I have a 4-year old dog who, at times, is very fearful. We can deal with her fearfulness, but the problem we can't seem to resolve is her sensitivity to noise. If someone slams a car door outside and turns the alarm on, she will start to growl. If she hears kids playing outside, she will start to bark. Finally, if someone rings the bell, she will bark at will until finally I must stand in front of her, blocking her view from anything, and tell her to stop. I like that she barks on the initial door ring or door opening, but long after the event is over, she is still barking; let's say, 5 minutes.
Any tips to help desensitize my dog to noise?