Question

When we nibble at a rusk, we hear a noise that is simply deafening. But for some reson, our neighbour makes hardly any noise though he is doing the samed. Why ?

Answer 1

The bones of our head are solid elastic bodies and as such are very good conductors of sound. In a denser medium, the sound is louder. When we nibble at the rusk, the weak sound so produced reaches the auditory nerves via the solid bones of the head (through bone conduction) and as such becomes very loud. But when our neighbour does the same thing, this weak sound has to travel through air and as such is faint.