Hi June,
Young babies are very prompt to shock, don't need to worry so much. My bb 'jumped' when I switched on the light / talked in a slight louder voice / opened the door, just a slight noise will make him 'jumped'. As they grow older, the shock will get lesser. In a few mths time, yr bb will not be so easily shock. My bb only stir a little when he heard some noise, unless it's very loud, then he'll get a shock.
I tried using bean bag, it helps a little. As what Susanna and Beezewax had shared, wrap yr bb tightly, it will help him or her to feel more secure and not get shock so easily.