i Register
In some senses, swing-swang is marked as archaic. Watch for register when choosing this word.
noun
A complete oscillation.
Thus, in the present case, the air in one second of time makes 512 swing-swangs or vibrations both ways, that is, 1024 simple swings each way, that is, simple vibrations, as the French call them, in one second.
adj
Swinging.
Drawling; sing-song.