Question

Why are metals sonorous and non metals are non sonorous?

Answer 1

Electron bonding in metals is highly delocalized, due to their very low electronegativity. This means that when struck, the electron cloud moves extremely easily - there is very little energy dissipated. This allows the incoming kinetic energy to be easily propagated as a form of disequilibrium - a sound wave.

While electron bonding not delocalized in non metal.So it hasn't that much electron cloud to move easily.So
incoming kinetic energy(struck on the object) is converted to some other forms.