with time and support they learn to build tolerance to all sensory stimuli. It could be that there is other stimuli impacting her along with the sound sensitivity and thats why she is overwhelmed. My son is more prone to his sensory when he is tired, hungry, or feeling under the weather. Try to keep a journal, every time she reacts to sound that way, take note where it is happening, what is going on around her environment, is she tired? Is she hungry?(hangry) how is her health that day? What clothes shes wearing (sensory wise if its a material causing her stimuli it contributes to her ability to tolerate). etc... After a week or several incidents you might be able to pick up a pattern or clues to what is contributing to her sudden intolerance to certain sounds. It's amazing but even the smallest little thing that you wouldn't even consider can disbalance a sensitive child.

My son used to cover his ears whenever I used the vacuum cleaner, blender, the hand dryer or even toilet flushing in the public restroom. He didn’t like the sound of the garbage truck or sirens, either. He eventually outgrew it. Now, he is distracted by them and gets excited. He is a freshman in high school now. I bought him ear mufflers when he was in first grade for school or when we went out for errands or family outings just in case.

My son has the same issue. It partially goes away as he grows up. He is OK for vacuum sound now. But he still doesn't like blender sound and other louder sounds. I bought him an ear muffler when he turns 9. He can use it whenever he needs it.

Around the same age

My son had a seizure disorder and i attributed those changes to that, for instance the vacuum was a favourite item to socialize over, then it became shocking and unbearable all of a sudden, plus kiddo seemed confused, as though not really hearing it before.