Spencer seems much more sensitive to new things, especially noises, than Bruno ever was. It's a little insecurity that I have noticed in him since day one when he did not want to walk on the hard flooring inside the house. We have to be very careful not to nurture this in him, but rather make him stronger minded. Sometimes it's not always easy as it's due to other humans reacting to him.
For example, at the vet he started becoming unsure about being up on the table after getting his anal glands checked. I mean who wouldn't, right? Spencer's tail went between his legs which indicated that he was very unsure at the moment. I knew this meant we had to not give him any type of affection until he gathered his wits and realized everything was going to be OK. However, the vet tech noticed he was not so sure and sweet-talked him. Sure, his tail wagged at her, but then he started to shake up on the table. Without realizing it, the vet tech just told him he was a good boy for being unsure, instead of telling him there was nothing to be afraid of. However a dog is feeling at the time you give them affection (including sweet words) is the feeling you are encouraging. Spencer was just encouraged to be afraid.
At home I deal with his sensitivity by associating something positive with the noise he is unsure about. I am careful not to sweet-talk or pet him. I stay calm and quiet. For example, I had just gotten something out of the cabinet. When the cabinet door slammed shut Spencer jumped and ran away from the area. I gently but firmly told him to come back. When he did I had him sit down and made cabinet noises, not as loud as the one that freaked him out but it was the same sound. Spencer had tried to walk away a few times but I gently blocked him and told him to stay. I started letting him smell things inside the cabinet while making cabinet noises. I took one item out at a time and held it for him to smell. I did not want to teach him to nose in the cabinet on his own so I was careful to be the one showing. He started to lighten up as he started to become more interested in the new smell of the items and less on the noise, while I was staying careful not to talk to him in a sweet way but a matter-of-fact, calm but firm way. Then I held a chewy bone out for him while I made cabinet noises. Spencer started to totally ignore the sound of the cabinet even when the noises got louder and was chewing his bone while I was holding it. Suddenly the cabinet was no big deal to him. Had I given him love or affection while he was freaked out about the cabinet I would have been telling him good boy for being afraid. Instead I first showed him the cabinet, showed him what was in it, and then associated the noise of the cabinet with a chewy bone.