Can someone please tell me what book I can find the short story "The sound of silence" in please? Thank you

You mean "A Sound of Thunder"?

I couldn't recognize the title, either, Dandelion. All I could think of was Simon and Garfunkel. You're probably right that they are looking for "A Sound of Thunder". If so, it is in:

THE STORIES OF RAY BRADBURY. Ray Bradbury. Knopf, NY. 1980.

R IS FOR ROCKET. Ray Bradbury. Bantam/Doubleday, NY. 1962.

THE GOLDEN APPLES OF THE SUN. Ray Bradbury. Perennial/HarperCollins, NY. 1990.

It may also be in others.

Only one I know of is Bradbury's:

'Dwellers in Silence'

...published, 1948

He wrote one titled "The Silence," also known as "And Then--the Silence," but it's quite rare and I'm sure uncollected.