Hey Gnome Nation : So how do sound waves change when you turn up the volume on your radio? #Hashtag180… https://t.co/P3aV51qdPg

Hey Gnome Nation : So how do sound waves change when you turn up the volume on your radio? #sci6p13 #Hashtag180 #SalemProud http://pic.twitter.com/k5xf9uFiww

— Bill Ferriter (@plugusin) June 1, 2017

Here is a good visual representation of longitudinal waves. For and explanation of amplitude in transverse and longitudinal waves, see this video.