displaced aggression in my cat...cats

Question
I am concerned for myself and another cat I live with. I have two cats, male and female, brother and sister. On three occassions  (aprox. 6 months time between episodes) my male cat Tiger attacked me and his sister after hearing loud noises.  First time we were indoors in my small apartment and my neice ran up my stairs and pounded on my door loudly...excited to see me.  My cats started attacking each other. Ruff and tumble. Second time was outside in the yard. Feather (the female) caught a mole and I yelled at her to drop it..Tiger ran across the yard to where we were and attacked her then me, her then me..it was crazy. Most recently, and the worst injury to me..several bad scratches...was in the apartment after i yelled "Tiger".....to get him to stop eating a plate full of cupcakes.  Feather ran in from the other room and they both attacked each other and then me...each other and then me.  I threw a blanket over Feather and took her and myself to the bathroom, closed the door.  Waited for both to calm down.  I am told this is displaced aggression.  NO Kidding. What can i do to resolve the attacks?  Please help us....I love them both. They are almost three years old.  Both fixed, all up to date on vaccines.

Answer
Well you are correct in stating that this is a danger to both of you. Apparently Tiger is very sensitive to loud noises. This could be so painful for him that his only recourse is to attack the nearest thing- you and his sister.

My suggestion would be a complete check up for him and possibly some medication for his hearing or nerves. He could be the kind of cat that these noises set off an almost seizure-like response in him. When that happens the cat can become very agitated and aggressive.

If the physical doesn't reveal anything then a chemical solution might be your best bet here.
It could be purely behavioral as well but it doesn't sound like it is.

Make an appointment soon for him.