Ginger and Bramble, 
      I don't quite know if there would be an infection or not. 
      Usual infection has symptoms other than just sound sensitivity. 
      
Like: Shakes head and scratches at her ears, or exudes a pungent smell 
      from ear. 
      We clean with white distilled vinegar 50/50 solution, and make sure 
      emmett's ears are all dry before he returns outside. 
      Might just be safe to get her checked out to make sure there is nothing 
      wrong like an infection or a middle or inner ear problem. 
      If it is a fear or anxiety . . . desensitization and 
      counter-conditioning are methods of treatment, and also medication. I 
      would try the first two before the later one though.Maybe record and then 
      play the some of the sounds to her on a tape recorder at a very low level, 
      and reward her when no fear shown. Then gradually increase the volume over 
      a period of two week or so; all the while, still rewarding when no fear is 
      shown. 
      No expert here, just advise IMHO. A vet and trainer would know more 
      about what is going on in seeing her and watching her react. 
      Hang in there with her could be just a stage, and give us 
      updates.
      Pyrsmyles, Mer & Emm 
       
      *The behavior that receives the most attention, is the behavior that 
      will happen the most.