Greetings! On my canon lenses with IS (24-105, 70-200) I can ALWAYS feel the gyro operating, and sometimes I can hear the whir if I listen carefully (and my ears are not ringing horribly). However, I feel No tactile or auditory indication on the 18-55 2.8-4 when the switch on the lens is in "on" position. Is this normal? Thanks!