English definition of “sound”
› [C, U] something that you hear or that can be heard: I could hear the sounds of the city through the open window. She stood completely still, not making a sound. Can you turn the sound up (= make a radio, television, etc louder)?
the sound of sth informal › how something seems to be, from what you have been told or heard: I like the sound of the beef in red wine sauce. He's really enjoying college, by the sound of it.