Son (sound)
Son
Latin sonus: sound.
The class sang the national anthem in unison.
Unison
In unison: all together at the same time, as if with one voice.
The students answered 'Good morning' in unison.
Supersonic
Faster than the speed of sound.
A supersonic jet can fly faster than sound travels.
Remember: Son = sound: sonic, resonate (sound again, echo), dissonance (sounds that clash). Caution: son (a child) is an Old English word, not from sonus.