: a chef with an onion necklace, a queen with a castle on her head, a blackbird, a dove, a lady in tricorn hat and a couple of mimes in classic white ruffles and black skullcaps who did tricks with their faces.

At the end, tiny Maureen Yeats, 6, with long silvery blond hair, gave Mrs. Reagan a present from Kendall School. It was the hair that got her the job, a teacher said: "She looked just like Alice in Wonderland." Afterward, Mrs. Reagan gave some presents herself, and everyone had cider and cookies.

"I hope you enjoyed everything," Mrs. Reagan said, "the tree and everything. I'm so happy to have you here, and . . ."

She signed: I love you.